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3.
Colorectal Dis ; 24(10): 1216-1226, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35470953

RESUMO

AIM: The COLO-COHORT study aims to produce a multi-factorial risk prediction model for colorectal neoplasia that can be used to target colonoscopy to those at greatest risk of colorectal neoplasia, ensuring that people are not investigated unnecessarily and maximizing the use of limited endoscopy resources. The study will also explore the link between neoplasia and the human gut microbiome. Additionally, the study aims to generate a cohort of colonoscopy patients who are 'research ready' through the development of a consent-for-contact (C4C) platform, to facilitate a range of colorectal cancer prevention studies to be conducted at scale and speed. METHODS AND ANALYSIS: This is a multi-centre observational study involving sites across the UK. Recruitment is over a 6-year period (2019-2025). Patients recruited to the study are those attending for colonoscopy. Patients are recruited into two groups, namely observational group A (10 000 patients) and C4C group B (10 000 patients), known as COLO-SPEED (Colorectal Cancer Screening Prevention Endoscopy and Early Diagnosis; https://colospeed.uk). Patients complete a health questionnaire, provide anthropometric measurements and submit biosamples (blood and stool-depending on the part of the study they are recruited into). Patients' colonoscopy and histology findings are also recorded. Models of factors associated with the presence of neoplasia at colonoscopy will be developed using logistic or multinomial regression. For internal validation, model discrimination and calibration will be assessed and bootstrapping and cross-validation approaches used. To enable long-term follow-up for outcomes related to colorectal cancer and polyps, patients are asked to consent to follow-up through data linkage with national databases. DISSEMINATION: In keeping with good research practice, following analysis by the study team the study investigators will make the anonymized dataset available to other researchers. The C4C platform will also be accessible to other researchers. The study findings will be submitted for publication in peer-reviewed journals and lay summaries will be disseminated to participants and the wider public.


Assuntos
Colonoscopia , Neoplasias Colorretais , Humanos , Estudos de Coortes , Detecção Precoce de Câncer/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/patologia , Consentimento Livre e Esclarecido , Sangue Oculto , Estudos Observacionais como Assunto , Estudos Multicêntricos como Assunto
4.
Inquiry ; 58: 469580211030217, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34271831

RESUMO

Bladder cancer (BC) is the 10th most common malignancy worldwide and the patient experience is found to be worse than that for patients diagnosed with other cancer types. We aimed to develop a wellbeing intervention to help improve the bladder cancer patient experience by ameliorating their health-related Quality of Life (HRQoL). We followed the 3 phases of the modified Medical Research Council (MRC) Framework for development of complex interventions. Following a systematic review of the literature on mental, sexual, and physical wellbeing, we conducted discussion groups with patients and healthcare professionals on these 3 themes. A consultation phase was then conducted with all relevant stakeholders to co-design a wellbeing intervention as part of a feasibility study. A pragmatic wellbeing feasibility trial was designed based on the hypothesis that a wellbeing program will increase patient awareness and attendance to services available to them and will better support their needs to improve HRQoL. The primary feasibility endpoints are patient attendance to the services offered and changes in HRQoL. The principle of patient centered care has strengthened the commitment to provide a holistic approach to support BC patients. In this study, we developed a wellbeing intervention in collaboration with patients and healthcare professionals to meet an unmet need in terms of the BC patient experience.


Assuntos
Qualidade de Vida , Neoplasias da Bexiga Urinária , Estudos de Viabilidade , Pessoal de Saúde , Humanos , Avaliação de Resultados da Assistência ao Paciente , Neoplasias da Bexiga Urinária/terapia
5.
Eur Urol ; 79(5): 621-632, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33581875

