bluuebunny/crossref_metadata_2025 huggingface dataset:
Alveolar macrophages from subjects infected with HIV-1 express macrophage inflammatory protein-1α (MIP-1α): contribution to the CD8+ alveolitis
Authors: DENIS M , GHADIRIAN E
Published: July 2010

We examined the synthesis and release of MIP-1α in alveolar macrophages obtained from normal subjects or subjects infected with HIV-1, at different stages of the disease. HIV-1-infected subjects in groups II, III and IV all had significant interstitial pneumonitis, featuring a significant infiltration of CD8+ lymphocytes in the bronchoalveolar lavage. Alveolar macrophages from HIV-1-infected subjects were shown to express significant levels of MIP-1α via immunohistochemistry, both spontaneously and in response to lipopolysaccharide (LPS), whereas cells from normal subjects expressed very low levels of the cytokine. Supernatants of alveolar macrophages from HIV-1-infected subjects exerted strong chemotactic activity for purified activated blood CD8+ T lymphocytes, which was strongly inhibited by neutralizing MIP-1α. Studies of patients with HIV-1 infection at different stages of the disease showed that MIP-1α secretion increased as viral infection developed, There was a significant positive correlation between MIP-1α secretion and the CD8+ alveolitis in HIV-1-infected subjects. Infection of alveolar macrophages in vitro with three distinct strains of HIV-1 which replicated profusely in macrophages did not induce the expression of MIP-1α. Collectively, these data suggest that HIV-1 infection in vivo induces MIP-1α expression and release in alveolar macrophages, and this appears to contribute significantly to the alveolar lymphocytosis seen in HIV-1-infected subjects.
Binding of pentraxins to different nuclear structures: C-reactive protein binds to small nuclear ribonucleoprotein particles, serum amyloid P component binds to chromatin and nucleoli
Authors: PEPYS M B , BOOTH S E , TENNENT G A , BUTLER P J G , WILLIAMS D G
Published: July 2010

Binding of the human pentraxin plasma proteins, C-reactive protein (CRP) and serum amyloid P component (SAP), to the nuclei of human cells was studied using whole acute phase serum as the source of the proteins and confocal immunofluorescence microscopy. CRP and SAP clearly bound to distinct, different structures. Double staining with MoAbs to the Sm D and Sm B/B′ components of small nuclear ribonucleoproteins confirmed that CRP bound exclusively to these particles. As expected. SAP bound to chromatin and. in addition, binding to the nucleolus was observed for the first time. These interactions demonstrated under relatively physiological conditions, with native pentraxins unseparated from serum and with nuclear constituents in situ, are likely to be of functional importance in vivo.
Endothelial cell activation by tumour necrosis factor-alpha (TNF-α and the development of pre-eclampsia
Authors: MEEKINS J W , McLAUGHLIN P J , WEST D C , McFADYEN I R , JOHNSON P M
Published: July 2010

Pre-eclampsia may develop as a result of an endothelial activation. Tumour necrosis factor-alpha (TNF-α) activates endothelial cells which release soluble E-selectin, a putative circulating marker specific for endothelial damage. A retrospective longitudinal study of maternal blood samples, collected at different gestational ages in pregnancy, was undertaken to determine whether the development of pre-eclampsia is associated with TNF-α-mediated endothelial activation. This study included 19 women who developed pre-eclampsia and 22 women whose pregnancy outcome was normal. Ten women had blood samples taken before pre-eclampsia was clinically detected and, in all these, TNF-α was below the immunoassay limit of detection (< 80 pg/ml). Five had further samples taken after pre-eclampsia was clinically diagnosed and, initially, TNF-α was still below the lower limit of detection in all five pregnancies, but rose later in three (80, 156 and 250 pg/ml). In nine other patients with diagnosed pre-eclampsia, TNF-α was detected in only two (80 and 650 pg/ml). TNF-α was identified in only one of the 22 normal pregnancies (80 pg/ml), this being at term. There was no statistical difference in soluble E-selectin levels between normal and pre-eclamptic pregnancies, neither before nor after pre-eclampsia was diagnosed. Hence, blood TNF-α levels measured by immunoassay can be elevated in approximately 36% of cases of established preeclampsia, but this rise occurs only after the syndrome is detected clinically. Blood concentrations of TNF-α and soluble E-selectin are not related to severity of the disorder. These findings suggest that circulating TNF-α does not contribute to the initiation of endothelial cell activation that may be associated with the development of pre-eclampsia, but may rise as a consequence of the pathological processes of this disorder.
Tetanus toxoid-specific T cell responses in severe combined immunodeficiency (SCID) mice reconstituted with human peripheral blood lymphocytes
Authors: SOMASUNDARAM R , JACOB L , HERLYN D
Published: July 2010

