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1.
J Dairy Sci ; 102(2): 1768-1774, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30580948

RESUMEN

After parturition, the start of copious milk production in dairy cows requires the closure of tight junctions (TJ) to form the blood-milk barrier and prevent paracellular transfer of blood constituents into milk [e.g., lactate dehydrogenase (LDH) and serum albumin (SA)] and vice versa [e.g., appearance of α-lactalbumin (α-LA) in blood]. Serotonin (5-HT) has been demonstrated to alter tight junction permeability in the mammary gland. The present study investigated individual differences of TJ permeability of mammary epithelium at the beginning of lactation in relation to circulating 5-HT in dairy cows. Blood and milk samples were obtained from 11 multiparous Holstein dairy cows for the first time at 4 h after parturition, at the following 5 milkings, and at the evening milkings on d 5, 8, 10, and 14 of lactation. Retrospectively, cows were split into 2 groups according to their calculated areas under the curve of serum 5-HT during the entire experimental period: a high-serum 5-HT (HSS) group (5 cows) and a low-serum 5-HT (LSS) group (6 cows). The areas under the curve of serum 5-HT concentrations over the 324-h experimental period were 62 ± 2 × 103 ng/mL in HSS and 25 ± 5 × 103 ng/mL in LSS. Plasma α-LA concentration was greater in LSS than in HSS cows at the first milking, but no difference between groups was found from the second to sixth milking. Yield of α-LA in milk was lower in HSS than in LSS during the first 6 milkings postpartum, especially in colostrum. Concentrations of α-LA, IgG1, and IgG2 in milk did not differ between groups during the entire experiment except for higher IgG observed in LSS than in HSS at the second milking and for higher IgG2 found in HSS compared with LSS on d 5. In contrast, SA concentrations and LDH activity in milk were lower in LSS compared with HSS cows during the first 6 milkings postpartum, particularly in colostrum. Milk somatic cell count was higher in HSS than in LSS throughout the study. Higher circulating 5-HT concentrations were associated with an increased transfer of the paracellularly transported SA, LDH, and somatic cell count, especially at the first milking, suggesting that 5-HT affects TJ permeability during closure of the blood-milk barrier at the onset of lactation. Furthermore, higher serum 5-HT concentrations were associated with a lower α-LA yield in milk. A consistent relationship with serum 5-HT concentrations was neither observed for the transfer of IgG2 nor the primarily transcellular transport of IgG1 during the first milkings after parturition.


Asunto(s)
Bovinos/sangre , Serotonina/sangre , Uniones Estrechas/metabolismo , Animales , Bovinos/fisiología , Parto Obstétrico , Femenino , Inmunoglobulina G/sangre , Lactalbúmina/sangre , Lactancia/sangre , Leche/metabolismo , Parto , Permeabilidad , Periodo Posparto , Embarazo , Estudios Retrospectivos , Albúmina Sérica/metabolismo
2.
Mikrochim Acta ; 185(10): 449, 2018 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-30194494

RESUMEN

The authors describe a method for electrochemical determination of the breast cancer biomarker α-lactalbumin (α-LA) using disposable screen-printed carbon electrodes (SPCEs). Lysozyme-conjugated Fe3O4 nanoparticles (Lys-Fe3O4NPs) were used to capture α-LA on the surface of the SPCEs which then is trapped in an immunosandwich using secondary antibodies labeled with ferrocene-modified gold nanoparticles. The amperometric response of ferrocene (recorded at +0.1 V vs. silver pseudo-reference electrode) as well as the electrocatalytic activity of gold nanoparticles on the hydrogen evolution reaction (recorded at -1.0 V Vs Ag pseudo-reference electrode) was exploited to sense α-LA. A sensitive voltammetric response is observed, with (a) a sensitivity of 0.8789 µA·nM-1.cm-2, (b) a detection limit (LOD, at S/N = 3) as low as 0.07 ng·mL-1, and (c) linear response in the 0.75 to 630 ng mL-1 α-LA concentration range. The assay is selective and reproducible, and the SPCEs have good storage stability. The SPCEs were applied (a) to the analysis of (spiked) maternal milk, (b) of spiked serum from healthy and pregnant persons, and (c) of serum of patients suffering from breast cancer. Graphical abstract Schematic presentation of a sensitive electrochemical immunoassay platform based on ferrocene modified gold nanoparticles and lysozyme modified magnetic beads for the determination of alpha lactalbumin in human sera and breast milk by the amperometric response of ferrocene and hydrogen evolution reaction.