RESUMO

BACKGROUND: Little is known about health-related quality of life (HRQOL) following treatment for bladder cancer (BC). OBJECTIVE: To determine this, we undertook a cross-sectional survey covering 10% of the English population. DESIGN, SETTING, AND PARTICIPANTS: Participants 1-10 yr from diagnosis were identified through national cancer registration data. INTERVENTION: A postal survey was administered containing generic HRQOL and BC-specific outcome measures. Findings were compared with those of the general population and other pelvic cancer patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Generic HRQOL was measured using five-level EQ-5D (EQ-5D-5L) and European Organization for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ)-C30. BC-specific outcomes were derived from EORTC QLQ-BLM30 and EORTC QLQ-NMIBC24. RESULTS AND LIMITATIONS: A total of 1796 surveys were completed (response rate 55%), including 868 (48%) patients with non-muscle-invasive BC, 893 (50%) patients who received radiotherapy or radical cystectomy, and 35 (1.9%) patients for whom treatment was unknown. Most (69%) of the participants reported at least one problem in any EQ-5D dimension. Age/sex-adjusted generic HRQOL outcomes were similar across all stages and treatment groups, whilst problems increased with age (problems in one or more EQ-5D dimensions: <65 yr [67% {95% confidence interval or CI: 61-74}] vs 85+ yr [84% {95% CI: 81-89}], p = 0.016) and long-term conditions (no conditions [53% {95% CI: 48-58}] vs more than four conditions [94% {95% CI: 90-97}], p < 0.001). Sexual problems were reported commonly in men, increasing with younger age and radical treatment. Younger participants (under 65 yr) reported more financial difficulties (mean score 20 [95% CI: 16-25]) than those aged 85+ yr (6.8 [4.5-9.2], p < 0.001). HRQOL for BC patients (for comparison, males with problems in one or more EQ-5D dimensions 69% [95% CI: 66-72]) was significantly worse than what has been found after colorectal and prostate cancers and in the general population (51% [95% CI: 48-53], all p < 0.05). CONCLUSIONS: HRQOL following BC appears to be relatively independent of disease stage, treatment, and multimodal care. Issues are reported with sexual function and financial toxicity. HRQOL after BC is worse than that after other pelvic cancers. PATIENT SUMMARY: Patients living with bladder cancer often have reduced quality of life, which may be worse than that for other common pelvic cancer patients. Age and other illnesses appear to be more important in determining this quality of life than the treatments received. Many men complain of sexual problems. Younger patients have financial worries.


Assuntos
Neoplasias Pélvicas , Neoplasias da Bexiga Urinária , Estudos Transversais , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Doenças Raras , Inquéritos e Questionários , Neoplasias da Bexiga Urinária/terapia
6.
Crit Rev Food Sci Nutr ; 61(14): 2411-2443, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32649226

RESUMO

Milk fat is a high-value milk component that is processed mainly as butter, cheese, cream and whole milk powder. It is projected that approximately 35 million tonnes of milk fat will be produced globally by 2025. This surplus, enhances the need for diversification of milk fat products and the milk pool in general. Infant milk formula producers, for instance, have incorporated enzyme modified ("humanised") milk fat and fat globule phospholipids to better mimic human milk fat structures. Minor components like mono- and di-glycerides from milk fat are increasingly utilized as emulsifiers, replacing palm esters in premium-priced food products. This review examines the chemistry of milk fat and the technologies employed for its modification, fractionation and enrichment. Emerging processing technologies such as ultrasound, high pressure processing, supercritical fluid extraction and fractionation, can be employed to improve the nutritional and functional attributes of milk fat. The potential of recent developments in biological intervention, through dietary manipulation of milk fatty acid profiles in cattle also offers significant promise. Finally, this review provides evidence to help redress the imbalance in reported associations between milk fat consumption and human health, and elucidates the health benefits associated with consumption of milk fat and dairy products.


