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2.
JDS Commun ; 5(3): 215-219, 2024 May.
Article in English | MEDLINE | ID: mdl-38646577

ABSTRACT

Although postpartum Ca supplementation strategies are often employed to prevent subclinical hypocalcemia in dairy cows, these strategies have produced a mix of beneficial, neutral, and detrimental results when assessing milk yield and subsequent disease outcomes. Because the mechanisms underlying these differing results are unknown, our objectives were to determine how common postpartum Ca supplementation strategies affect blood Ca concentrations and parathyroid hormone (PTH). We conducted a randomized controlled trial with 74 multiparous dairy cows on a commercial dairy in central New York. Cows were assigned to 1 of 4 supplementation groups immediately after calving: (1) control (CON; no Ca supplementation, n = 15); (2) conventional oral Ca supplementation (BOL-C; 43 g of oral Ca bolus administered immediately after calving and 24 h later, n = 17); (3) delayed oral Ca supplementation (BOL-D; 43 g of oral Ca bolus administered 48 and 72 h after calving, n = 15); or (4) subcutaneous infusion (SQ; 500 mL of 23% Ca borogluconate infused subcutaneously once immediately after calving, n = 15). Blood samples were collected immediately after calving (0 h) and at 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 120, and 168 h postpartum for a total of 15 blood samples per cow. Cows were excluded if administered Ca, via any route, by farm employees or if they died or were sold within 96 h following parturition, which left 62 cows for analysis. Linear mixed models, accounting for repeated measures, were created to analyze changes in serum total Ca (tCa) and PTH over the first 168 h after parturition and assess differences between supplementation groups. Serum tCa and PTH concentrations were not different at the time of calving among supplementation groups. There was a supplementation group by hour postcalving interaction for mean tCa concentration in which SQ cows had reduced tCa concentrations from 32 to 64 h compared with CON cows, 32 to 96 h compared with BOL-C cows, and 40 to 64 h compared with BOL-D cows. Mean PTH concentration did not differ among supplementation groups across 168 h after enrollment and was 158.1 pmol/L (95% confidence interval [CI] = 148.2 to 168.0) for CON cows, 164.0 pmol/L (95% CI = 154.9 to 173.1) for BOL-C cows, 158.7 pmol/L (95% CI = 149.2 to 168.1) for BOL-D cows, and 153.2 pmol/L (95% CI = 143.6 to 162.8) for SQ cows. Our findings suggest that although serum tCa does not differ between cows that receive conventional or delayed oral Ca bolus supplementation at calving and cows that receive no supplemental Ca, subcutaneous infusion of Ca at calving reduces serum tCa for a substantial period between 32 and 64 h postsupplementation. However, as PTH concentrations did not differ among groups across 168 h postpartum, the mechanism by which tCa is reduced remains unclear.

3.
Food Res Int ; 181: 114109, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38448097

ABSTRACT

Microplastics are a complex mix of chemicals containing polymers and certain plastic additives such as bisphenols and phthalates. These particles are porous materials that can also sorb contaminants from their surroundings, and leach chemicals from the particle under certain circumstances. Aquatic animals can ingest microplastic particles, which mostly bioaccumulate in the gastrointestinal tract of animals. In terms of dietary exposure, small animals consumed whole such as mussels, contribute more to the dietary intake of microplastic particles. Plastic additives and contaminants are not chemically bound to the polymers, and certain processing methods or cooking processes result in the release of these chemicals that leach from the plastic particles, leaving them more available for absorption when ingested. Analytical methods are crucial for a better understanding of the occurrence of plastic additives and contaminants in aquatic products, and to know certain circumstances and treatments that influence human exposure. This study uses an MSPD-HPLC methodology for the simultaneous determination of 9 analytes (BPA, BPF, BPS, DEP, DBP, DEHP, DDD, DDT, and DDE) analyzing, for the first time, the occurrence of these chemicals in raw, steamed and canned mussels of two different harvesting areas (Atlantic and the Mediterranean), becoming one of the most efficient methodologies for determining the presence of these analytes in very complex food matrices, able to define the changes in cooking and processing activities. The results showed that the heat and pressure treatment could influence the migration of plastic additives from microplastic particles present in mussels to the cooking liquids.