SCID mice reconstituted with human peripheral blood lymphocytes (PBL) have repeatedly been shown 10 produce antigen-specific B ceil responses. We have derived tetanus toxoid (TT)-specific human T cell lines from cells of the peritoneal cavity, spleen and lymph nodes of SCID mice reconstituted with human PBL and boosted with TT. Establishment of these cell lines was dependent on the time interval between reconstitution of the mice with human PBL and initiation of lymphocyte cultures in vitro. When lymphocytes were collected from the mice 8 weeks after reconstitution, human lymphocytes with TT-specific proliferative activity in vitro were isolated from the peritoneal cavity and spleen, but long-term cell lines could not be established after repeated lymphocyte stimulation with TT. IL-2 and autologous Epstein Barr virus-transformed B cells. In contrast, three long-term (>10 months) TT-specific human T cell lines were established from lymphocytes collected from two of the eight mice in the group 4 weeks after reconstitution. The T cell lines were either CD4+ (two lines derived from peritoneal cavity and lymph node, respectively) or CD8+ (one line derived from spleen) and all expressed CD3, T cell receptor α/β, and human histocompatibility leucocyte class I antigen. The T cell lines, however, lacked cytotoxic, helper and suppressor activities. Thus, SCID mice can support human T cells that actively migrate to various organs and respond to antigenic stimuli both in vivo and in vitro, but these T cells lack characteristic functions.
Bactericidal/permeability-increasing protein (BPI) is an important antigen for anti-neutrophil cytoplasmic autoantibodies (ANCA) in vasculitis
Authors: Zhao M H , Jones S J , Lockwood C M
Published: July 2010

Indirect immunofluorescence (IIF) techniques have shown that ANCA are useful serological markers for some small vessel vasculitides, and ELISA assays, using purified molecules as solid-phase ligand, have helped to identify proteinase 3 (PR3) and myeloperoxidase (MPO) as two of the major ANCA antigens. There remain a substantial number of serum samples, which are positive by IIF, yet recognize neither PR3 nor MPO (double-negative samples). We found, by Western blot analysis of soluble neutrophil granule proteins, that certain of these double-negative samples recognized a 55-kD doublet of which the first eight residues shared N-terminal amino acid sequence homology with BPI, a potent antibiotic towards Gram-negative bacteria. We developed a simple, quick and robust two-step immunobiochemical method to purify BPI. This was then employed to detect anti-BPI autoantibodies by ELISA and Western blot analysis. We tested 100 double-negative samples and 400 consecutive new samples sent for routine ANCA testing in the anti-BPI ELISA. We found that 45 of the 100 double-negative and 44 of the 400 new routine samples recognized BPI. By Western blot analysis 20/20 positive anti-BPI samples blotted the 55-kD protein. Inhibition assays confirmed the specificity of binding. Review of the 89 anti-BPI-positive patients showed a male dominance (M: F ratio 55:34), a mean age of 60.4 years and clinical diagnoses ranging from organ limited vasculitis to widespread systemic vasculitis.
IL-8/IL-8 receptor expression in psoriasis and the response to systemic tacrolimus (FK506) therapy
Authors: Lemster B H , Carroll P B , Rilo H R , Johnson N , Nikaein A , Thomson A W
Published: July 2010

Recently, the keratinocyte IL-8/IL-8 receptor (IL-8R) pathway has been implicated in the pathogenesis of psoriasis, and there is evidence that the potent macrolide immune suppressant tacrolimus (formerly FK506) can inhibit this pathway in vitro. In this study, determination of the expression of cytokine mRNAs in lesional skin of patients with active disease by reverse transcriptase polymerase chain reaction revealed transcripts for IL-1β, tumour necrosis factor-alpha (TNF-α), IL-6, IL-8, IL-8R, IL-10, interferon-gamma (IFN-γ), IL-2R and transforming growth factor-beta (TGF-β), but not IL-2 or IL-4. IL-8 was the only cytokine expressed in affected skin of all patients but not in clinically normal skin of healthy subjects. In seven CD4+ T cell clones propagated from the lesional skin of an untreated psoriasis patient, IL-8 was expressed by the skin-derived T lymphocytes and not by feeder cells (irradiated autologous blood lymphocytes); IL-1β, IL-2, IL-6 and IL-10 were also expressed by some or all of the T cell clones, IL-8 mRNA was not detected in the skin of any patient after the start of systemic tacrolimus therapy; IL-lβ, IL-6 and IFN-γ transcripts were also reduced. By 12 weeks, the mean psoriasis area and severity index (PASI) had decreased from 18·8 to 3·8, a reduction of 80%. In the same post-treatment biopsies, however, message for IL-8R persisted. Estimation of circulating IL-8 levels by enzyme immunoassay showed that all patients with detectable IL-8 before treatment had decreased levels in response to treatment with tacrolimus; reductions in PASI scores were accompanied by decreases in IL-8 levels, that varied both in rate and extent. Partial relapse, which in a minority of patients followed the initial period of remission, and was precipitated by drug dose reduction, was accompanied by an increase in circulating IL-8. These findings add credence to the view that the IL-8/IL-8R autocrine/paracrine pathway may be important in the pathogenesis of psoriasis. They further suggest that interference with IL-8 production and/or that of other key chemokines may be an important mechanism underlying the therapeutic efficacy of tacrolimus, and other agents such as cyclosporin A, with similar molecular actions.
Cytokine production by normal human monocytes: inter-subject variation and relationship to an IL-1 receptor antagonist (IL-1Ra) gene polymorphism
Authors: Danis V A , Millington M , Hyland V J , Grennan D
Published: July 2010

