Membrane lipid composition of Carnobacterium maltaromaticum CNCM I-3298, a highly cryoresistant lactic bacterium.

The growing consumption of fermented products has led to an increasing demand for lactic acid bacteria (LAB), especially for LAB tolerant to freezing/thawing conditions. Carnobacterium maltaromaticum is a psychrotrophic and freeze-thawing resistant lactic acid bacterium. The membrane is the primary site of damage during the cryo-preservation process and requires modulation to improve cryoresistance. However, knowledge about the membrane structure of this LAB genus is limited. We presented here the first study of the membrane lipid composition of C. maltaromaticum CNCM I-3298 including the polar heads and the fatty acid compositions of each lipid family (neutral lipids, glycolipids, phospholipids). The strain CNCM I-3298 is principally composed of glycolipids (32%) and phospholipids (55%). About 95% of glycolipids are dihexaosyldiglycerides while less than 5% are monohexaosyldiglycerides. The disaccharide chain of dihexaosyldiglycerides is composed of α-Gal(1-2)-α-Glc chain, evidenced for the first time in a LAB strain other than Lactobacillus strains. Phosphatidylglycerol is the main phospholipid (94%). All polar lipids are exceptionally rich in C18:1 (from 70% to 80%). Regarding the fatty acid composition, C. maltaromaticum CNCM I-3298 is an atypical bacterium within the genus Carnobacterium due to its high C18:1 proportion but resemble the other Carnobacterium strains as they mostly do not contain cyclic fatty acids.

Long-term survival in a stage IV small cell carcinoma of the endometrium.

•Small cell carcinoma of the endometrium is a rare malignancy with poor survival.•A patient was diagnosed with stage IV small cell carcinoma of the endometrium.•She was treated with surgery, chemotherapy (cisplatin/etoposide) and radiotherapy.•She remains disease free 5 years after completion of her treatments.

Mechanical cell disruption of Parachlorella kessleri microalgae: Impact on lipid fraction composition.

Samples of nitrogen-starved Parachlorella kessleri containing intact cells (IC), cells ground by bead milling (BM), and cells subjected to high-pressure cell disruption (HPD), together with their supernatants after centrifugation, were compared for granulometry and lipid profiles. The effects of disruption on the lipid profile and organisation were evaluated. The quantity of lipids available for extraction increased with disruption, and up to 81% could be recovered in supernatants after centrifugation, but a marked reorganization occurred. The proportion of amphiphilic free fatty acids and lysophosphatidylcholine increased during disruption due to their release or owing to lipid degradation by enzymes or physical conditions. This effect was more marked in HPD than in BM. Lipids contained in the aqueous phase, after disruption and centrifugation, were enriched in unsaturated fatty acids, BM leading to larger droplets than HPD. The larger liquid lipid droplet would be easier to recover in the following downstream processing.

[Repeated radiation dose effect and DNA repair: Importance of the individual factor and the time interval between the doses]. / Effets de répétitions de doses d'irradiation et réparation de l'ADN : importance du facteur individuel et de l'intervalle de temps entre les doses.

The dose fractionation effect is a recurrent question of radiation biology research that remains unsolved since no model predicts the clinical effect only with the cumulated dose and the radiobiology of irradiated tissues. Such an important question is differentially answered in radioprotection, radiotherapy, radiology or epidemiology. A better understanding of the molecular response to radiation makes possible today a novel approach to identify the parameters that condition the fractionation effect. Particularly, the time between doses appears to be a key factor since it will permit, or not, the repair of certain radiation-induced DNA damages whose repair rates are of the order of seconds, minutes or hours: the fractionation effect will therefore vary according to the functionality of the different repair pathways, whatever for tumor or normal tissues.

N-3 fatty acid enriched eggs and production of egg yolk powders: an increased risk of lipid oxidation?