Subject(s)
Bivalvia , Plastics , Animals , Humans , Chromatography, High Pressure Liquid , Microplastics , Seafood , Steam
4.
J Dairy Sci ; 106(10): 7117-7130, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37210366

ABSTRACT

At the onset of lactation, calcium (Ca) homeostasis is challenged. For the transitioning dairy cow, inadequate responses to this challenge may result in subclinical hypocalcemia at some point in the postpartum period. It has been proposed that dynamics of blood Ca and the timing of subclinical hypocalcemia allow cows to be classified into 4 Ca dynamic groups by assessing serum total Ca concentrations (tCa) at 1 and 4 days in milk (DIM). These differing dynamics are associated with different risks of adverse health events and suboptimal production. Our prospective cohort study aimed to characterize the temporal patterns of milk constituents in cows with differing Ca dynamics to investigate the potential of Fourier-transform infrared spectroscopic (FTIR) analysis of milk as a diagnostic tool for identifying cows with unfavorable Ca dynamics. We sampled the blood of 343 multiparous Holsteins on a single dairy in Cayuga County, New York, at 1 and 4 DIM and classified these cows into Ca dynamic groups using threshold concentrations of tCa (1 DIM: tCa <1.98 mmol/L; 4 DIM: tCa <2.22 mmol/L) derived from receiver operating characteristic curve analysis based on epidemiologically relevant health and production outcomes. We also collected proportional milk samples from each of these cows from 3 to 10 DIM for FTIR analysis of milk constituents. Through this analysis we estimated the milk constituent levels of anhydrous lactose (g/100 g of milk and g/milking), true protein (g/100 g of milk and g/milking), fat (g/100 g of milk and g/milking), milk urea nitrogen (mg/100 g of milk), fatty acid (FA) groups including de novo, mixed origin, and preformed FA measured in grams/100 g of milk, by relative percentage, and grams/milking, as well as energy-related metabolites including ketone bodies and milk-predicted blood nonesterified FA. Individual milk constituents were compared among groups at each time point and over the entire sample period using linear regression models. Overall, we found differences among the constituent profiles of Ca dynamic groups at approximately every time point and over the entire sample period. The 2 at-risk groups of cows did not differ from each other at more than one time point for any constituent, however prominent differences existed between the milk of normocalcemic cows and the milk of the other Ca dynamic groups with respect to FA. Over the entire sample period, lactose and protein yield (g/milking) were lower in the milk of at-risk cows than in the milk of the other Ca dynamic groups. In addition, milk yield per milking followed patterns consistent with previous Ca dynamic group research. Though our use of a single farm does limit the general applicability of these findings, our conclusions provide evidence that FTIR may be a useful method for discriminating between cows with different Ca dynamics at time points that may be relevant in the optimization of management or development of clinical intervention strategies.


Subject(s)
Cattle Diseases , Hypocalcemia , Female , Cattle , Animals , Humans , Milk/chemistry , Calcium , Hypocalcemia/veterinary , Prospective Studies , Cattle Diseases/metabolism , Lactation/physiology , Postpartum Period , Calcium, Dietary/analysis , Fatty Acids/analysis , Lactose/analysis
5.
J Dairy Sci ; 106(4): 2716-2728, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36823015