Assuntos
Manteiga , Queijo , Animais , Bovinos , Ácidos Graxos , Fórmulas Infantis , Leite Humano
8.
Soc Sci Med ; 265: 113496, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33189426

RESUMO

OBJECTIVES: Colorectal cancer (CRC) is a leading cause of cancer death worldwide, although effective uptake of bowel cancer screening is below 60% in England. This trial investigated the influence of volitional and motivational interventions and their combination on increasing guaiac fecal occult blood testing (gFOBT) screening uptake. METHOD: In total, 34,633 participants were recruited (via North-East of England bowel cancer screening hub) into a 2×2 factorial cluster randomized controlled trial. Social norm-based motivational intervention (SNA); Implementation intention-based Volitional Help Sheet (VHS); Combined intervention (SNA+VHS); Treatment as usual control. Screening rate (gFOBT kit return rate within 8 weeks of invitation) was the primary outcome. RESULTS: Screening kits were returned by 60% of participants (N=20,847/34,633). A substantial imbalance was observed in participant characteristics, participants in the combined intervention group were younger and more likely to be first time invitees. Adjusted analyses found insufficient evidence that any of the interventions were different to control (Combined: OR = 1.18, 95% CI 0.97-1.44; SNA alone: OR=0.93; 95% CI: 0.76-1.15; VHS alone OR= 0.88; 95% CI: 0.75-1.03). Subgroup analyses demonstrated a significant beneficial effect of the combined intervention in the youngest age group compared to control (OR = 1.27; 95% CI: 1.05-1.54). CONCLUSIONS: The study did not support any benefit of either VHS or SNA interventions alone on bowel cancer screening uptake. The combined SNA+VHS intervention was significantly different from control only in the youngest age group in adjusted analyses. However, the magnitude of effect in the youngest age group suggests that further testing of VHS plus SNA interventions in carefully targeted populations may be warranted.


Assuntos
Neoplasias Colorretais , Detecção Precoce de Câncer , Neoplasias Colorretais/diagnóstico , Inglaterra , Guaiaco , Humanos , Programas de Rastreamento , Sangue Oculto
9.
Foods ; 9(3)2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32138150

RESUMO

When this Special Issue was launched, we cast the net widely in terms of the subject matter we considered suitable for the papers. We stated that papers on "well-established unit operations such as heat treatments and membrane separation in addition to emerging technologies" would be welcomed. The seven papers accepted do, indeed, cover a range of topics including UHT milk, proteolytic digestion, membrane technologies, cheese and yogurt. Three papers [...].

10.
Foods ; 8(9)2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31455046

RESUMO

Tryptic hydrolysis of whey protein isolate under specific incubation conditions including a relatively high enzyme:substrate (E:S) ratio of 1:10 is known to preferentially hydrolyse ß-lactoglobulin (ß-LG), while retaining the other major whey protein fraction, i.e., α-lactalbumin (α-LA) mainly intact. An objective of the present work was to explore the effects of reducing E:S (1:10, 1:30, 1:50, 1:100) on the selective hydrolysis of ß-LG by trypsin at pH 8.5 and 25 °C in a 5% (w/v) WPI solution during incubation periods ranging from 1 to 7 h. In addition, the use of a pilot-scale continuous high-temperature, short-time (HTST) heat exchanger with an extended holding time (EHT) of 5 min as a means of inactivating trypsin to terminate hydrolysis was compared with laboratory-based acidification to 90% ß-LG hydrolysis after respective incubation periods of 4 and 6 h, with <5% hydrolysis of α-LA in the case of 1:50. Continuous HTST-EHT treatment was shown to be an effective inactivation process allowing for the maintenance of substrate selectivity. However, HTST-EHT heating resulted in protein aggregation, which negatively impacts the downstream recovery of intact α-LA. An optimum E:S was determined to be 1:50, with an incubation time ranging from 3 h to 7 h leading to 90% ß-LG hydrolysis and minimal degradation of α-LA. Alternative batch heating by means of a water bath to inactivate trypsin caused considerable digestion of α-LA, while acidification to