Lipid oxidation is generally favoured by thermal processing and long-term storage. Oxidised lipids can alter nutritional and sensorial properties of foods. As eggs are widely used in food industries in dried powder form, our aim was to determine whether compositional or processing parameters have an impact on lipid oxidation from the shell eggs up to the dried powders and subsequent storage. Two batches of shell eggs were processed: one issued from hens fed with a standard diet and another receiving a diet enriched in extruded linseed, rich in linolenic acid. The extent of lipid oxidation was evaluated by quantification of conjugated dienes (CD) and malondialdehyde (MDA), but also by assessment of tocopherols, lutein and zeaxanthin losses. Results highlighted the remarkable oxidative stability of control and enriched yolk powders as revealed by a moderate increase of the quantities of CD and MDA, the lack of oxidised cholesterol and small loss of α-tocopherol.

Stability of reference proteins in human placenta: general protein stains are the benchmark.

The stability of reference proteins in semi-quantitative Western blot experiments in normal and diseased placenta has never been studied. This study aims to determine the stability of five reference proteins and two general protein stains in placentas from preeclampsia, gestational diabetes mellitus and matched control pregnancies. The stability of the reference proteins was analysed using indicators of inter-group (P value) and intra-group (coefficient of variation) stability. The effect of different normalization strategies was determined by normalizing serotonin transporter (SERT) expression against the different reference protein markers. Results show significant expression variability of ß-actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine phosphoribosyltransferase 1 (HPRT1), peptidylprolyl isomerase A (PPIA) and α-tubulin, and that amido black staining is the most stable reference protein marker. Furthermore, results show that SERT expression significantly differs according to the reference protein markers used for its normalization. The present study demonstrated the importance of using stable reference protein markers and normalization strategy in order to get correct results in semi-quantitative Western blot experiments in placental tissues.

[Radiation biology: major advances and perspectives for radiotherapy]. / Biologie des radiations: avancées majeures et perspectives pour la radiothérapie.

At the beginning of the 21st century, radiation biology is at a major turning point in its history. It must meet the expectations of the radiation oncologists, radiologists and the general public, but its purpose remains the same: to understand the molecular, cellular and tissue levels of lethal and carcinogenic effects of ionizing radiation in order to better protect healthy tissues and to develop treatments more effective against tumours. Four major aspects of radiobiology that marked this decade will be discussed: technological developments, the importance of signalling and repair of radiation-induced deoxyribonucleic acid (DNA) damage, the impact of individual factor in the response to radiation and the contribution of radiobiology to better choose innovative therapies such as protontherapy or stereotactic body radiation therapy (SBRT). A translational radiobiology should emerge with the help of radiotherapists and radiation physicists and by facilitating access to the new radio and/or chemotherapy modalities.

Direct inhibition of excision/synthesis DNA repair activities by cadmium: analysis on dedicated biochips.

The well established toxicity of cadmium and cadmium compounds results from their additive effects on several key cellular processes, including DNA repair. Mammalian cells have evolved several biochemical pathways to repair DNA lesions and maintain genomic integrity. By interfering with the homeostasis of redox metals and antioxidant systems, cadmium promotes the development of an intracellular environment that results in oxidative DNA damage which can be mutagenic if unrepaired. Small base lesions are recognised by specialized glycosylases and excised from the DNA molecule. The resulting abasic sites are incised, and the correct sequences restored by DNA polymerases using the opposite strands as template. Bulky lesions are recognised by a different set of proteins and excised from DNA as part of an oligonucleotide. As in base repair, the resulting gaps are filled by DNA polymerases using the opposite strands as template. Thus, these two repair pathways consist in excision of the lesion followed by DNA synthesis. In this study, we analysed in vitro the direct effects of cadmium exposure on the functionality of base and nucleotide DNA repair pathways. To this end, we used recently described dedicated microarrays that allow the parallel monitoring in cell extracts of the repair activities directed against several model base and/or nucleotide lesions. Both base and nucleotide excision/repair pathways are inhibited by CdCl2, with different sensitivities. The inhibitory effects of cadmium affect mainly the recognition and excision stages of these processes. Furthermore, our data indicate that the repair activities directed against different damaged bases also exhibit distinct sensitivities, and the direct comparison of cadmium effects on the excision of uracile in different sequences even allows us to propose a hierarchy of cadmium sensibility within the glycosylases removing U from DNA. These results indicate that, in our experimental conditions, cadmium is a very potent DNA repair poison.