Asunto(s)
Compuestos Ferrosos/química , Oro/química , Inmunoensayo/métodos , Lactalbúmina/análisis , Nanopartículas de Magnetita/química , Metalocenos/química , Microesferas , Muramidasa/química , Electroquímica , Humanos , Lactalbúmina/sangre , Límite de Detección , Modelos Moleculares , Muramidasa/metabolismo , Conformación Proteica
3.
J Sci Food Agric ; 97(8): 2516-2523, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27711962

RESUMEN

BACKGROUND: The effect of a diet containing 15% grape pomace (GP) on the general health status and milk quality of dairy cows was assessed by plasma biochemistry and total polyphenol (TP) content, milk polyphenols, milk composition and milk protein fractions. RESULTS: Among the polyphenols measured by liquid chromatography-mass spectroscopy in GP, in feed containing GP (GP+) or not containing GP (GP-), gallic acid and epicatechin were present in the highest concentrations (67.58 and 19.23 µg mL-1 , respectively). Higher amounts of TP were also detected in the blood plasma of GP+ cows (114.06 and 83.93 mg GAE L-1 , respectively) but not in their milk (233.17 and 245.75 mg GAE L-1 , respectively). Also a significant increase was found for lactose and ß-lactoglobulin, although there was no effect on α-lactalbumin, albumin, secretory components and caseins. CONCLUSION: Inclusion of 15% GP in the diets of dairy cows is beneficial for overall normal blood constituent metabolism and helps to maintain cow health. The milk of cows fed with a GP diet preserves the normal levels of fat, protein and caseins, and has increased levels of components that make this milk a versatile ingredient material for the food industry (e.g. model whey powders, stability of lactose-rich powders). © 2016 Society of Chemical Industry.


Asunto(s)
Alimentación Animal/análisis , Alimentación Animal/envenenamiento , Bovinos/sangre , Suplementos Dietéticos/análisis , Leche/química , Polifenoles/sangre , Vitis/química , Residuos/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Catequina/sangre , Bovinos/metabolismo , Femenino , Ácido Gálico/sangre , Lactalbúmina/sangre , Lactancia , Lactoglobulinas/sangre , Leche/metabolismo , Vitis/metabolismo
4.
Allergy ; 70(8): 955-62, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25951431

RESUMEN

BACKGROUND: A new treatment option for persistent cow's milk allergy (CMA) is oral immunotherapy (OIT). Not all patients develop tolerance during therapy, and markers to identify those who will benefit from it are needed. The objective was to study the IgE and IgG4 antibody profiles to milk and milk proteins before and after OIT in relation to clinical outcome. METHODS: Seventy-six children (5-17 years) with challenge-verified CMA were subjected to a 6-month OIT protocol. The treatment aimed at reaching a maintenance dose of 200 ml CM (high dose = HD). Those who did not reach target were analysed as a low-dose (LD) group. Sera were characterized before and after OIT regarding serum levels of IgE and IgG4 to milk and five milk allergen components evaluated together with clinical CMA symptoms and outcome of OIT. RESULTS: Fifty-five (72%) patients reached the maintenance dose (HD) during therapy. High specific IgE levels towards the milk allergens α-lactalbumin (P = 0.048), ß-lactoglobulin (P = 0.006) and casein (P = 0.015) before OIT start were associated with lower maintenance dose reached. Patients who developed desensitization had a larger increase in IgG4 levels to α-lactalbumin (P = 0.034), ß-lactoglobulin (P = 0.010), casein (P = 0.047) and lactoferrin (P = 0.030) during treatment than those who failed. CONCLUSIONS: Component-resolved diagnostics before OIT can help to identify children with lower probability of a successful OIT outcome, as high IgE levels to α-lactalbumin, ß-lactoglobulin and casein are associated with lower maintenance dose reached. An increase in the IgG4 concentration to milk components during treatment indicated effective desensitization.