11.
Food Chem ; 288: 306-314, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902298

RESUMO

Health benefits are routinely attributed to whey proteins, their hydrolysates and peptides based on in vitro chemical and cellular assays. The objective of this study was to track the fate of whey proteins through the upper gastrointestinal tract, their uptake across the intestinal barrier and then assess the physiological impact to downstream target cells. Simulated gastrointestinal digestion (SGID) released a selection of whey peptides some of which were transported across a Caco-2/HT-29 intestinal barrier, inhibited free radical formation in muscle and liver cells. In addition, SGID of ß-lactoglobulin resulted in the highest concentration of free amino acids (176 nM) arriving on the basolateral side of the co-culture with notable levels of branched chain and sulphur-containing amino acids. In vitro results indicate that consumption of whey proteins will deliver bioactive peptides to target cells.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Proteínas do Soro do Leite/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico , Células CACO-2 , Bovinos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Trato Gastrointestinal/metabolismo , Células HT29 , Humanos , Lactoglobulinas/metabolismo , Leite/metabolismo , Peptídeos/isolamento & purificação , Peptídeos/metabolismo
12.
J Nutr ; 149(1): 88-97, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30608606

RESUMO

Background: Dietary modifications can contribute to improved pancreatic ß cell function and enhance glycemic control. Objectives: The objectives of this study were as follows: 1) to investigate the potential of milk protein hydrolysates to modulate postprandial glucose response; 2) to assess individual responses; and 3) to explore the inter- and intraindividual reproducibility of the response. Methods: A 14-d randomized crossover study investigated interstitial glucose levels of participants in response to 12% w/v milk protein drinks (intact caseinate and casein hydrolysate A and B) consumed in random order with a 2-d washout between treatments. Milk protein drinks were consumed immediately prior to study breakfast and evening meals. Twenty participants (11 men, 9 women) aged 50 ± 8 y with a body mass index (in kg/m2) of 30.2 ± 3.1 were recruited. Primary outcome was glucose levels assessed at 15-min intervals with the use of glucose monitors. Results: Repeated-measures ANOVA revealed that for breakfast there was a significant difference across the 3 treatment groups (P = 0.037). The ability to reduce postprandial glucose was specific to casein hydrolysate B in comparison with intact caseinate (P = 0.039). However, despite this significant difference, further examination revealed that only 3 out of 18 individuals were classified as responders (P < 0.05). High intraclass correlation coefficients were obtained for glucose response to study meals (intraclass correlation coefficient: 0.892 for breakfast with intact caseinate). The interindividual CVs were higher than the intraindividual CVs. Mean inter- and intraindividual CVs were 19.4% and 5.7%, respectively, for breakfast with intact caseinate. Conclusion: Ingestion of a specific casein hydrolysate successfully reduced the postprandial glucose response; however, at an individual level only 3 participants were classified as responders, highlighting the need for precision nutrition. Exploration of high interindividual responses to nutrition interventions is needed, in combination with the development of precision nutrition, potentially through an n-of-1 approach. This clinical trial was registered as ISRCTN61079365 (https://www.isrctn.com/).


Assuntos
Glicemia/efeitos dos fármacos , Proteínas do Leite/farmacologia , Terapia Nutricional , Sobrepeso , Medicina de Precisão , Adulto , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Leite/administração & dosagem
13.
J Dairy Sci ; 102(1): 54-67, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30527978

RESUMO

Oxidative stress caused by free radicals has been implicated in several human disorders. Dietary antioxidants can help the body to counteract those reactive species and reduce oxidative stress. Antioxidant activity is one of the multiple health-promoting attributes assigned to bovine whey products. The present study investigated whether this activity was retained during upper gut transit using a static simulated in vitro gastrointestinal digestion (SGID) model. The capacity to scavenge free radicals and reduce ferric ion of whey protein isolate (WPI), individual whey proteins, and hydrolysates pre- and post-SGID were measured and compared using various antioxidant assays. In addition, the free AA released from individual protein fractions in physiological gut conditions were characterized. Our results indicated that the antioxidant activity of WPI after exposure to the harsh conditions of the upper gut significantly increased compared with intact WPI. From an antioxidant bioactivity viewpoint, this exposure negates the need for prior hydrolysis of WPI. The whey protein α-lactalbumin showed the highest antioxidant properties post-SGID (oxygen radical absorbance capacity = 1,825.94 ± 50.21 µmol of Trolox equivalents/g of powder) of the 4 major whey proteins tested with the release of the highest amount of the antioxidant AA tryptophan, 6.955 µmol of tryptophan/g of protein. Therefore, α-lactalbumin should be the preferred whey protein in food formulations to boost antioxidant defenses.