Monocytes from different individuals show variable cytokine production in response to a variety of stimuli. We wished to determine the sets of conditions (cytokine combinations) that would enable us to demonstrate stable inter-individual differences in the production of IL-1α, IL-1β, IL-1Ra, IL-6 and tumour necrosis factor-alpha (TNF-α) by monocytes. We assessed the ability of a number of recombinant human cytokines (granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), TNF-α, IL-4, IL-6, transforming growth factor-beta (TGF-β), IL-10 and IL-1Ra) to stimulate or inhibit the production of one or more of these monocyte products. GM-CSF was found to stimulate the production of all five of these cytokines in a highly reproducible manner. TNF-α also up-regulated production of IL-1α, IL-1β, IL-1Ra and IL-6 by monocytes, but the variability in the results of cells cultured from the same individuals on different occasions was greater. Other cytokines either stimulated production of only some of the five cytokine products tested, or stimulated the production of some cytokine products while inhibiting production of others. This was especially evident when cytokines were used in combination with GM-CSF: IFN-γ down-regulated production of IL-1Ra while up-regulating the production of IL-1α/β, IL-6 and TNF-α, while IL-4 had the exact opposite effect. Polymorphisms in regions of cytokine genes that affect transcription may account for some of the inter-individual variation in cytokine production. We have shown that a stable estimate of cytokine production phenotype can be obtained when monocytes collected on at least two separate occasions are stimulated by GM-CSF in vitro. We have looked for a relationship between IL-1 production and an 86-bp variable repeat polymorphism in intron 2 of the IL-1Ra gene. A less common allele of this polymorphism (allele 2) was associated with increased production of IL-1Ra protein, and also reduced production of IL-1α protein by monocytes.
Analysis of proteins that interact with the IL-2 regulatory region in patients with rheumatic diseases
Authors: BECKER H , STENGL G , STEIN M , FEDERLIN K
Published: July 2010

In order to investigate transcriptional regulation of lymphokine genes in rheumatic diseases, peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) were analysed for expression of DNA-binding proteins. Nuclear extracts prepared from unstimulated and mitogen-activated cells were studied for their ability to bind to 32P-labelled oligonucleotides containing the AP-1, NF-AT, NF-B and CD28RC sites of the IL-2 promoter. Using gel mobility-shift assay, detection of protein binding to the AP-1 site was reduced in SLE compared with controls. NF-AT binding activity was enhanced in all groups of patients, and was associated with measures of disease activity in RA. In addition. SSc patients showed increased NF-×B binding activity. Altered patterns of DNA-binding proteins suggest disturbed intracellular signalling which may contribute to abnormal lymphokine production in rheumatic diseases.
Rabbit polymorphonuclear granulocyte function during ethanol administration—migration and oxidative responses in a joint with immune complex synovitis
Authors: Nilsson E , Thomsen P , Ericson L , Palmblad J
Published: July 2010

Functional impairments of polymorphonuclear granulocytes (PMN) are believed to contribute to hampered inflammation and host defence in alcoholics. We studied effects of i.v. ethanol administration on PMN responses in rabbits during induction of a knee-joint synovitis. The synovitis conferred systemic effects, since chemiluminescent responses of peripheral blood PMN to opsonized zymosan and phorpbol myristate acetate (PMA) increased 64- and 17-9-fold, respectively. Chemiluminescent responses of synovial PMN were further amplified. This up-regulation was reduced to 33% in rabbits treated with ethanol when opsonized zymosan was used as the PMN stimulus: in contrast, PMA responses were unaffected. The appearance and migration of PMN to the synovitis joint were normal despite a blood ethanol concentration of 0-5%. Thus, ethanol impaired release of oxygen metabolites from PMN, but not the delivery of cells at an inflammatory site.
Detection of enteroviruses in the intestine of type 1 diabetic patients
Authors: Oikarinen M , Tauriainen S , Honkanen T , Oikarinen S , Vuori K , Kaukinen K , Rantala I , Mäki M , Hyöty H
Published: July 2010

Enterovirus infections have been diagnosed more frequently in type 1 diabetic patients than in the healthy population, and enteroviruses have also been found in the pancreas of diabetic patients. Primary replication of the virus occurs in the gut, but there are no previous studies evaluating possible presence of virus in the intestine of diabetic patients. The purpose of this study was to investigate if enteroviruses can be found in small intestinal tissue of type 1 diabetic patients. Formalin-fixed, paraffin-embedded upper intestinal biopsy samples were analysed for the presence of enterovirus using in situ hybridization and immunohistochemistry. Enterovirus was detected by in situ hybridization in six (50%) of the type 1 diabetic patients (n = 12) but in none of the control subjects (n = 10, P = 0·015). Immunohistochemistry identified enterovirus in nine (75%) of the patients and one (10%) control subject (P = 0·004). The presence of the virus was confirmed by reverse transcription–polymerase chain reaction in one of the four patients from whom a frozen and unfixed sample was available. Intestinal morphology was normal in all study subjects. The results suggest that a substantial proportion of type 1 diabetic patients have an ongoing enterovirus infection in gut mucosa, possibly reflecting persistent enterovirus infection. This observation opens new avenues for further studies on the possible role of enteroviruses in human type 1 diabetes.
Stimulation by means of dendritic cells followed by Epstein–Barr virus-transformed B cells as antigen-presenting cells is more efficient than dendritic cells alone in inducing Aspergillus f16-specific cytotoxic T cell responses
Authors: Zhu F , Ramadan G , Davies B , Margolis D A , Keever-Taylor C A
Published: July 2010