Asunto(s)
Caseínas/sangre , Inmunoglobulina E/sangre , Inmunoterapia/métodos , Lactalbúmina/sangre , Hipersensibilidad a la Leche/sangre , Hipersensibilidad a la Leche/terapia , Administración Oral , Adolescente , Animales , Biomarcadores/sangre , Caseínas/inmunología , Bovinos , Niño , Preescolar , Estudios de Cohortes , Desensibilización Inmunológica/métodos , Femenino , Estudios de Seguimiento , Humanos , Lactalbúmina/inmunología , Masculino , Leche/efectos adversos , Leche/inmunología , Hipersensibilidad a la Leche/diagnóstico , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Estadísticas no Paramétricas , Resultado del Tratamiento
5.
J Dairy Sci ; 98(11): 7748-56, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26298756

RESUMEN

Colostrum has a different composition compared with milk in established lactation. This difference is in part due to the partially open blood-milk barrier, which, when closed, is designed to prevent the interdiffusion of blood and milk components. In the first days of lactation, α-lactalbumin (α-LA), a milk protein, is typically present in blood and several blood-derived proteins are also present in milk, such as IgG1, IgG2, serum albumin (SA), and lactate dehydrogenase (LDH). With the exception of IgG1, which is known to be transferred by active transcellular transport, the other proteins are thought to pass paracellularly through the temporarily open barrier. Along with an exchange of blood and milk components, somatic cell count (SCC) is typically high in colostrum. The decline of these proteins and SCC can be used as indicators to determine transcellular or paracellular transport. Two hypotheses were tested. The first hypothesis was that the decline curve for a protein or SCC would be the same as IgG1, indicating transcellular transport, or the decline curve would be different than IgG1, indicating paracellular transport. The second hypothesis was that the decline curves of SCC and all proteins that are thought to have paracellular transport would be the same. Ten Holstein cows were milked at 4 h after parturition, the next 5 consecutive milkings, and the afternoon milking on d 5, 8, 10, and 14 of lactation for a total of 10 milking time points, and sequential jugular blood samples were also taken. Blood and milk samples were analyzed for the concentrations of LDH, SA, IgG1, IgG2, and α-LA and milk samples were measured for SCC. Protein concentration and SCC curves were generated from all 10 time points and were evaluated using the tau time constant model to determine the rate of decline of the slope of each protein. When examining the first hypothesis, the concentration of IgG1 declined significantly faster in the milk than the proteins IgG2 and LDH, but declined at the same rate as SA. Immunoglobulin G1 also declined significantly faster than SCC and α-LA in plasma. The second hypothesis showed that IgG2, LDH, and SA in milk were declining at the same rate, but were declining significantly faster than SCC and α-LA in plasma. These results indicate that only active transcellular transport of IgG1 occurred, with a sharp decline at parturition, compared with IgG2, SA, LDH, α-LA, and SCC, which are likely following paracellular transport.