Lipid traits of muscles as related to genotype and fattening diet in Iberian pigs: total intramuscular lipids and triacylglycerols.

Thirty pigs were allotted into four groups according to the fattening diet ("Montanera", diet= acorns and pasture; and "Pienso", diet=concentrated diet) and genotype (Iberian and Iberian×Duroc pigs). Lipid, fatty acid and triacylglycerol compositions,were measured in Biceps femoris muscle. Fattening diet largely affected muscle lipid composition. Total intramuscular lipid and triacylglycerol contents were higher in Montanera pigs than in Pienso pigs (8.0-8.1% vs 6.0-6.8% and 7.4-7.3% vs 6.2-5.4%, respectively). In Montanera pigs, triacylglycerols contained more oleic acid (54.7-56.8% vs 53.5-53.8% and less stearic and palmitic acids (8.8-8.4% vs 9.4-10.2% and 22.2-23.3 vs 23.7-24.4% respectively) and accordingly less PSO and more POL, POO and OOO(†) triacylglycerols compared to Pienso pigs (13.1-13.6% vs 16.2-19.2%, 4.4-3.5% vs 3.0-2.7%, 53.1% vs 51.3-51.9% and 10.1-12.3% vs 8.3-8.6%, respectively). Genotype had no effect on lipid and triacylglycerol contents of muscles and showed only a slight effect on fatty acid and triacylglycerol compositions.

N-Aryl sulfonyl homocysteine hydroxamate inhibitors of matrix metalloproteinases: further probing of the S(1), S(1)', and S(2)' pockets.

A series of N-arylsulfonyl S-alkyl homocysteine hydroxamic acids were synthesized with variations in three subsites corresponding to P(1), P(1)', and P(2)'. Enzyme assays with a variety of MMPs revealed activity at the low nanomolar level.

Molecular determinants of the human antibody response to HIV-1: implications for disease control.

Various aspects of the immune response to HIV-1 infection remain unclear. While seropositive subjects generally mount a strong humoral response, the antibodies produced are not effective in halting disease progression. Molecular characterization of the antibody repertoire specific for HIV-1 antigens represents an approach to further our understanding of the mechanisms involved in mounting a humoral immunity in this infection. Recently, the content, structure, and organization of the human immunoglobulin-variable gene loci have been elucidated and a number of laboratories have characterized the variable gene elements of human anti-HIV-1 antibodies derived from infected persons by cell fusion or by Epstein-Barr virus transformation. The results show evidence for extensive somatic mutations that lead to preferential amino acid substitutions in the hypervariable regions, an indication of an antigen-driven process. Multiple other molecular events also are engaged in generating antibody diversity, including various types of fusions of variable genes, usage of inverted diversity genes, and addition of extragenomic nucleotides. Most importantly, there is a paucity of antibodies expressing the major V(H)3 gene family, which could result from the capacity of gp120 to act as superantigen for human B cells. This V(H)3+ antibody deficit also has been observed in B cells isolated ex vivo from the patients. Since V(H)3+ antibodies play an essential role in immune defense against infections, the abnormalities observed in HIV-1 infection may predispose to opportunistic infections and further compromise the immune defense mechanisms of the subjects.

Urinary 1-hydroxypyrene as a biomarker of exposure to polycyclic aromatic hydrocarbons: biological monitoring strategies and methodology for determining biological exposure indices for various work environments.