Adoptive immunotherapy with in vitro expanded antigen-specific cytotoxic T lymphocytes (CTLs) may be an effective approach to prevent, or even treat, Aspergillus (Asp) infections. Such lines can be generated using monocyte-derived dendritic cells (DC) as antigen-presenting cells (APC) but requires a relatively high volume of starting blood. Here we describe a method that generates Asp-specific CTL responses more efficiently using a protocol of antigen presented on DC followed by Epstein–Barr virus (EBV)-transformed B lymphoblastoid cell lines (BLCL) as APC. Peripheral blood mononuclear cells were stimulated weekly (2–5×) with a complete pool of pentadecapeptides (PPC) spanning the coding region of Asp f16 pulsed onto autologous mature DC. Cultures were split and stimulated subsequently with either PPC-DC or autologous PPC-pulsed BLCL (PPC-BLCL). Lines from the DC/BLCL arm demonstrated Asp f16-specific cytotoxicity earlier and to a higher degree than lines generated with PPC-DC alone. The DC/BLCL-primed lines showed a higher frequency of Asp f16-specific interferon (IFN)-γ producing cells but an identical effector cell phenotype and peptide specificity compared to PPC-DC-only-primed lines. Tumour necrosis factor (TNF)-α, but not IL-10, appeared to play a role in the effectiveness of BLCL as APC. These results demonstrate that BLCL serve as highly effective APC for the stimulation of Asp f16-specific T cell responses and that a culture approach using initial priming with PPC-DC followed by PPC-BLCL may be a more effective method to generate Asp f16-specific T cell lines and requires less starting blood than priming with PPC-DC alone.
99th Dahlem Conference on Infection, Inflammation and Chronic Inflammatory Disorders: Lifestyle changes affecting the host–environment interface
Authors: Ehlers S , Kaufmann S H E
Published: July 2010

In industrialized nations and high-income regions of the world, the decline of infectious diseases is paralleled by an increase in allergic, autoimmune and chronic inflammatory diseases (AACID). Changes in lifestyle in westernized societies, which impact individually and collectively on intestinal microbiota, may – at least in part – account for the AACID pandemic. Many disease genes that contribute to AACID encode pattern recognition and signalling molecules in barrier-associated cells. Interactions between gene products and environmental factors depend highly upon the host's state of maturation, the composition of the skin and gut microflora, and exposure to pollutants, antibiotics and nutrients. Inflammatory stress responses, if regulated appropriately, ensure immunity, health and relative longevity; when they are dysregulated, they can no longer be terminated appropriately and thus precipitate AACID. The 99th Dahlem Conference brought together experts of various disciplines (genetics, evolution biology, molecular biology, structural biology, cell biology, immunology, microbiology, nutrition science, epidemiology and clinical medicine) to discuss the multi-faceted relationships between infection, immunity and inflammation in barrier organs and the development of AACID. In Clinical and Experimental Immunology we are presenting a compilation of background papers that formed the basis of discussions. Controversial viewpoints and gaps in current knowledge were examined and new concepts for prevention and treatment of CID were formulated.
99th Dahlem Conference on Infection, Inflammation and Chronic Inflammatory Disorders: Caenorhabditis elegans as a model to study tissues involved in host immunity and microbial pathogenesis
Authors: Irazoqui J E , Ausubel F M
Published: July 2010

The molecular mechanisms involved in host–microbe interactions during the initial stages of infection are poorly understood. The bacteria-eating nematode Caenorhabditis elegans provides an opportunity to dissect host–microbe interactions in the context of the whole organism, using powerful genomic, genetic and cell-biological tools. Because of the evolutionary conservation of ancient innate host defences and bacterial virulence mechanisms, studies in C. elegans hold great promise to shed light on defences in higher organisms, including mammals. Additionally, C. elegans pathogenesis models provide a platform for the identification of novel classes of anti-infective compounds with therapeutic value.
Revealing secret liaisons: DNA barcoding changes our understanding of food webs
Authors: KAARTINEN RIIKKA , STONE GRAHAM N. , HEARN JACK , LOHSE KONRAD , ROSLIN TOMAS
Published: July 2010

1. How food webs are structured will affect how species dynamically interact. To date, the construction of quantitative food webs has largely been based on morphological species characters. Yet, recent work suggests that the use of molecular characters may change our perception of both species limits and species identity.

2. Focusing on an assemblage of natural enemies of specialist herbivores, we used DNA sequence ‘barcode’ identification for three purposes: to screen the focal web for morphologically cryptic species, to catch misidentified individuals and to re‐examine key descriptors of food web structure.

3. Based on morphological characters, we were able to distinguish 51 parasitoid species and 5 inquilines. Molecular markers revealed four morphologically cryptic parasitoid taxa and completely changed our view of species limits among the inquilines, defining six molecular operational taxonomic units (MOTUs) with little resemblance to the original five morphospecies.

4. In total, the use of DNA barcode information changed the species designation of 31% of the sequenced individuals. However, measures of food web structure changed relatively little, reflecting the fact that the cryptic taxa detected by us accounted for only a minor proportion of interactions in the overall food web. Qualitatively, web metrics suggested higher specialisation of parasitoid species in molecularly informed than in purely morpohologically‐based webs.