Asunto(s)
Inmunoglobulina G/análisis , L-Lactato Deshidrogenasa/análisis , Lactancia , Leche/química , Albúmina Sérica/análisis , Animales , Bovinos , Recuento de Células/veterinaria , Calostro/química , Femenino , Inmunoglobulina G/sangre , L-Lactato Deshidrogenasa/sangre , Lactalbúmina/análisis , Lactalbúmina/sangre , Modelos Biológicos , Suiza
6.
J Dairy Res ; 82(3): 322-7, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26137855

RESUMEN

This study aimed to describe chronological patterns of changes of various candidate blood components in milk during the acute phase of a mammary immune response in detail. Eight dairy cows were challenged with Escherichia coli lipopolysaccharide in one udder quarter. Milk from challenged and control quarters and blood samples were taken before, and 1 and 2 h after challenge and then every 15 min until 5 h after challenge. The SCC, serum albumin, immunoglobulin (Ig)G1, IgG2, lactate dehydrogenase (LDH), and L-lactate in milk and blood, and α-lactalbumin in blood were analysed. All selected parameters in milk increased in challenged quarters but did not increase in control quarters. Milk IgG1, IgG2, serum albumin, and LDH were already significantly increased at 2 h after challenge whereas a significant increase of SCC was detectable at 2.75 h and L-lactate was increased at 2.25 h after challenge. In blood L-lactate was increased at 3.75 h after challenge, however, other factors in blood did not change significantly within the 5 h of experiment. In conclusion, the increase of blood components in milk during inflammation follows two different patterns: There is a rapid increase for IgG1, IgG2, or LDH, before the increase of SCC, and their concentrations reach a plateau within 3 h. On the other hand, SCC and L-lactate show a slower but consistent increase not reaching a plateau within 5 h after LPS challenge. L-lactate increases to higher concentrations in milk than in blood. This clearly shows that the increase of blood components follows different patterns and is therefore a controlled and compound-specific process and not exclusively an unspecific type of leakage.


Asunto(s)
Mastitis Bovina/sangre , Mastitis Bovina/metabolismo , Leche/química , Reacción de Fase Aguda/sangre , Reacción de Fase Aguda/metabolismo , Animales , Bovinos , Recuento de Células , Escherichia coli , Femenino , Inmunoglobulina G/análisis , Inmunoglobulina G/sangre , L-Lactato Deshidrogenasa/análisis , L-Lactato Deshidrogenasa/sangre , Lactalbúmina/sangre , Ácido Láctico/análisis , Ácido Láctico/sangre , Lipopolisacáridos/administración & dosificación , Glándulas Mamarias Animales/efectos de los fármacos , Glándulas Mamarias Animales/inmunología , Leche/citología , Albúmina Sérica/análisis , Factores de Tiempo
7.
Science ; 190(4211): 276-8, 1975 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-1179206

RESUMEN

A sensitive and specific radioimmunoassay for human alpha-lactalbumin, a major milk protein, is described. Some normal men and women have detectable levels of alpha-lactalbumin in their blood. High values are found in nursing mothers and many patients with galactorrhea. Alpha-Lactalbumin is found in some breast cancer organ cultures. In addition, alpha-lactalbumin output was stimulated by ovine prolactin in 2 of the 19 tumors studied.


Asunto(s)
Neoplasias de la Mama/análisis , Lactalbúmina/análisis , Adolescente , Adulto , Anciano , Neoplasias de la Mama/sangre , Carcinoma/análisis , Carcinoma/sangre , Niño , Femenino , Galactorrea/sangre , Humanos , Lactalbúmina/sangre , Lactancia , Masculino , Persona de Mediana Edad , Técnicas de Cultivo de Órganos , Embarazo , Prolactina/fisiología
8.
Psychopharmacology (Berl) ; 201(1): 107-14, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18648776