This article reviews the published studies on urinary 1-hydroxypyrene (1-OHP) as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) in work environments. Sampling and analysis strategies as well as a methodology for determining biological exposure indices (BEIs) of 1-OHP in urine for different work environments are proposed for the biological monitoring of occupational exposure to PAHs. Owing to the kinetics of absorption of pyrene by different exposure routes and excretion of 1-OHP in urine, in general, 1-OHP urinary excretion levels increase during the course of a workday, reaching maximum values 3-9 h after the end of work. When the contribution of dermal exposure is important, post-shift 1-OHP excretion can however be lower than pre-shift levels in the case where a worker has been exposed occupationally to PAHs on the day prior to sampling. In addition, 1-OHP excretion levels in either pre-shift, post-shift or evening samples increase during the course of a work-week, levelling off after three consecutive days of work. Consequently, ideally, for a first characterization of a work environment and for an indication of the major exposure route, considering a 5-day work-week (Monday to Friday), the best sampling strategy would be to collect all micturitions over 24 h starting on Monday morning. Alternatively, collection of pre-shift, post-shift and evening urine samples on the first day of the work-week and at the end of the work-week is recommended. For routine monitoring, pre-shift samples on Monday and post-shift samples on Friday should be collected when pulmonary exposure is the main route of exposure. On the other hand, pre-shift samples on Monday and Friday should be collected when the contribution of skin uptake is important. The difference between beginning and end of work-week excretion will give an indication of the average exposure over the workweek. Pre-shift samples on the first day of the work-week will indicate background values, and, hence, reflect general environment exposure and body burden of pyrene and/or its metabolites. On the other hand, since PAH profile can vary substantially in different work sites, a single BEI cannot apply to all workplaces. A simple equation was therefore developed to establish BEIs for workers exposed to PAHs in different work environments by using a BEI already established for a given work environment and by introducing a correction factor corresponding to the ratio of the airborne concentration of the sum of benzo(a)pyrene (BaP) equivalent to that of pyrene. The sum of BaP equivalent concentrations represents the sum of carcinogenic PAH concentrations expressed as BaP using toxic equivalent factors. Based on a previously estimated BEI of 2.3 µmol 1-OHP mol(-1) creatinine for coke-oven workers, BEIs of 4.4, 8.0 and 9.8 µmol 1-OHP mol(-1) creatinine were respectively calculated for vertical pin Söderberg workers, anode workers and pre-bake workers of aluminium plants and a BEI of 1.2 µmol 1-OHP mol(-1) creatinine was estimated for iron foundry workers. This approach will allow the potential risk of cancer in individuals occupationally exposed to PAHs to be assessed better.

Effect of dietary fat and vitamin E on colour stability and on lipid and protein oxidation in Turkey meat during storage.

The objectives of the study were to investigate the effects of dietary fat (6% soya oil or rapeseed oil or tallow), together with tocopheryl acetate at either a basal (30 ppm) or a supplemented (400 ppm) level for 16 weeks on lipid and protein oxidation, including myoglobin, during refrigerated storage of turkey muscles. When turkeys were fed tallow in particular, vitamin E supplementation improved the vitamin E status of the muscles. Vitamin E supplementation significantly delayed lipid oxidation measured by TBARS, whatever the dietary fat. TBARS were highest in meat from animals fed soya oil. Vitamin E supplementation had no positive effect on colour stability of meat during refrigerated storage. Feeding soya oil induced significantly higher oxidation of proteins (carbonyl content) than rapeseed oil or tallow and vitamin E supplementation induced a slight decrease in carbonyl content at day 9 of storage for M. sartorius. SH content was significantly higher in vitamin E supplemented M. sartorius and M. pectoralis than in controls.

Lipid composition of adipose tissue and muscle in pigs with an increasing proportion of Meishan genes.

