Proteomics analysis of human breast milk to assess breast cancer risk

Detection of breast cancer (BC) in young women is challenging because mammography, the most common tool for detecting BC, is not effective on the dense breast tissue characteristic of young women. In addition to the limited means for detecting their BC, young women face a transient increased risk of pregnancy‐associated BC. As a consequence, reproductively active women could benefit significantly from a tool that provides them with accurate risk assessment and early detection of BC. One potential method for detection of BC is biochemical monitoring of proteins and other molecules in bodily fluids such as serum, nipple aspirate, ductal lavage, tear, urine, saliva and breast milk. Of all these fluids, only breast milk provides access to a large volume of breast tissue, in the form of exfoliated epithelial cells, and to the local breast environment, in the form of molecules in the milk. Thus, analysis of breast milk is a non‐invasive method with significant potential for assessing BC risk. Here we analyzed human breast milk by mass spectrometry (MS)‐based proteomics to build a biomarker signature for early detection of BC. Ten milk samples from eight women provided five paired‐groups (cancer versus control) for analysis of dysregulatedproteins: two within woman comparisons (milk from a diseased breast versus a healthy breast of the same woman) and three across women comparisons (milk from a woman with cancer versus a woman without cancer). Despite a wide range in the time between milk donation and cancer diagnosis (cancer diagnosis occurred from 1 month before to 24 months after milk donation), the levels of some proteins differed significantly between cancer and control in several of the five comparison groups. These pilot data are supportive of the idea that molecular analysis of breast milk will identify proteins informative for early detection and accurate assessment of BC risk, and warrant further research. Data are available via ProteomeXchange with identifier PXD007066.     

Methylenetetrahydrofolate reductase polymorphism, diet, and breast cancer in Korean women

To evaluate the interactive effect of methylenetetrahydrofolate reductase (MTHFR) genotype and dietary factors on the development of breast cancer, a hospital based case-control study was conducted in South Korean study population consisting of 189 histologically confirmed incident breast cancer cases and their 189 age-matched controls without present or previous history of cancer. A PCR-RFLP method was used for the genotyping of MTHFR (C677T) and statistical evaluations were performed by unconditional logistic regression analysis. Consumption of some dietary factors, such as green vegetables (OR = 0.3, 95% CI: 0.2-0.6), white vegetables (OR = 0.3, 95% CI: 0.1-0.7) mushrooms (OR = 0.4, 95% CI: 0.3-0.7), and meats (OR = 1.7, 95% CI: 1.1-2.8) significantly decreased or increased the risk of breast cancer. Although the breast cancer risk was 1.7-fold (95% CI: 0.8-3.2) increased in women with MTHFR TT genotype, the association was not statistically significant. Women with MTHFR TT genotype and low green vegetable intake increased 5.6-fold (95% CI: 1.2-26.3) risk of breast cancer compared to high green vegetable intake group containing MTHFR CC/CT genotype. However, the interaction was not significant (p for interaction = 0.96). Our findings suggest that MTHFR polymorphism did not influence individual susceptibility to breast cancer. However MTHFR (C667T) genotype and green vegetable intakes appeared to have the interactive effect in breast cancer development.     

Comparison of inorganic films and poly(4-vinylpyridine) coatings as electrode modifiers for flow-injection systems

A glassy-carbon electrode modified with a ruthenium-containing inorganic film was used for the flow-injection determination of As(III). The linear working range was 5-100 muM, and the detection limit was 300 pg. The response was reproducible for periods of several days. A glassy-carbon electrode modified by adsorption of a quaternized poly(4-vinylpyridine) film impregnated with hexachloroiridate(II and III) was used for the oxidation of nitrite. The calibration graphs were non-linear and varied from day to day, and the peak widths were broad. Nitrite determination at a platinum electrode modified by adsorption of iodine gave results analogous to the As(III) study; however, an overlayer of quaternized poly(4-vinylpyridine) decreased the sensitivity.     

Application of azide-containing molecules as modifiers of HTPB

Journal of Thermal Analysis and Calorimetry - Hydroxyl-terminated polybutadiene (HTPB) has been widely modified and copolymerized with azide substances to be applicable as an elastomer binder in a...     