RESUMEN

RATIONALE: Reduced brain serotonin function is acknowledged as a vulnerability factor for affective disturbances. Since the production of serotonin is limited by the availability of its plasma dietary amino acid precursor tryptophan (TRP), the beneficial effects of tryptophan-rich alpha-lactalbumin whey protein (ALAC) have recently been studied. The effects of ALAC remain rather modest, and alternative protein sources of tryptophan may be more effective. OBJECTIVES: We tested whether hydrolyzed protein (HPROT) has greater effects on the plasma TRP/large neutral amino acids (LNAA) ratio and mood than intact ALAC protein in healthy volunteers. MATERIALS AND METHODS: In a double-blind, randomized cross-over study, plasma amino acids and mood were repeatedly measured in 18 healthy subjects before and after intake of ALAC and HPROT as well as after placebo protein, pure tryptophan, and a tryptophan-containing synthetic peptide. Except for the placebo protein, all interventions contained 0.8 g TRP. RESULTS: Significantly faster and greater increases in plasma TRP/LNAA were found after HPROT than after ALAC. In addition, the effects of HPROT on plasma TRP/LNAA were comparable with the effects of the tryptophan-containing synthetic peptide and even exceeded the effect of pure tryptophan. Sixty minutes after intake, mood was improved only following intake of HPROT and pure tryptophan, whereas longer-lasting mood effects were only found after intake of HPROT. CONCLUSIONS: The use of a tryptophan-rich hydrolyzed protein source may be more adequate to increase brain tryptophan and 5-HT function compared with intact alpha-lactalbumin protein or pure tryptophan.


Asunto(s)
Afecto/efectos de los fármacos , Aminoácidos Neutros/farmacología , Disponibilidad Biológica , Encéfalo/efectos de los fármacos , Triptófano/farmacología , Administración Oral , Adolescente , Adulto , Aminoácidos Neutros/sangre , Aminoácidos Neutros/clasificación , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Método Doble Ciego , Esquema de Medicación , Femenino , Predicción , Humanos , Hidrólisis , Lactalbúmina/administración & dosificación , Lactalbúmina/sangre , Lactalbúmina/química , Masculino , Proteínas de la Leche/administración & dosificación , Proteínas de la Leche/química , Proteínas de la Leche/metabolismo , Péptidos/administración & dosificación , Péptidos/síntesis química , Péptidos/química , Placebos , Plasma/química , Plasma/efectos de los fármacos , Triptófano/sangre , Proteína de Suero de Leche , Adulto Joven
9.
Food Funct ; 9(11): 5805-5812, 2018 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-30352111

RESUMEN

The effects of casein non-phosphopeptide (CNPP) on the muscle development of healthy rats and selected blood hormones levels were investigated. CT technology and the ELISA kit were employed to detect the cross-sectional area of each muscle group and blood hormone levels, respectively. The cross-sectional area of the trunk and lower limb muscles of resistance exercise group (REG) rats that were administered a high daily dose of CNPP for 50 days increased more significantly than that of the blank group rats, no exercise group (NEG) rats administered with the same daily dose of CNPP, and REG rats administered with the same daily dose of lactalbumin (P < 0.05).The more enhanced development of trunk and lower limb muscles in CNPP-administered REG rats was associated with a higher blood level of insulin, while no clear trends in blood levels of growth hormone and testosterone were observed. The present results have demonstrated that a combination of physical exercise and diet supplementation with CNPP can synergistically improve muscle mass.


Asunto(s)
Caseínas/farmacología , Músculo Esquelético/efectos de los fármacos , Condicionamiento Físico Animal , Tomógrafos Computarizados por Rayos X , Animales , Hormona del Crecimiento/sangre , Concentración de Iones de Hidrógeno , Insulina/sangre , Lactalbúmina/sangre , Leucina/farmacología , Masculino , Desarrollo de Músculos/efectos de los fármacos , Músculo Esquelético/crecimiento & desarrollo , Ratas , Ratas Wistar , Testosterona/sangre
10.
Am J Clin Nutr ; 105(2): 379-390, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28052887