The purpose of this study was to estimate the effect of the proportion of Meishan (MS) genes upon the lipid composition of longissimus dorsi and trapezius muscles and perirenal and s.c. dorsal adipose tissues. Five groups of 11-15 pigs with 0, 12·5, 25, 37·5 and 50% MS genes were made up from a large herd of crossbred animals (0-100% MS dams × Piétrain sires). Results showed that: (1) the i.m. lipid content was higher in 1 2 MS than in controls and 1 4 MS pigs. Differences in the fatty acid composition of i.m. lipids, as related to genotype, depended more particularly on muscle fatness as the fatty acid compositions of triglycerides and phospholipids were little affected by the genotype. (2) The weight of perirenal and s.c. dorsal adipose tissues increased with the proportion of MS genes. Differences in the chemical composition of the adipose tissues were not related to the proportion of MS genes. The fatty acid composition was little affected by the genotype. Although the levels of polyunsaturated fatty acids decreased with increasing proportion of MS genes, these small variations had no marked influence on adipose tissue quality.

Isolation and characterization of the O-glycan chain of the human vitamin-D binding protein.

On a highly purified preparation, the structure of the carbohydrate chain of the human vitamin D-binding protein was investigated and two genetic forms of this protein were considered (Gc 2 and Gc 1 proteins). It was found that only the Gc 1 protein (Gc1a isoform) was glycosylated, the glycan moiety representing about 1% of the protein. The structure of this O-glycosidically linked glycan was determined to be: Neu Ac alpha (2 leads to 3) Gal beta (1 leads to 3) GaINAc alpha (1 leads to 0) Ser (or Thr). A tetrasaccharidic O-glycan with two N-acetylneuraminic residues was also characterized. The vitamin D-binding protein is a rare example of a serum protein O-glycosylated only on some genetic forms.

The effect of serum vitamin D-binding protein on polymerization and depolymerization of actin is similar to the effect of profilin on actin.

The mechanism of the interaction between two genetically determined serum vitamin D-binding protein forms and the muscle skeletal actin was investigated. Vitamin D-binding protein was isolated in a good yield from human serum, using immunoaffinity chromatography. 16 mg of pure vitamin D-binding protein were obtained from 100 ml of serum. The interaction between purified vitamin D-binding protein and skeletal muscle actin was studied by viscosity, delta A (232 nm) measurements and by electron microscopy. The effect of vitamin D-binding protein on actin polymerization is characterized by the decrease of the nucleation and elongation rates and by the decrease of the final concentration of polymerized actin in the steady state. The depolymerizing effect is not the result of direct action on vitamin D-binding protein on F-actin but rather of an increased concentration of the complex of the former protein with G-actin. The characteristics of the vitamin D-binding protein and profilin interactions with actin are similar. Both proteins seem to react only with G-actin.

Ectopic calcification as a late sequela of compartment syndrome. Report of two cases.

Ectopic calcification occurred in two patients as a late sequela of compartment syndrome. The clinical and roentgenographic appearance are sufficiently typical that the diagnosis should be made without difficulty. Leaving the wound open after incision and drainage of these lesions may lead to secondary infection. Closing the wound after decompression over suction drainage or needle decompression are treatment alternatives that may lead to more satisfactory results.

Unusual sialilation of the serum DBP associated with the Gc 1 allele in alcoholic cirrhosis of the liver.

The serum level of the 'vitamin D binding protein' (DBP) or Gc ('group-specific component'), its phenotype distribution and the quantitative estimation of the different electrophoretic isoforms were determined in a sample of healthy individuals (blood donors) and in patients with alcoholic hepatitis. It is shown that the serum DBP levels and the amount of the different electrophoretic isoforms are influenced by the protein phenotypes. In the patients an increased frequency of the Gc 1 allele is noticed. For the first time, an unusual form of the apo DBP protein was detected but only in the sera of the Gc 1 allele carriers. The protein form investigated by analytical procedures presents one more sialic acid residue than the usual Gc 1 protein. This unusual metabolic transformation of the DBP is mostly observed among male patients and is often associated with a deteriorating clinical outcome.