Assuntos
Antioxidantes/metabolismo , Trato Gastrointestinal/metabolismo , Proteínas do Soro do Leite/metabolismo , Animais , Antioxidantes/administração & dosagem , Bromelaínas/metabolismo , Bovinos , Cromanos/administração & dosagem , Cromanos/metabolismo , Digestão , Sequestradores de Radicais Livres/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Lactalbumina/metabolismo , Metaloendopeptidases/metabolismo , Proteínas do Leite/metabolismo , Estresse Oxidativo , Subtilisinas/metabolismo , Soro do Leite/química , Proteínas do Soro do Leite/administração & dosagem
14.
J Dairy Sci ; 101(12): 10750-10758, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30268616

RESUMO

Our previous study identified peaks in the 31P nuclear magnetic resonance (31P NMR) spectra of skim milk, denoting the interaction of different phosphate species such as inorganic and casein-associated phosphate during the separation of colloidal and serum phases of skim milk by microfiltration (MF) and diafiltration (DF). In the current study, we investigated the same samples generated by the aforementioned separation using attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy analysis. The results confirmed that the technique was not only capable of differentiating between the mineral equilibrium of the casein phosphate nanocluster (CPN) and milk serum, but also complemented the application of 31P NMR. An ATR-FTIR broad band in the region of 1,055 to 1,036 cm-1 and a specific band at 1,076 cm-1 were identified as sensitive to the repartitioning of different phosphate species in milk in accordance with the 31P NMR signals representing casein-associated phosphate and inorganic phosphate in the serum. A third ATR-FTIR signal at 1,034 cm-1 in milk, representing precipitated inorganic calcium phosphate, had not previously been detected by 31P NMR. Thus, the results indicate that a combination of ATR-FTIR and 31P NMR spectroscopies may be optimally used to follow mineral and protein phase changes in milk during membrane processing.


Assuntos
Caseínas/análise , Filtração/métodos , Espectroscopia de Ressonância Magnética/métodos , Leite/química , Fosfatos/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Animais , Caseínas/química , Manipulação de Alimentos/métodos , Fosfatos/química , Isótopos de Fósforo
15.
Int J Mol Sci ; 19(9)2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30223587

RESUMO

Recent times have seen an increasing move towards harnessing the health-promoting benefits of food and dietary constituents while providing scientific evidence to substantiate their claims. In particular, the potential for bioactive protein hydrolysates and peptides to enhance health in conjunction with conventional pharmaceutical therapy is being investigated. Dairy-derived proteins have been shown to contain bioactive peptide sequences with various purported health benefits, with effects ranging from the digestive system to cardiovascular circulation, the immune system and the central nervous system. Interestingly, the ability of dairy proteins to modulate metabolism and appetite has recently been reported. The ghrelin receptor (GHSR-1a) is a G-protein coupled receptor which plays a key role in the regulation of food intake. Pharmacological manipulation of the growth hormone secretagogue receptor-type 1a (GHSR-1a) receptor has therefore received a lot of attention as a strategy to combat disorders of appetite and body weight, including age-related malnutrition and the progressive muscle wasting syndrome known as cachexia. In this study, a milk protein-derivative is shown to increase GHSR-1a-mediated intracellular calcium signalling in a concentration-dependent manner in vitro. Significant increases in calcium mobilisation were also observed in a cultured neuronal cell line heterologously expressing the GHS-R1a. In addition, both additive and synergistic effects were observed following co-exposure of GHSR-1a to both the hydrolysate and ghrelin. Subsequent in vivo studies monitored standard chow intake in healthy male and female Sprague-Dawley rats after dosing with the casein hydrolysate (CasHyd). Furthermore, the provision of gastro-protected oral delivery to the bioactive in vivo may aid in the progression of in vitro efficacy to in vivo functionality. In summary, this study reports a ghrelin-stimulating bioactive peptide mixture (CasHyd) with potent effects in vitro. It also provides novel and valuable translational data supporting the potential role of CasHyd as an appetite-enhancing bioactive. Further mechanistic studies are required in order to confirm efficacy as a ghrelinergic bioactive in susceptible population groups.