5. Taken together, this study suggests that the added resolution offered by molecular information contributes a new level of precision to food web studies. Overall, it depicts interactions within the food web as more specialised than revealed by morphological species characters. Importantly, molecular markers will also allow us to match morphologically cryptic taxa sampled among regions, and thereby to compare the ecological role of individual species in different communities.
Will climate change reduce the effects of a pesticide on amphibians?: partitioning effects on exposure and susceptibility to contaminants
Authors: ROHR JASON R. , SESTERHENN TIMOTHY M. , STIEHA CHRISTOPHER
Published: July 2010

Several studies suggest that global climate change could increase the toxicity of contaminants, but none of these studies explicitly integrate the effects of climate change on both susceptibility and duration of exposure to pollution. For many amphibian and aquatic insect species, exposure to contaminants is probably greatest during their fully aquatic embryonic and larval stages because these stages cannot readily escape water bodies where many contaminants accumulate and concentrate. Hence, by accelerating embryonic and larval development, global warming might reduce the duration of contaminant exposure for these taxa. To test this hypothesis, we isolated the effects of a temperature gradient (13–25 °C) on susceptibility (toxicity at a controlled exposure duration) and exposure of the streamside salamander, Ambystoma barbouri, to the herbicide atrazine (0, 4, 40, and 400 μg L−1) by quantifying growth, survival, hatching, and metamorphosis under an atrazine exposure duration that was either constant or that depended on time to metamorphosis (and thus temperature). Increasing atrazine concentrations reduced growth, delayed hatching and metamorphosis, and decreased embryonic and larval survival. Increasing temperatures enhanced growth, accelerated development, and reduced survival for embryos but not larvae. With the exception of growth, increasing temperatures generally did not enhance the toxicity of atrazine, but they did generally ameliorate the adverse effects of atrazine by accelerating development and reducing the duration of atrazine exposure. The actual effects of climate change on contaminants remains difficult to predict because temperature changes can affect chemical use, uptake, excretion, biotransformation, fate, transport, and bioavailability. However, this work highlights the importance of explicitly considering how climate change will affect both exposure and toxicity to contaminants to accurately assess risk.
Fell‐Muir Lecture: Metalloproteinases: from demolition squad to master regulators
Authors: Murphy Gillian
Published: July 2010

Two families of the Metzincin clan of metalloproteinases, the matrix metalloproteinases and the disintegrin metalloproteinases have attracted much attention as important effectors of cellular interactions with their environment. They appear to play significant roles in the modulation of components of the extracellular matrix, matrix and cell receptors, as well as the cytokines and growth factors and their receptors. Such functions at the ‘cutting edge’ of cell biology puts these enzymes in pivotal roles in the orchestration of the rapid response of cells to their environment, acting as key switches between different signalling pathways. Inevitably such enzymes should be regarded as suitable targets for therapeutic approaches to many diseases where such pathways become dysregulated. A major challenge to the development of direct inhibitors of catalysis has been the broad structural similarity of the Metzincin catalytic site. More detailed knowledge of active site structures has helped to some extent to resolve the development of more specific chemical inhibitors and selected enzymes are now being targeted. An alternative strategy is the consideration of the role of the extracatalytic domains that are determinants of specificity at a variety of levels. Dissecting the relationships between structure and function of these interaction sites is allowing the development of new approaches to inhibition of enzyme function. Antibodies are proving useful tools in this respect and may pave the way to a novel biologics approach to disease therapy.
An electron microscopical investigation of fat destabilization in ice cream
Authors: BERGER K. G. , WHITE G. W.
Published: July 2010

A limited amount of fat destabilization occurs when ice cream mix is aerated and frozen, and this emulsion breakdown imparts some desirable properties to ice cream. A method of measuring the amount of de‐emulsified fat is described, and the results of an investigation of the process by means of electron microscopy are given. The effects of fat composition and processing variables on fat destabilization are summarized, and an overall picture is presented of the part played by fat in the structure of ice cream.
Fresh beef packed in mixtures of oxygen and carbon dioxide
Authors: TAYLOR A. A. , MacDOUGALL D. B.
Published: July 2010

Fresh beef was stored in mixtures of carbon dioxide and oxygen, and measurements were made of gas exchanges and colour of the meat. Oxygen and carbon dioxide dissolved in the meat, while respiration consumed oxygen and produced more carbon dioxide. The subsequent reductions in oxygen and carbon dioxide partial pressures depended to some extent on the packaging operation and, under commercial conditions, could reach critical levels. At high oxygen partial pressures the layer of oxygenated tissue at the surface was sufficient to conceal the development of underlying metmyoglobin which causes discolouration in conventionally pre‐packaged meat. Although this layer was oxidized slowly to metmyoglobin, meat packed in 80% O2 and 20% CO2 remained attractive for at least a week at + 1°C.
Thermal diffusivities of some unfrozen and frozen food models
Authors: ALBIN F. V. , NARAYANA K. BADARI , MURTHY S. SRINIVASA , MURTHY M. V. KRISHNA
Published: July 2010

Using an experimental plate freezer, the time‐temperature histories of some food models and food products are measured during cooling in the unfrozen state and heating in the frozen state. These time‐temperature curves are matched with theoretical predictions using a nonlinear estimation technique to yield the thermal diffusivity data. Thermal diffusivities of food models of different compositions, mashed potatoes of different moisture contents and of shrimps are tabulated.
Long term storage of some dry foods: a discussion of some of the principles involved
Authors: McWeeny D. J.
Published: July 2010

Foods which have been dried to the point where microbiological growth is inhibited can still deteriorate through chemical, biochemical and physical changes. Keeping foods cool and dry is normally the best way of minimizing these changes but this is not universally the case. Some exceptions are discussed in relation to the scientific principles underlying storage practice with flour, fats, yeast, sugar and dried milk. The mechanisms involved in loss of baking quality of flour, β‐carotene deterioration in fats, loss of gassing power in yeast, syrup formation in sugar and loss of solubility in dried milk are discussed.
The effect of enzymic modification on the foaming, water absorption and baking quality of defatted soya flour
Authors: BOBALIK JULIA M. , TARANTO M. V.
Published: July 2010