A study of three-layered latex interpenetrating polymer networks used as processing modifiers and impact modifiers of thermo-plastic resins

In this paper, the latex interpenetrating polymer network poly(n-butyl acrylate) polystyrene/poly(methyl methacrylate) (PBA/PS/PMMA, or PBSM) was synthesized by microagglomeration and three-stage emulsion polymerization. The initial poly(n-butyl acrylate) latex particle was agglomerated by methacrylic acid residue containing the polymer latex and then encapsulated by PS and PMMA. The polyblend of poly(vinyl chloride) (PVC) and PBSM (PVC/PBSM) was prepared by blending PVC and PBSM. The morphology and properties of the polyblend have been studied. Experimental results have shown that the processability and impact-resistance of PVC can be enhanced considerably by means of blending 6–20 per hundred resin (phr) PBSM. The three-layered latex interpenetrating polymer network is a promising modifier for rigid PVC (RPVC) manufactures.     

Bicellar systems as modifiers of skin lipid structure

The characterization of different bicellar aggregates and the effects of these systems on the stratum corneum (SC) microstructure have been studied. Dynamic light scattering (DLS) and freeze fracture electron microscopy (FFEM) techniques showed that both of the systems studied, dimyristoyl-phosphatidylcholine/dihexanoyl-phosphocholine (DMPC/DHPC) and dipalmitoyl-phosphocholine (DPPC)/DHPC, were formed by small discoidal aggregates at room temperature (20°C). Treating skin with DMPC/DHPC bicelles does not affect the SC lipid microstructure, whereas bicellar systems formed by DPPC and DHPC can promote the formation of new structures in the SC lipid domains. This indicates the passage of lipids from bicelles through the SC layers and also a possible interaction of these lipids with the SC lipids. Given the absence of surfactant in the bicellar composition and the small size of these structures, the use of these smart nano-systems offers great advantages over other lipid systems for dermatological purposes. Bicelles could be promising applications as drug carriers through the skin. This contribution, based on the new biological use of bicelles, may be useful to scientists engaged in colloid science and offers a new tool for different applications in skin and cosmetic research.     

Metals and coordination compounds as modifiers for epoxy resins

This review concentrates on the use of metals in the formulation of epoxy resin systems and the effect that this has on the physical and mechanical properties of the polymer system. Epoxy resins are one of the most important higher performance polymer systems in use today, ranging from simple two-part adhesives and sports equipment to high-tech applications such as formula one racing cars and the aerospace industry. Epoxy resins are capable of undergoing homopolymerisation, although this process generally yields products with inadequate properties for high-tech applications. Consequently, in many cases catalysts, additives and co-curing-agents are formulated with the epoxy resin to significantly increase the storage stability, decrease the cure time and improve the final properties. The use of metals to formulate resin systems with excellent storage stability is discussed, along with the use of coordination compounds to improve cured resin properties such as fracture toughness, thermal stability and water absorption, etc.     

Use of organosilicon compounds as modifiers of epoxy compositions

Organosilicon compounds used to improve the strength and adhesion properties, as well as the thermal stability, of epoxy compositions are reviewed. Properties of composition on the basis of bisphenol A-based ED-20 resin cured with a KrOOT-1 silicon-containing amine are described.     

Acidic peptides acting as growth modifiers of calcite crystals

Small acidic peptides comprising a repeating Phe-Asp sequence motif exert control, in vitro, on the morphology of calcite crystals similar to natural proteins from calcified tissues.     

Benzoxazine siloxanes as modifiers of epoxy resins for coatings

Coatings based on epoxy resin ED-20 modified with organosilicon 1,3-benzoxazines at a concentration of 1–10 wt % have been prepared and studied. According to the DSC data, the curing temperature of the modified compositions falls in the range of 130–150°C. It has been shown that the use of benzoxazine siloxanes as modifying additives significantly improves the adhesion and anticorrosive properties of epoxy coatings.     

Use of Langmuir-Blodgett films as modifiers for piezoresonance sensors

Films based on arachic acid, alkylated calixresorcinarenes, and β-cyclodextrin were prepared on the surfaces of piesoresonance sensors using the Langmuir-Blodgett method. A linear relationship between the frequency shift of the piesoresonance sensor and the number of monolayers was found in all of the test diphilic compounds. The Langmuir-Blodgett films were used as surface modifiers in piesoresonance sensors for the determination of nitroalkanes. The reversibility of sensor signals, that is, the complete regeneration of the films after blowing with air for 1–3 min, was an important property of the sensors. The sensing coating proposed was characterized by a long lifetime: it withstood 80–100 sorption-desorption cycles. The sensor noise level was ±20 Hz.     