RESUMEN

BACKGROUND: Holder pasteurization has been reported to modify human milk composition and structure by inactivating bile salt-stimulated lipase (BSSL) and partially denaturing some of its proteins, potentially affecting its subsequent digestion. OBJECTIVE: We sought to determine the impact of human milk pasteurization on gastric digestion (particularly for proteins and lipids) in preterm infants who were fed their mothers' own milk either raw or pasteurized. DESIGN: In a randomized controlled trial, 12 hospitalized tube-fed preterm infants were their own control group in comparing the gastric digestion of raw human milk (RHM) with pasteurized human milk (PHM). Over a 6-d sequence, gastric aspirates were collected 2 times/d before and after RHM or PHM ingestion. The impact of milk pasteurization digestive kinetics and disintegration was tested with the use of a general linear mixed model. RESULTS: Despite inactivating BSSL, instantaneous lipolysis was not affected by pasteurization (mean ± SD at 90 min: 12.6% ± 4.7%; P > 0.05). Lipolysis occurred in milk before digestion and was higher for PHM than for RHM (mean ± SD: 3.2% ± 0.6% and 2.2% ± 0.8%, respectively; P < 0.001). Pasteurization enhanced the proteolysis of lactoferrin (P < 0.01) and reduced that of α-lactalbumin (only at 90 min) (P < 0.05). Strong emulsion destabilization was observed, with smaller aggregates and a higher specific surface for PHM (P < 0.05). Pasteurization did not affect gastric emptying (∼30-min half time) or pH (mean ± SD: 4.4 ± 0.8) at 90 min. CONCLUSIONS: Overall, pasteurization had no impact on the gastric digestion of lipids and some proteins from human milk but did affect lactoferrin and α-lactalbumin proteolysis and emulsion disintegration. Freeze-thawing and pasteurization increased the milk lipolysis before digestion but did not affect gastric lipolysis. Possible consequences on intestinal digestion and associated nutritional outcomes were not considered in this study. This trial was registered at clinicaltrials.gov as NCT02112331.


Asunto(s)
Digestión , Leche Humana/química , Pasteurización , Caseínas/sangre , Carbohidratos de la Dieta/análisis , Grasas de la Dieta/análisis , Proteínas en la Dieta/análisis , Ácidos Grasos/análisis , Vaciamiento Gástrico , Mucosa Gástrica/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Lactante , Fenómenos Fisiológicos Nutricionales del Lactante , Recien Nacido Prematuro , Lactalbúmina/sangre , Lactoferrina/sangre , Lipólisis , Proteínas de la Leche/química , Proteolisis , Albúmina Sérica/metabolismo , Esterol Esterasa/antagonistas & inhibidores , Esterol Esterasa/metabolismo
11.
Cancer Res ; 37(12): 4489-92, 1977 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-200351

RESUMEN

Antiserum to purified human alpha-lactalbumin was produced in rabbits and used to develop a radioimmunoassay capable of detecting 0.1 ng of alpha-lactalbumin per ml of sample. Human breast diseases were analyzed for alpha-lactalbumin levels. A high percentage of breast carcinomas contained varying levels of alpha-lactalbumin. Lymph node metastases from primary carcinomas that synthesized alpha-lactalbumin also contained it. Analysis of serum from breast cancer patients indicated that approximately 25 percent had measurable levels of alpha-lactalbumin before surgery, but no alpha-lactalbumin was found in postsurgery sera. alpha-Lactalbumin was not detected in the urine of early lactational women, although it was present in the sera. Human cell culture lines derived from pleural effusions of mammary carcinomas contained little, if any, alpha-lactalbumin. Other human cell lines derived from mammary carcinomas and grown as solid tumors in athymic mice did not contain measurable levels of alpha-lactalbumin.


Asunto(s)
Neoplasias de la Mama/análisis , Lactalbúmina/análisis , Neoplasias de la Mama/sangre , Carcinoma Intraductal no Infiltrante/análisis , Línea Celular , Femenino , Humanos , Lactalbúmina/sangre , Masculino , Metástasis de la Neoplasia/análisis , Neoplasias Experimentales/análisis , Radioinmunoensayo
12.
Food Funct ; 7(7): 2996-3005, 2016 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-27273451