Defatted soya flour slurries were treated for 0,5,10,15 and 30 min with papain at 50°C and tested for whipability, water absorption and baking quality at replacement levels in wheat flour of 10,20 and 30% (w/w). When whipped, all modified suspensions showed volume increases exceeding 250% with lower stability ratings than the unmodified samples. The 30 min enzyme treated product exhibited excellent water absorption. Use in bread resulted in a depression of loaf volume, development of a granular texture, off‐colour and flavour. As was expected, all favourable characteristics decreased upon increasing the percentage of soya product in the dough formulation. Loaf volumes of breads containing 10% modified soya flour (MSF) ranged from 444 to 527 cc; with 20% MSF between 374 and 428 cc, and with 30% MSF between 383 and 409 cc. Loaf volume of all wheat flour bread was 861cc. Hunter colour difference meter readings indicated samples at all replacement levels, regardless of the enzyme modification time, exhibited higher levels of visual lightness than all wheat flour bread. All experimental breads exhibited a higher level of yellow tones and lower level of green tones compared to the all wheat flour bread.
Biochemical and technological characteristics of hot chicken meat
Authors: KIJOWSKI J. , NIEWIAROWICZ A. , KUJAWSKA‐BIERNAT B.
Published: July 2010

In the hot breast and leg muscles of broiler chicken the level of ATP, the ‘R’ value, the lactic acid content, the pH value, the length of sarcomers, the water and fat retention capacity, the fat emulsion stability, thermal drip, and the extractability of protein fraction were investigated. It was found that in the breast muscles the onset of rigor mortis commenced within 30–60 min, and in the leg muscles as early as 15–30 min after killing of the birds. The deepest rigor mortis occurred between the first and fourth hour, and then gradually declined, sooner in the leg than in the breast muscles. The addition of sodium chloride (2.0–2.5%) to the minced pre‐rigor meat not later than 40 min after slaughter, or better, an injection of NaCl brine into intact muscles 15 min after slaughter of birds, preserved their good technological properties.

The tenderness and the thermal drip of hot salted and chilled salted muscles showed no significant differences, but water retention and fat emulsifying capacity were better in the hot salted meat samples. The hot salted and cooked muscles were preferred by the sensory panel to corresponding samples of chilled muscles.

From the hot salted chicken meat more sarcoplasmic and myofibrillar proteins were extracted than from meat salted after chilling. However, after frozen storage the extractability of myofibrillar proteins were higher in the salted chilled meat.
The microbial flora of vacuum packed smoked herring fillets
Authors: MAGNÚSSON H. , TRAUSTADÓTTIR K.
Published: July 2010

The quantitative and qualitative changes in the microbial flora of vacuum packed smoked herring fillets, held at 10°C over a period of 18 weeks, were examined. Samples were periodically tested by a sensory panel for taste and smell. Initial total counts were in the order of 104/g. After 7 weeks' storage the counts reached 108/g. No significant changes were recorded thereafter. Initially, the incidence of yeasts was high (64%). After 9 weeks of storage these were no longer detected. Homofermentative Lactobacillus sp(p). increased during the keeping period, reaching 84% of the total flora after 12 weeks' storage. Sensory data indicated a keeping quality of at least 3 months at 10°C. No correlation was observed between sensory scores and total microbial counts. It appears that total plate counts have a minor significance in quality assessment of vacuum packed smoked herring fillets.
Measurement of fat and sucrose in dry cake mixes by near infrared reflectance spectroscopy
Authors: OSBORNE B. G. , FEARN T. , RANDALL P. G.
Published: July 2010

A feasibility study was carried out to assess the potential of near infrared (NIR) reflectance spectroscopy for the measurement of fat and sucrose in dry cake mixes. The calibration of the NIR instrument was carried out in a research laboratory and then assessed under quality control conditions in the factory laboratory. It was possible to measure fat with an accuracy (±2σ) of ±3.4% for products with a fat content of 8–25% compared with +0.76% for the precision of the Soxhlet procedure. In the case of sucrose the accuracy was ±5.4% for products with a sucrose content of 10–40% compared with ±2.0% for a high pressure liquid chromatography (hplc) method. It must be concluded, therefore, that while NIR offers a quicker, simpler method of quality control, this is at the expense of accuracy.
Whipping test for the determination of foaming capacity of protein: a collaborative study
Authors: PATEL P. D. , STRIPP A. M. , FRY J. C.
Published: July 2010

A standard whipping test, which involved preparing a 0.5% protein dispersion, whipping the dispersion in a Kenwood Chef food mixer and measuring the foaming properties (foam expansion, FE; foam volume stability, FVS; foam liquid stability, FLS) was collaboratively evaluated. A total of sixty determinations was made involving six laboratories, each of which analysed five samples in duplicate. The repeatability coefficient of variation (CV0) in the estimation of FE and FVS properties of proteins was 6.25%. The reproducibility coefficient of variation (CVX) for FE and FVS was 9.8%, excluding the FE value (i.e. 20%) for spray‐dried albumen. The CV0 and CVX values for FLS properties of proteins ranged from 7.4 to 13.4% and 17.2 to 24.6%, respectively. Thus, FE, FVS and FLS properties can be used for intralaboratory comparisons (e.g. to determine batch‐to‐batch variation in commercial protein products), whereas FE and FVS values are more reliable for inter‐laboratory comparisons of the foaming properties of proteins.
Physicochemical changes of maize starch during the lime‐heat treatment for tortilla making
Authors: ROBLES R. R. , MURRAY E. D. , PAREDES‐LÓPEZ O.
Published: July 2010