Assuntos
Caseínas/metabolismo , Ingestão de Alimentos , Expressão Gênica , Receptores de Grelina/genética , Animais , Cálcio/metabolismo , Caseínas/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Ativação Enzimática , Estabilidade Enzimática , Feminino , Grelina/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Imagem Molecular/métodos , Ratos , Receptores de Grelina/metabolismo
16.
J Dairy Sci ; 101(6): 4747-4761, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29605324

RESUMO

Oxidative stress contributes to cell injury and aggravates several chronic diseases. Dietary antioxidants help the body to fight against free radicals and, therefore, avoid or reduce oxidative stress. Recently, proteins from milk whey liquid have been described as antioxidants. This review summarizes the evidence that whey products exhibit radical scavenging activity and reducing power. It examines the processing and treatment attempts to increase the antioxidant bioactivity and identifies 1 enzyme, subtilisin, which consistently produces the most potent whey fractions. The review compares whey from different milk sources and puts whey proteins in the context of other known food antioxidants. However, for efficacy, the antioxidant activity of whey proteins must not only survive processing, but also upper gut transit and arrival in the bloodstream, if whey products are to promote antioxidant levels in target organs. Studies reveal that direct cell exposure to whey samples increases intracellular antioxidants such as glutathione. However, the physiological relevance of these in vitro assays is questionable, and evidence is conflicting from dietary intervention trials, with both rats and humans, that whey products can boost cellular antioxidant biomarkers.


Assuntos
Antioxidantes/farmacologia , Proteínas do Soro do Leite/farmacologia , Animais , Antioxidantes/química , Glutationa/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Proteínas do Soro do Leite/química
17.
J Dairy Sci ; 100(9): 6949-6961, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28690057

RESUMO

Membrane separation processes used in the concentration and isolation of micellar casein-based milk proteins from skim milk rely on extensive permeation of its soluble serum constituents, especially lactose and minerals. Whereas extensive literature exists on how these processes influence the gross composition of milk proteins, we have little understanding of the effects of such ionic depletion on the core structural unit of micellar casein [i.e., the casein phosphate nanocluster (CPN)]. The 31P nuclear magnetic resonance (NMR) is an analytical technique that is capable of identifying soluble and organic forms of phosphate in milk. Thus, our objective was to investigate changes to the 31P NMR spectra of skim milk during microfiltration (MF) and diafiltration (DF) by tracking movements in different species of phosphate. In particular, we examined the peak at 1.11 ppm corresponding to inorganic phosphate in the serum, as well as the low-intensity broad signal between 1.5 and 3.0 ppm attributed to casein-associated phosphate in the retentate. The MF concentration and DF using water caused a shift in the relevant 31P NMR peak that could be minimized if orthophosphate was added to the DF water. However, this did not resolve the simultaneous change in retentate pH and increased solubilization of micellar casein protein. The addition of calcium in combination with orthophosphate prevented micellar casein solubilization and simultaneously contributed to preservation of the CPN structure, except for overcorrection of retentate pH in the acidic direction. A more complex DF solution, involving a combination of phosphate, calcium, and citrate, succeeded in both CPN and micellar casein structure preservation while maintaining retentate pH in the region of the original milk pH. The combination of 31P NMR as an analytical technique and experimental probe during MF/DF processes provided useful insights into changes occurring to CPN while retaining the micellar state of casein.