ABSTRACT

Cows undergo immense physiological stress to produce milk during early lactation. Monitoring early lactation milk through Fourier-transform infrared (FTIR) spectroscopy might offer an understanding of which cows transition successfully. Daily patterns of milk constituents in early lactation have yet to be reported continuously, and the study objective was to initially describe these patterns for cows of varying parity groups from 3 through 10 d postpartum, piloted on a single dairy. We enrolled 1,024 Holstein cows from a commercial dairy farm in Cayuga County, New York, in an observational study, with a total of 306 parity 1 cows, 274 parity 2 cows, and 444 parity ≥3 cows. Cows were sampled once daily, Monday through Friday, via proportional milk samplers, and milk was stored at 4°C until analysis using FTIR. Estimated constituents included anhydrous lactose, true protein, and fat (g/100 g of milk); relative % (rel%) of total fatty acids (FA) and concentration (g/100 g of milk) of de novo, mixed, and preformed FA; individual fatty acids C16:0, C18:0, and C18:1 cis-9 (g/100 g of milk); milk urea nitrogen (MUN; mg/100 g of milk); and milk acetone (mACE), milk ß-hydroxybutyrate (mBHB), and milk-predicted blood nonesterified fatty acids (mpbNEFA) (all expressed in mmol/L). Differences between parity groups were assessed using repeated-measures ANOVA. Milk yield per milking differed over time between 3 and 10 DIM and averaged 8.7, 13.3, and 13.3 kg for parity 1, 2, and ≥3 cows, respectively. Parity differences were found for % anhydrous lactose, % fat, and preformed FA (g/100 g of milk). Parity differed across DIM for % true protein, de novo FA (rel% and g/100 g of milk), mixed FA (rel% and g/100 g of milk), preformed FA rel%, C16:0, C18:0, C18:1 cis-9, MUN, mACE, mBHB, and mpbNEFA. Parity 1 cows had less true protein and greater fat percentages than parity 2 and ≥3 cows (% true protein: 3.52, 3.76, 3.81; % fat: 5.55, 4.69, 4.95, for parity 1, 2, ≥3, respectively). De novo and mixed FA rel% were reduced and preformed FA rel% were increased in primiparous compared with parity 2 and ≥3 cows. The increase in preformed FA rel% in primiparous cows agreed with milk markers of energy deficit, such that mpbNEFA, mBHB, and mACE were greatest in parity 1 cows followed by parity ≥3 cows, with parity 2 cows having the lowest concentrations. When measuring milk constituents with FTIR, these results suggest it is critical to account for parity for the majority of estimated milk constituents. We acknowledge the limitation that this study was conducted on a single farm; however, if FTIR technology is to be used as a method of identifying cows maladapted to lactation, understanding variations in early lactation milk constituents is a crucial first step in the practical adoption of this technology.


Subject(s)
Lactose , Milk , Pregnancy , Female , Cattle , Animals , Milk/chemistry , New York , Lactose/analysis , Diet/veterinary , Dietary Supplements/analysis , Lactation/physiology , Fatty Acids/analysis , Fatty Acids, Nonesterified
6.
Proc Natl Acad Sci U S A ; 119(22): e2200468119, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35613051

ABSTRACT

Aggregation of initially stably structured proteins is involved in more than 20 human amyloid diseases. Despite intense research, however, how this class of proteins assembles into amyloid fibrils remains poorly understood, principally because of the complex effects of amino acid substitutions on protein stability, solubility, and aggregation propensity. We address this question using ß2-microglobulin (ß2m) as a model system, focusing on D76N-ß2m that is involved in hereditary amyloidosis. This amino acid substitution causes the aggregation-resilient wild-type protein to become highly aggregation prone in vitro, although the mechanism by which this occurs remained elusive. Here, we identify the residues key to protecting ß2m from aggregation by coupling aggregation with antibiotic resistance in E. coli using a tripartite ß-lactamase assay (TPBLA). By performing saturation mutagenesis at three different sites (D53X-, D76X-, and D98X-ß2m) we show that residue 76 has a unique ability to drive ß2m aggregation in vivo and in vitro. Using a randomly mutated D76N-ß2m variant library, we show that all of the mutations found to improve protein behavior involve residues in a single aggregation-prone region (APR) (residues 60 to 66). Surprisingly, no correlation was found between protein stability and protein aggregation rate or yield, with several mutations in the APR decreasing aggregation without affecting stability. Together, the results demonstrate the power of the TPBLA to develop proteins that are resilient to aggregation and suggest a model for D76N-ß2m aggregation involving the formation of long-range couplings between the APR and Asn76 in a nonnative state.