As measured by the Brabender viscoamylograph, alkali‐cooking and soaking of maize in water (nixtamalization) caused large increases in viscosity, as compared with native flour. Marked effects of cooking time on the pasting properties of nixtamal were also observed. As assessed by the blue value method, nixtamalization does not cause extensive gelatinization of the starch. This was supported by differential scanning calorimetric studies, which yielded similar gelatinization endotherms for untreated maize and nixtamal flours. However, no endotherm peak appeared in tortilla samples made from this nixtamal. Furthermore, untreated maize and nixtamal flours contained many unswollen starch granules.
Use of hake (Merluccius merluccius) surimi in a Frankfurter formulation
Authors: VARELTZIS K. , ZETOU F. , SOULTOS N. , TSIARAS I.
Published: July 2010

The feasibility of using hake surimi as a partial replacement of red meat in Frankfurter‐type sausages was examined. Sensory evaluation and objective instrumental methods were used to determine textural characteristics of the finished Frankfurters. Microbiological examinations were performed throughout the 20 days storage period. Surimi formulations containing 10% hake were little different in texture, flavour, colour and acceptability from conventional red meat products.
Physical measures of sensory texture in thawed sea scallop meat
Authors: CHUNG S. L. , MERRITT J. H.
Published: July 2010

An instrumental method of texture measurement for scallop (Placopecten magellanicus) meats after frozen storage has been developed to replace the sensory method. Non‐destructive and destructive compressive forces at 50 and 80% deformation respectively and shear peak force gave significant correlation coefficients of 0.89, 0.78 and 0.82 respectively with sensory evaluation of the cooked meats. The coefficient of variation associated with the compression method was smaller, however, than with the shear method.
Changes in rheological and viscoelastic properties and protein breakdown during the ripening of ‘Port Salut Argentino’ cheese
Authors: BERTOLA N. C. , BEVILACQUA A. E. , ZARITZKY N. E.
Published: July 2010

Changes in the rheological behaviour and viscoelastic properties during ripening at 10°C of a soft cheese (Port Salut Argentino) packaged in a plastic film (EVA‐EVA) were analysed. Casein degradation was measured by electrophoresis slab gels; αs1 casein degradation was rapid and striking compared with that of β casein. Rheological parameters obtained from uniaxial compression tests changed during ripening: hardness decreased, adhesiveness and cohesiveness increased.

An exponential decay equation with two maxwellian elements and one elastic in parallel was fitted to characterize stress relaxation curves. Viscoelastic parameters (elastic moduli and relaxation times) were obtained using non‐linear regression analysis. The elastic equilibrium modulus decreased 80% during the ripening period and the viscosity of the element with the highest relaxation time decreased 20%. These parameters represented the changes observed in cheese hardness and elasticity during ageing time and were related to the extent of casein breakdown.
On‐board handling and freezing of the sea scallop, Placopecten magellanicus
Authors: CHUNG S. L. , MERRITT J. H.
Published: July 2010

The effects of on‐board handling and freezing on the quality of meats from the sea scallop, Placopecten magellanicus, in the Atlantic Canadian fishery were investigated. The results show that meats frozen within 6 h of catching, pre‐rigor, were markedly superior to meats frozen after storage in ice for up to 10 days, with lower drip loss, more tender texture, less flavour loss and higher overall acceptability.

Inferior results were obtained without pre‐chilling of the meats before storage in cotton bags in melting ice and with live holding for 3 days followed by freezing and storage at minus 30°C for up to 6 months. Days in ice before freezing, however, exerted by far the greatest influence on quality.

According to these results, freezing on board warrants consideration on grounds of superior quality including increased yield of cooked product.
Effect of ascorbic acid on the foaming and gelling of globular proteins
Authors: HOWELL NAZLIN K. , TAYLOR CLAIRE
Published: July 2010

Foam expansion and foam stability of plasma and egg albumen proteins were enhanced in the presence of increasing concentrations of ascorbic acid (0.1–1.0%). BSA showed the greatest improvement in foaming properties following treatment with ascorbic acid, whilst foaming properties of egg albumen were improved to a limited extent. A combination of partial acid hydrolysis and treatment with 1% ascorbic acid was required to dramatically improve the foaming properties of bovine blood plasma. In the presence of sucrose, foam expansion of both native and ascorbic acid‐treated blood plasma was decreased. In contrast the foam expansion of ascorbic acid‐treated egg albumen was greater although this effect decreased slightly on incubation. the gelation of ascorbic acid treated proteins increased with increasing temperatures over 80–90°C, particularly for BSA and blood plasma, and with increasing concentrations of ascorbic acid. Ascorbic acid‐treated proteins exhibited enhanced surface and exposed hydrophobicity and reduced numbers of sulphydryl groups indicating the involvement of these factors in foam and gel formation.
Transcriptional regulation of lipid homeostasis in mycobacteria
Authors: Salzman V. , Mondino S. , Sala C. , Cole S. T. , Gago G. , Gramajo H.
Published: July 2010