Assuntos
Caseínas/química , Micelas , Proteínas do Leite/química , Leite/química , Animais , Filtração , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética/métodos , Concentração Osmolar , Fósforo/química
18.
Nutr Cancer ; 68(7): 1234-46, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27472445

RESUMO

Buttermilk is a rich source of milk fat globule membrane (MFGM) fragments assembled from bioactive polar lipids and proteins that originate from bovine mammary epithelial cells. The objective of this study was to examine growth-modulatory effects of experimental buttermilks varying in sphingolipid and phospholipid composition on a colon cancer cell line of human origin. Buttermilks were prepared from washed and unwashed cream using gravity or centrifugation. Compositional analysis showed that sphingomyelin (SM) (10.4-29.5%) and lactosylceramide (LacCer) (1.2-44.3%) were the predominant sphingolipids detected. Experimental samples inhibited in vitro growth of SW480 colon cancer cells in a dose-dependent manner. Antiproliferative activity was selective toward cancer cells. A fraction enriched in LacCer (44.3%), obtained by microfiltration induced caspase-independent cell death as evident by phosphatidylserine externalization, increased percentage of degraded DNA, and loss of mitochondrial membrane potential in SW480 cells. This fraction downregulated growth-signaling pathways mediated by ß-catenin, phosphorylated Akt (serine/threonine-specific protein kinase), ERK1/2 (extracellular signal-regulated kinase), and c-myc. This study is to our knowledge the first to screen buttermilk samples that vary in polar lipid composition for antiproliferative activity in vitro.


Assuntos
Leitelho , Neoplasias do Colo/prevenção & controle , Regulação para Baixo , Alimento Funcional , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Via de Sinalização Wnt , Leitelho/análise , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Indústria de Laticínios , Manipulação de Alimentos , Alimento Funcional/análise , Humanos , Potencial da Membrana Mitocondrial , Fosfolipídeos/análise , Fosfolipídeos/metabolismo , Fosforilação , Projetos Piloto , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-akt/metabolismo , Esfingolipídeos/análise , Esfingolipídeos/metabolismo
19.
Food Chem ; 199: 409-15, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26775989

RESUMO

Enzymatic hydrolysis of a commercial whey protein isolate (WPI) using either trypsin or Protamex® was compared using controlled (pH-stat) and uncontrolled (free-fall) pH conditions. pH-stat control at the enzyme's optimum value led to a more rapid rate of WPI hydrolysis by trypsin, while the opposite was the case when Protamex® was used. Furthermore, the choice of alkaline solution used to maintain constant pH during pH-stat experiments appeared to affect the reaction rate, being higher when KOH is added to the reaction mixture instead of NaOH. It would appear that potassium may play a role as co-factor or activator for the activity of this particular protease preparation. Although pH-stat techniques are usually considered to yield better hydrolysis kinetics, these findings suggest that the response of proteolytic enzyme preparations to static or free-fall pH control should be checked in advance, particularly when undertaking large scale production of WPI hydrolysates.


Assuntos
Proteínas do Soro do Leite/química , Hidrólise
20.
J Agric Food Chem ; 63(10): 2708-14, 2015 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-25716093

RESUMO

The ferrous (Fe2+) chelating capabilities of WPI hydrolysate fractions produced via cascade membrane filtration were investigated, specifically 1 kDa permeate (P) and 30 kDa retentate (R) fractions. The 1 kDa-P possessed a Fe2+ chelating capability at 1 g L(-1) equivalent to 84.4 µM EDTA (for 30 kDa-R the value was 8.7 µM EDTA). Fourier transformed infrared (FTIR) spectroscopy was utilized to investigate the structural characteristics of hydrolysates and molecular interactions with Fe2+. Solid-phase extraction was employed to enrich for chelating activity; the most potent chelating fraction was enriched in histidine and lysine. The solubility of ferrous sulfate solutions (10 mM) over a range of pH values was significantly (P<0.05) improved in dispersions of hydrolysate fraction solutions (10 g protein L(-1)). Total iron solubility was improved by 72% in the presence of the 1 kDa-P fraction following simulated gastrointestinal digestion (SGID) compared to control FeSO4·7H2O solutions.


Assuntos
Ferro/química , Proteínas do Leite/química , Quelantes/química , Digestão , Compostos Ferrosos/química , Humanos , Ferro/metabolismo , Proteínas do Leite/metabolismo , Modelos Biológicos , Hidrolisados de Proteína/química , Hidrolisados de Proteína/metabolismo , Solubilidade , Proteínas do Soro do Leite
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