Subject(s)
Amyloidosis , Protein Aggregation, Pathological , beta 2-Microglobulin , Amino Acid Substitution , Amyloidogenic Proteins/genetics , Amyloidosis/genetics , Enzyme Assays , Escherichia coli , Humans , Point Mutation , Protein Aggregation, Pathological/genetics , Protein Folding , beta 2-Microglobulin/chemistry , beta 2-Microglobulin/genetics , beta-Lactamases
8.
Food Chem ; 349: 129169, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-33548886

ABSTRACT

A new matrix solid-phase dispersion (MSPD) extraction methodology, combined with high-performance liquid chromatography equipped with a diode-array detector, was developed and validated for the simultaneous determination of 10 compounds in mussels from Galician Rias (Spain). These pollutants are compounds commonly used for plastic production as additives, as well as common plastic contaminants. The compounds selected were bisphenol-A, bisphenol-F, bisphenol-S, nonylphenol-9, nonylphenol, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethane, and dichlorodiphenyldichloroethylene. The parameters affecting the MSPD extraction efficiency such as the type of sorbent, mass sample-sorbent ratio, and extraction solvent were optimised. The proposed method provided satisfactory quantitative recoveries (80-100%), with relative standard deviations lower than 7%. In all cases, the matrix-matched calibration curves were linear in the concentration range of 0.32-120.00 µg/kg, with quantification limits of 0.25-16.20 µg/kg. The novel developed MSPD-high-performance liquid chromatography methodology provided good sensitivity, accuracy, and repeatability for quality control analysis in mussels.


Subject(s)
Bivalvia/chemistry , Endocrine Disruptors/analysis , Plastics/analysis , Solid Phase Extraction/methods , Water Pollutants, Chemical/analysis , Animals , Chromatography, High Pressure Liquid/methods , Limit of Detection , Spain
10.
BJOG ; 127(11): 1374-1380, 2020 10.
Article in English | MEDLINE | ID: mdl-32479682

ABSTRACT

OBJECTIVES: To investigate the incidence of clinical, ultrasonographic and biochemical findings related to pre-eclampsia (PE) in pregnancies with COVID-19, and to assess their accuracy to differentiate between PE and the PE-like features associated with COVID-19. DESIGN: A prospective, observational study. SETTING: Tertiary referral hospital. PARTICIPANTS: Singleton pregnancies with COVID-19 at >20+0  weeks. METHODS: Forty-two consecutive pregnancies were recruited and classified into two groups: severe and non-severe COVID-19, according to the occurrence of severe pneumonia. Uterine artery pulsatility index (UtAPI) and angiogenic factors (soluble fms-like tyrosine kinase-1/placental growth factor [sFlt-1/PlGF]) were assessed in women with suspected PE. MAIN OUTCOME MEASURES: Incidence of signs and symptoms related to PE, such as hypertension, proteinuria, thrombocytopenia, elevated liver enzymes, abnormal UtAPI and increased sFlt-1/PlGF. RESULTS: Thirty-four cases were classified as non-severe and 8 as severe COVID-19. Five (11.9%) women presented signs and symptoms of PE, all five being among the severe COVID-19 cases (62.5%). However, abnormal sFlt-1/PlGF and UtAPI could only be demonstrated in one case. One case remained pregnant after recovery from severe pneumonia and had a spontaneous resolution of the PE-like syndrome. CONCLUSIONS: Pregnant women with severe COVID-19 can develop a PE-like syndrome that might be distinguished from actual PE by sFlt-1/PlGF, LDH and UtAPI assessment. Healthcare providers should be aware of its existence and monitor pregnancies with suspected pre-eclampsia with caution. TWEETABLE ABSTRACT: This study shows that a pre-eclampsia-like syndrome could be present in some pregnancies with severe COVID-19.