RESUMEN

Alpha-lactalbumin (ALA) is one of the major allergens in cow's milk. However, research on its conformational epitopes has been relatively limited. In our study, specific antibodies against cow's milk ALA were purified from eight children by two-step affinity chromatography. Subsequently, mimotopes against IgG and IgE were biopanned from Ph.D.-12 and Ph.D.-C7C, respectively. Based on the mimotopes, linear epitopes were defined with the UniProt alignment tool. Conformational epitopes were computed using the Pepitope Server. Six IgE and seven IgG linear epitopes were identified. Meanwhile, five IgE and three IgG conformational epitopes were revealed with PyMOL. The results showed that common residues were identified in both IgE and IgG epitopes and some residues of the conformational epitopes were composed of linear epitopes on bovine α-lactalbumin. The results indicated that the data could be used for developing hypoallergenic dairy products on the basis of epitopes and providing a diagnostic tool for the assessment of patients who are allergic to cow's milk.


Asunto(s)
Epítopos/inmunología , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Hipersensibilidad a la Leche/inmunología , Alérgenos/inmunología , Animales , Niño , Preescolar , Cromatografía de Afinidad , Mapeo Epitopo , Femenino , Humanos , Inmunoglobulina E/inmunología , Inmunoglobulina G/inmunología , Lactante , Lactalbúmina/sangre , Lactalbúmina/inmunología , Masculino , Leche/química , Leche/inmunología , Conformación Proteica
13.
J Clin Endocrinol Metab ; 45(6): 1238-50, 1977 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22554

RESUMEN

A sensitive and specific radioimmunoassay for human alpha-lactalbumin, a milk protein, has been developed in order to examine the effect of prolactin on the human breast in normal and diseased states. Samples of milk from nursing mothers and from men and women with galactorrhea were found to contain milligram concentrations of this protein. In serum, 8 of 25 normal men and 18 of 44 normal women had detectable concentrations of alpha-lactalbumin. Significantly higher levels of alpha-lactalbumin were found in 17 of 19 women during pregnancy who were not actively lactating. All nursing mothers were found to have distinctly elevated serum alpha-lactalbumin concentrations. In a group of 17 female patients with phenothiazine induced prolactin elevations (mean 29.4 ng/ml), the mean serum alpha-lactalbumin of 17.3 ng/ml was significantly higher than in normal female volunteers. Patients with gynecomastia were not noted to have elevated alpha-lactalbumin. In vitro, homogenates of normal breast and carcinoma tissue from the same individuals revealed that in 9 of 17 patients alpha-lactalbumin was present in higher concentrations in normal than in cancerous tissue. Overall, alpha-lactalbumin was found in 48.5% of homogenates and 41% of organ cultures of normal breast tissue from cancer patients. In contrast, it was present in only 19% of homogenates and 21% of cultures of carcinoma tissue, indicating that the cancer tissue may lose its ability to produce alpha-lactalbumin. Differences in biologic behavior were found in some tumors. In 2 cases homogenates of breast cancer tissue had much higher concentrations of alpha-lactalbumin than the normal tissue, and in 3 of 33 tumors studied in organ culture prolactin increased alpha-lactalbumin output.


Asunto(s)
Neoplasias de la Mama/análisis , Mama/análisis , Lactalbúmina/análisis , Adolescente , Adulto , Anciano , Animales , Antipsicóticos/uso terapéutico , Línea Celular , Niño , Preescolar , Femenino , Ginecomastia/sangre , Haplorrinos , Humanos , Lactalbúmina/sangre , Masculino , Persona de Mediana Edad , Leche Humana/análisis , Técnicas de Cultivo de Órganos , Papio , Fenotiazinas , Embarazo , Radioinmunoensayo
14.
J Endocrinol ; 104(1): 77-85, 1985 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3968507