Mycolic acids are major components of the cell envelope of mycobacteria, such as Mycobacterium tuberculosis, and play an important role in its architecture, impermeability and interaction with the environment. Synthesis of mycolic acids is carried out by two types of fatty acid synthases (FAS) working in concert: type I FAS, a multifunctional enzyme capable of de novo synthesis of medium‐chain fatty acids, and type II FAS, responsible for their elongation. In this article we report the identification and characterization of a transcriptional regulator (MabR), whose binding to the FAS‐II promoter region was demonstrated in vitro and in vivo. Overexpression and knock‐down studies in Mycobacterium smegmatis revealed the repressor nature of MabR, with reduced amounts of FAS‐II transcripts and fatty acids in the overproducing strain. Under these conditions, downregulation of fas transcription was also observed, thereby suggesting the existence of cross‐talk between the two FAS, mediated by MabR. Finally, the finding that a mabR knock‐out mutant could only be obtained in a merodiploid strain of M. smegmatis, confirmed the predicted essentiality, thus implying an essential role for MabR in mycobacterial fatty acid metabolism.
ATP control of dynamic P1 ParA–DNA interactions: a key role for the nucleoid in plasmid partition
Authors: Vecchiarelli Anthony G. , Han Yong‐Woon , Tan Xin , Mizuuchi Michiyo , Ghirlando Rodolfo , Biertümpfel Christian , Funnell Barbara E. , Mizuuchi Kiyoshi
Published: July 2010

P1 ParA is a member of the Walker‐type family of partition ATPases involved in the segregation of plasmids and bacterial chromosomes. ATPases of this class interact with DNA non‐specifically in vitro and colocalize with the bacterial nucleoid to generate a variety of reported patterns in vivo. Here, we directly visualize ParA binding to DNA using total internal reflection fluorescence microscopy. This activity depends on, and is highly specific for ATP. DNA‐binding activity is not coupled to ATP hydrolysis. Rather, ParA undergoes a slow multi‐step conformational transition upon ATP binding, which licenses ParA to bind non‐specific DNA. The kinetics provide a time‐delay switch to allow slow cycling between the DNA binding and non‐binding forms of ParA. We propose that this time delay, combined with stimulation of ParA's ATPase activity by ParB bound to the plasmid DNA, generates an uneven distribution of the nucleoid‐associated ParA, and provides the motive force for plasmid segregation prior to cell division.
H‐NS‐mediated repression of CRISPR‐based immunity in Escherichia coli K12 can be relieved by the transcription activator LeuO
Authors: Westra Edze R. , Pul Ümit , Heidrich Nadja , Jore Matthijs M. , Lundgren Magnus , Stratmann Thomas , Wurm Reinhild , Raine Amanda , Mescher Melina , Van Heereveld Luc , Mastop Marieke , Wagner E. Gerhart H. , Schnetz Karin , Van Der Oost John , Wagner Rolf , Brouns Stan J. J.
Published: July 2010

The recently discovered prokaryotic CRISPR/Cas defence system provides immunity against viral infections and plasmid conjugation. It has been demonstrated that in Escherichia coli transcription of the Cascade genes (casABCDE) and to some extent the CRISPR array is repressed by heat‐stable nucleoid‐structuring (H‐NS) protein, a global transcriptional repressor. Here we elaborate on the control of the E. coli CRISPR/Cas system, and study the effect on CRISPR‐based anti‐viral immunity. Transformation of wild‐type E. coli K12 with CRISPR spacers that are complementary to phage Lambda does not lead to detectable protection against Lambda infection. However, when an H‐NS mutant of E. coli K12 is transformed with the same anti‐Lambda CRISPR, this does result in reduced sensitivity to phage infection. In addition, it is demonstrated that LeuO, a LysR‐type transcription factor, binds to two sites flanking the casA promoter and the H‐NS nucleation site, resulting in derepression of casABCDE12 transcription. Overexpression of LeuO in E. coli K12 containing an anti‐Lambda CRISPR leads to an enhanced protection against phage infection. This study demonstrates that in E. coli H‐NS and LeuO are antagonistic regulators of CRISPR‐based immunity.
The maltose ATP‐binding cassette transporter in the 21st century – towards a structural dynamic perspective on its mode of action
Authors: Bordignon Enrica , Grote Mathias , Schneider Erwin
Published: July 2010

The maltose/maltodextrin transport system of Escherichia coli/Salmonella, composed of periplasmic maltose‐binding protein, MalE, the pore‐forming subunits MalF and MalG, and a homodimer of the nucleotide‐binding subunit, MalK, serves as a model for canonical ATP‐binding cassette importers in general. The wealth of knowledge accumulated on the maltose transporter in more than three decades by genetic, molecular genetic and biochemical means was complemented more recently by crystal structures of the isolated MalK dimer and of two conformational states of the full transporter. Here, we summarize insights into the transport mechanism provided by these structures and draw the reader's attention to experimental tools by which the dynamics of the transporter can be studied during substrate translocation. A transport model is presented that integrates currently available biochemical, biophysical and structural data. We also present the state of knowledge on regulatory functions of the maltose transporter associated with the C‐terminal domain of MalK. Finally, we will address the application of coarse‐grained modelling to visualize the progression of the conformational changes of an ABC transporter with special emphasis on the maltose system, which can provide a model platform for testing and validating the bioinformatic tools.