Subject(s)
Coronavirus Infections/physiopathology , HELLP Syndrome/physiopathology , Placenta Growth Factor/metabolism , Pneumonia, Viral/physiopathology , Pre-Eclampsia/physiopathology , Pregnancy Complications, Infectious/physiopathology , Uterine Artery/diagnostic imaging , Vascular Endothelial Growth Factor Receptor-1/metabolism , Adult , Alanine Transaminase/metabolism , Aspartate Aminotransferases/metabolism , Betacoronavirus , Blood Pressure , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/metabolism , Female , HELLP Syndrome/etiology , HELLP Syndrome/metabolism , Humans , L-Lactate Dehydrogenase/metabolism , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/metabolism , Pre-Eclampsia/etiology , Pre-Eclampsia/metabolism , Pregnancy , Pregnancy Complications, Infectious/metabolism , Proteinuria/etiology , Proteinuria/physiopathology , Pulsatile Flow , SARS-CoV-2 , Severity of Illness Index , Tertiary Care Centers , Thrombocytopenia/etiology , Thrombocytopenia/physiopathology
11.
Int J Cosmet Sci ; 41(2): 109-117, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30994939

ABSTRACT

Cosmetic treatments aim at improving skin appearance through vehicles of good sensory properties. Those vehicles are mainly emulsions and gels designed to deliver safe and effective compounds to skin. Creams and serums are widely used to achieve these goals, but recently a new type of formulation known as organogels triggered scientific attention, particularly in the design of both topical and cosmetic formulations. It has been established that the lipophilic nature of organogels makes it an excellent candidate for the delivery of cosmetic molecules through skin. In this review, we discuss the properties and characteristics of organogels and present the advantages of the application of these systems in cosmetics.


Les traitements cosmétiques visent à améliorer l'apparence de la peau grâce à des véhicules dotés de bonnes propriétés sensorielles. Ces véhicules sont principalement des émulsions et gels conçus pour livrer des composants sûrs et efficaces à la peau. Crèmes et sérums sont largement utilisés pour atteindre ces objectifs mais un nouveau type de formulation appelé organogels a récemment attiré l'attention des scientifiques, en particulier en ce qui concerne la conception de formulations à la fois topiques et cosmétiques. Il a été établi que la nature lipophile des organogels en fait d'excellents candidats pour la livraison de molécules cosmétiques à la peau. Dans cette analyse, nous discutons des propriétés et des caractéristiques des organogels, et présentons les avantages de l'utilisation de ces systèmes dans la cosmétique.


Subject(s)
Cosmetics , Gels , Organic Chemicals/chemistry , Administration, Topical , Chemistry, Pharmaceutical , Drug Stability , Rheology , Skin Absorption
12.
J Dermatol Sci ; 2018 Apr 27.
Article in English | MEDLINE | ID: mdl-29731194

ABSTRACT

BACKGROUND: Lipoxin A4 (LXA4) is a metabolic product of arachidonic acid. Despite potent anti-inflammatory and pro-resolution activities, it remains to be determined if LXA4 has effect on ultraviolet (UV) radiation-induced skin inflammation. OBJECTIVE: To investigate the effects of systemic administration with LXA4 on UV radiation-induced inflammation and oxidative damage in the skin of mice. METHODS: Varied parameters of inflammation and oxidative stress in the skin of mice were evaluated after UV radiation (4.14 J/cm2). RESULTS: Pretreatment with LXA4 significantly inhibited UV radiation-induced skin edema and myeloperoxidase activity. LXA4 efficacy was enhanced by increasing the time of pre-treatment to up to 72 h. LXA4 reduced UV radiation-induced skin edema, neutrophil recruitment (myeloperoxidase activity and LysM-eGFP+ cells), MMP-9 activity, deposition of collagen fibers, epidermal thickness, sunburn cell counts, and production of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6 and IL-33). Depending on the time point, LXA4 increased the levels of anti-inflammatory cytokines (TGF-ß and IL-10). LXA4 significantly attenuated UV radiation-induced oxidative damage returning the oxidative status to baseline levels in parameters such as ferric reducing ability, scavenging of free radicals, GSH levels, catalase activity and superoxide anion production. LXA4 also reduced UV radiation-induced gp91phox [nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) subunit] mRNA expression and enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target enzyme nicotinamide adenine dinucleotide (phosphate) quinone oxidoreductase (Nqo1) mRNA expression. CONCLUSION: LXA4 inhibited UV radiation-induced skin inflammation by diminishing pro-inflammatory cytokine production and oxidative stress as well as inducing anti-inflammatory cytokines and Nrf2.