Association of the XRCC1 gene polymorphisms with cancer risk in Turkish breast cancer patients

The X-ray repair cross-complementing group 1 (XRCC1) gene is believed to play an important role in base excision repair and displays genetic polymorphisms. Data on the role of XRCC1 polymorphisms in cancer susceptibility is inconsistent. In the present study, we investigated the effect of two XRCC1 polymorphisms, Arg194Trp and Arg399Gln, on breast cancer risk in a case- control study involving Turkish breast cancer patients and healthy women. Both alleles exhibited a similar distribution among cases and controls leading to lack of any significant association between the XRCC1 polymorphisms and breast cancer risk, either in homozygotes and heterozygotes or combined. The allele frequency of the codon 194 variant was very low in cases and healthy individuals (5.3 and 3.9%, respectively) compared to that of the variant 399Gln allele (39.7 and 37.4%). Our results do not support evidence for a role of the XRCC1 polymorphism in developing breast cancer.     

Effect of genetic polymorphism on the gelation of β-lactoglobulin

The rheological properties of heat-induced gels made from β-lactoglobulin variants A, B and C were compared. The relative G' values (elastic moduli) for gels formed in 90 mM NaCl solutions were A = B > C. Conversely, in 30 mM CaCl₂ the relative G' values were C > A = B. The differences in rheological properties were due to A and B variants forming less rigid gels in CaCl₂ (∼ 7 kPa) than NaCl (∼ 20 kPa), and variant C forming gels of similar rigidity in both salt solutions. It was concluded that genetic variation in β-lactoglobulin changes the effect of salts on gelation but does not cause a universal increase or decrease in gel forming ability.     

Gradient separation of pharmaceuticals employing supercritical CO2 and modifiers

Sub- and Supercritical Fluid Chromatography (SFC) were used to separate seven purine and pyrimidine-based drugs. A two-pump system was used, where one pump delivered the carbon dioxide, and the other pump delivered modifier. The modifiers used in this work were methanol, and methanol containing 0.001 M tetrabutylammonium hydroxide. Two of the compounds studied were hydrochloride salts. These compounds were analyzed by a Supercritical Fluid Extraction (SFE)/SFC method.     

Proteomics analysis of human breast milk by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) coupled with mass spectrometry to assess breast cancer risk

Breast cancer (BC) is one of the most common cancers and one of the most common causes for cancer-related mortality. Discovery of protein biomarkers associated with cancer is considered important for early diagnosis and prediction of the cancer risk. Protein biomarkers could be investigated by large-scale protein investigation or proteomics, using mass spectrometry (MS)-based techniques. Our group applies MS-based proteomics to study the protein pattern in human breast milk from women with BC and controls and investigates the alterations and dysregulations of breast milk proteins in comparison pairs of BC versus control. These dysregulated proteins might be considered potential future biomarkers of BC. Identification of potential biomarkers in breast milk may benefit young women without BC, but who could collect the milk for future assessment of BC risk. Previously we identified several dysregulated proteins in different sets of human breast milk samples from BC patients and controls using gel-based protein separation coupled with MS. Here, we performed 2D-PAGE coupled with nano-liquid chromatography–tandem MS (nanoLC-MS/MS) in a small-scale study on a set of six human breast milk pairs (three BC samples vs. three controls) and we identified several dysregulated proteins that have potential roles in cancer progression and might be considered potential BC biomarkers in the future.     

Smectic polymorphism of the 4-butyl-4-alkoxyazobenzenes and 4-pentyl-4-alkoxyazobenzenes

Two families of liquid crystalline compounds have been synthesised, the 4-butyl-4- alkoxyazobenzenes and the 4-pentyl-4-alkoxyazobenzenes; for the second family results are presented for the first time for alkoxy chains longer than butyl. The results for both families have been obtained up to the octadecyl homologues. In both families, on the basis of DSC, polarizing microscopy and thermo-optical analysis, a rich polymorphism has been detected (maximum tetramorphism). The smectic properties start with the hexyl derivative (for the butyl family) and with the heptyl derivative (for the pentyl family). Strong odd-even effects for the temperatures of clearing in both groups of compounds were detected. Our results are compared with those of de Jeu et al. and of Adomenas et al. for the 4-butyl-4- alkoxyazobenzenes, for which only one smectic modification was described.