13.
J Med Life ; 10(3): 161-166, 2017.
Article in English | MEDLINE | ID: mdl-29075344

ABSTRACT

AIM: This study assessed the efficacy of Cerebrolysin on post-stroke spasticity, motor recovery, and global functions in an outpatient rehabilitation setting. METHODS: In this retrospective comparison study, Cerebrolysin was administered at a daily dosage of 10 ml for over 30 days as an intramuscular injection. Control patients did not receive Cerebrolysin. All the patients participated in a standardized physical and occupational rehabilitation therapy for one month at least two times per week. Efficacy was assessed at day 30 by using the Modified Ashworth Scale (MAS) for spasticity and the Manual Muscle Testing (MMT) for motor recovery. Global function was assessed by the modified Rankin Scale (mRS) at day 30. RESULTS: A total of 50 patients were eligible for participation according to the inclusion and exclusion criteria. Of these, 23 patients were treated with Cerebrolysin and 27 patients represented the control group. No significant group differences were observed at baseline. Patients treated with Cerebrolysin experienced a significant reduction of spasticity in muscles of the upper and lower limbs, whereas only minor changes were observed in the control group. In the Cerebrolysin group, differences were statistically significant at day 30. Significant improvements of muscle strength and global functions were observed in both groups at day 30. Cerebrolysin was safe and well tolerated. CONCLUSION: Cerebrolysin had a beneficial effect on post-stroke spasticity in an outpatient rehabilitation setting; intramuscular treatment for over 30 days was safe and well tolerated.


Subject(s)
Amino Acids/therapeutic use , Muscle Spasticity/complications , Muscle Spasticity/drug therapy , Stroke Rehabilitation , Stroke/complications , Stroke/drug therapy , Amino Acids/adverse effects , Demography , Female , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome
14.
Food Chem ; 224: 432-438, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28159290

ABSTRACT

The aim of this study was to prepare molecularly imprinted polymers (MIPs) with ampicillin (AMP) and to evaluate the feasibility of these materials for being used as solid phase extraction sorbent for the selective preconcentration and determination of AMP in cow milk samples. MIPs were synthesized by bulk polymerization using methacrylic acid or methyl methacrylate as monomer and ethylene glycol dimethacrylate as cross-linker at different ratios. Characterization of the MIPs were carried out by Fourier-transform infrared spectrometry. The variables affecting the molecularly imprinted solid-phase extraction (MISPE) procedure were optimized. AMP recoveries were higher than 98%, and RSD less than 7%. A preconcentration factor of 20 was reached, which was sufficient to determine AMP at levels allowed by the EU (4µgkg-1) in cow milk. The selectivity of the AMP-MIP was evaluated in presence of other structurally related ß-lactam antibiotics (amoxicillin, oxacillin, penicillin G).


Subject(s)
Ampicillin/analysis , Milk/chemistry , Molecular Imprinting/methods , Polymers/chemistry , Amoxicillin/analysis , Animals , Ethylene Glycol/chemistry , Feasibility Studies , Methacrylates/chemistry , Oxacillin/analysis , Penicillin G/analysis , Reproducibility of Results , beta-Lactams/analysis
15.
Food Chem ; 221: 721-728, 2017 Apr 15.
Article in English | MEDLINE | ID: mdl-27979264

ABSTRACT

A series of molecularly imprinted polymers (MIPs) comprising reactionary sites which are complementary to macrolide antibiotic spiramycin (SPI) were synthetized by noncovalent bulk polymerization technique. MIPs were synthesized under different polymerization process and their recognition efficiency was evaluated in binding studies in comparison with non-imprinted polymers. The best MIP was morphologically characterized and equilibrium assays were carried out. The MIP was evaluated as a sorbent for extraction and preconcentration of SPI from aqueous and sheep milk samples, and an off-line MISPE method followed by high-performance liquid chromatography with UV diode-array detection was established. Good linearity were obtained for SPI in a range of 24-965µgkg-1 and the average recoveries at three spiked levels in milk samples were higher than 90% (RSD<5%). Limit of quantification was 24.1µgkg-1. Cross-reactivity studies from other macrolides with similar structure were tested. The optimum imprinted polymer showed a good selectivity and affinity for SPI, demonstrating the potential of the proposed MISPE for rapid, sensitive and effective sample pretreatment for selective determination of SPI in sheep milk samples.


Subject(s)
Anti-Bacterial Agents/analysis , Milk/chemistry , Molecular Imprinting/methods , Polymers/chemistry , Spiramycin/analysis , Animals , Polymers/chemical synthesis , Sheep
16.
Mater Sci Eng C Mater Biol Appl ; 66: 8-15, 2016 Sep 01.
Article in English | MEDLINE | ID: mdl-27207033

ABSTRACT

The formation of hierarchical structures consisting of microstripe barriers decorated with nanorough ablated materials prepared by direct laser writing is described. Linear features of circa 25µm width and 12µm height are achieved on amorphous and crystalline titania and graphitic carbon films deposited on silicon. Ablated protrusions build up barriers decorated by nanoscale Si-film reconstructions, as indicated by EDX maps and micro-Raman spectroscopy. Wettability tests show a dramatic change in water contact angle, which leads to almost full wetting after irradiation, irrespective of the original film composition. Fluorescence microscopy images of human mesenchymal stem cells cultured on 1D and 2D structures demonstrate the short term biocompatibility of the ablated surfaces. It is shown that cells adhere, extend and polarize on feature edges, independently of the type of surface, thus suggesting that the created nanoroughness is at the origin of the antifouling behavior. In particular, irradiated anatase and graphite surfaces demonstrate an increased performance of crystalline films for the creation of cell guiding and trapping devices. The results suggest that such laser processing of films may serve as a time-and-cost-efficient method for the design of few-cells analytical surfaces.


Subject(s)
Graphite/chemistry , Silicon/chemistry , Titanium/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Adhesion/drug effects , Cells, Cultured , Humans , Lasers , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/metabolism , Microscopy, Electron, Scanning , Microscopy, Fluorescence , Spectrum Analysis, Raman , Surface Properties , Wettability
17.
Food Chem Toxicol ; 78: 26-32, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25637760

ABSTRACT

The paper describes a new and selective analytical sample treatment for quantitative extraction and preconcentration of erythromycin in presence of other macrolide antibiotics in sheep milk samples. The methodology is based on the use of a molecular imprinted polymer (MIP) employed as solid phase extraction sorbent (MISPE). The synthesized material by bulk polymerization using erythromycin (ERY) as template was evaluated as solid phase extraction sorbent, in a novel sample treatment technique that can be coupled to high-performance liquid chromatography with diode-array detector (HPLC-DAD). MIP selectivity was studied for other macrolide antibiotics with similar structures, such as tylosin (TYL), spiramycin (SPI), josamycin (JOS), roxithromycin (ROX) and ivermectin (IVER) getting recoveries for these interferents lower than 35%, for all cases except for ROX, which recoveries were around 85%. The variables affecting the molecularly imprinted solid-phase extraction (MISPE) procedure were optimized to select the best conditions of selectivity and sensitivity to determine ERY at concentration levels established by EU legislation in sheep milk. Under the selected experimental conditions, quantification limit was 24.1 µg kg(-1). Recoveries were higher than 98%, with RSDs between 0.7% and 2%. The proposed MISPE-HPLC method was validated and successfully applied to ERY analysis in sheep milk samples.


Subject(s)
Drug Residues/analysis , Erythromycin/analysis , Food Analysis/methods , Milk/chemistry , Animals , Anti-Bacterial Agents/analysis , Chromatography, High Pressure Liquid , Polymers/chemistry , Sheep, Domestic , Solid Phase Extraction
18.
Talanta ; 106: 97-103, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23598101

ABSTRACT

Analysis of chiral compounds in complex mixtures is achieved by multidimensional gas chromatography using heptakis-(2,3,6-tri-O-methyl)-ß-cyclodextrin stationary phase as the main column of the system to separate specific selected cuts containing components unresolved in the first dimension. The proposed procedure allows rapid analysis of both solid and liquid matrices by direct introduction, into the programmed temperature vaporizer (PTV) of a gas chromatograph, of either the plant material or the essential oil, respectively. A comparison between enantiomeric excesses data obtained, from plant leaves (or plant seeds) and the corresponding essential oils, by direct injection (i.e., without sample pretreatment or concentration step) into the multidimensional system is also included. Reported data demonstrate that no racemization occurs during analysis as identical enantiomeric excesses are obtained in both cases for specific chiral compounds.


Subject(s)
Chromatography, Gas/methods , Cyclohexenes/isolation & purification , Monoterpenes/isolation & purification , Oils, Volatile/chemistry , Terpenes/isolation & purification , Carum/chemistry , Cyclohexane Monoterpenes , Limonene , Mentha/chemistry , Seeds/chemistry , Stereoisomerism , beta-Cyclodextrins/chemistry
19.
Food Chem ; 135(3): 1785-8, 2012 Dec 01.
Article in English | MEDLINE | ID: mdl-22953923

ABSTRACT

Honey attributes such as geographical origin or specified botanical sources often command a premium price due to their organoleptic or pharmacoactive properties. "Miel de Granada" is a highly quality product with protected designation of origin (PDO) which includes six monofloral honeys and two multifloral honeys. Our objective was the characterization of "Miel de Granada" according to their metal content. Metal content was specific enough and allowed discrimination from honeys of different botanical and geographical origins and confirmed the authenticity of PDO labelling as Granada product with the determination of only five elements (K, Na, Ca, Mg and Zn). Chemometric techniques as cluster analysis and ANOVA were used to classify honeys according to their botanical and geographical origin in the metal data. Metal content marks the differences in honey samples and can be used as a tool to assess the quality of honeys. ANOVA showed significant differences among rosemary honeys from different geographical areas despite the botanical factor weight. Our research contributes to the groundwork studies to determine the geographical origin of Spanish honeys.


Subject(s)
Honey/analysis , Minerals/analysis , Cluster Analysis , Honey/standards , Quality Control , Spain
20.
J Food Prot ; 74(6): 960-6, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21669074

ABSTRACT

The use of on-line coupling of reversed-phase liquid chromatography and gas chromatography (RPLC-GC) with the through oven transfer adsorption desorption (TOTAD) interface and mass spectrometry (MS) was proposed for testing different types of commercial Spanish dry-cured ham for irradiation treatment at various doses (0, 1.5, 2, and 4 kGy). The qualitative analysis of radiation-specific compounds (e.g., n-pentadecane, 1-hexadecene, 1,7-hexadecadiene, n-heptadecane, 8-heptadecene, and 2-dodecylcyclobutanone) can be simultaneously established in a single run with samples that have or have not been irradiated. The overall analysis, which takes less than 100 min, includes a rapid extraction step using a small amount of dichloromethane-methanol (1:1, vol/vol) and anhydrous sodium sulfate, the subsequent fractionation of the sample in the first dimension of the system (RPLC), the transfer of the target fraction to the second dimension, the GC separation, and the MS detection. The calculated limits of detection in ham were lower than 22 ng/g. Repeatability studies provided relative standard deviation values of 0.8 to 13.5%.


Subject(s)
Chromatography, Reverse-Phase/methods , Food Irradiation , Food Preservation/methods , Mass Spectrometry/methods , Meat Products/analysis , Adsorption , Dose-Response Relationship, Radiation , Food Analysis , Food Preservation/standards
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