RESUMEN

Ten British Saanen goats were treated daily with 5 mg bromocriptine intramuscularly from week 8 of pregnancy until week 20 (day 140). By comparison with untreated control goats (n = 8), concentrations of prolactin in plasma were suppressed throughout the treatment period and remained significantly lower until 3 days prepartum, parturition occurring on day 153 +/- 0.7 (mean +/- S.E.M., n = 10). Growth hormone concentrations were low, but the incidence of levels exceeding 1 microgram/l was increased in bromocriptine-treated goats. Plasma concentrations of placental lactogen, progesterone and oestrone sulphate were unaffected. The accumulation of pre-colostrum in the udder (lactogenesis stage I) was not affected by bromocriptine treatment in goats carrying twin fetuses, but in goats with single kids it was delayed by about 4-6 weeks to week 17 of pregnancy. Secretion could not be expressed from the udder and the concentration of alpha-lactalbumin in plasma remained low. Udder volume was significantly reduced in week 15-16 but not week 20-21 of pregnancy by bromocriptine treatment. Milk yields after 50 or 203 days of lactation were not significantly different from those in control goats. Placental lactogen concentrations in late pregnancy and udder volume in week 20-21 were the only variables measured which correlated with milk yield post partum. It is concluded that in vivo placental lactogen is an effective mammotrophic hormone, although less potent than prolactin as evidenced by the delay in lactogenesis stage I in bromocriptine-treated goats bearing single kids.


Asunto(s)
Bromocriptina/farmacología , Hormona del Crecimiento/sangre , Lactancia/efectos de los fármacos , Glándulas Mamarias Animales/crecimiento & desarrollo , Prolactina/sangre , Animales , Estrona/análogos & derivados , Estrona/sangre , Femenino , Cabras , Lactalbúmina/sangre , Lactosa/sangre , Glándulas Mamarias Animales/efectos de los fármacos , Lactógeno Placentario/sangre , Periodo Posparto , Embarazo , Progesterona/sangre , Factores de Tiempo
15.
Clin Chim Acta ; 78(1): 129-33, 1977 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-560263

RESUMEN

A radioimmunoassay has been developed for the measurement of human lactalbumin, using the protein isolated in pure form from breast milk. Under disequilibrium conditions with second antibody separation the system will detect 20 pg of lactalbumin. Lactalbumin is detectable in the serum of approximately a third of normal male subjects; among women theproportion having measurable serum levels is age-related. Very much higher levels are present in the serum of lactating women.


Asunto(s)
Lactalbúmina/sangre , Adulto , Electroforesis Discontinua , Femenino , Humanos , Lactancia , Masculino , Métodos , Persona de Mediana Edad , Leche Humana/análisis , Embarazo , Radioinmunoensayo
16.
Clin Chim Acta ; 84(1-2): 207-11, 1978 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-565265

RESUMEN

Using a radioimmunoassay for the milk protein lactalbumin in human serum, we have found that falsely high results can be caused by cross-reacting human antibodies to bovine lactalbumin. A reliable method of circumventing this problem is described. When such interference had been eliminated, circulating lactalbumin was not detected in normal men or post-menopausal women, but could still be found in a proportion of non-pregnant, non-lactating pre-menopausal women.


Asunto(s)
Anticuerpos , Lactalbúmina/sangre , Adolescente , Adulto , Anciano , Animales , Bovinos/inmunología , Reacciones Cruzadas , Reacciones Falso Positivas , Femenino , Humanos , Lactalbúmina/inmunología , Masculino , Persona de Mediana Edad , Radioinmunoensayo/métodos
17.
Clin Chim Acta ; 163(3): 257-65, 1987 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-3581472

RESUMEN

A sandwich non-competitive enzyme immunoassay for the measurement of human alpha-lactalbumin in serum, milk, and tumour tissue cytosol was developed using affinity-purified polyclonal antibody adsorbed to solid phase. The detection limits of this procedure in tubes (macromethod) and in wells of microtitre plates (micromethod) are 50 pg and 25 pg/sample, respectively, which means 2.5 micrograms/l of serum at appropriate dilution. The micromethod enables a reduction of the volumes used in the reaction with equal sensitivity, accuracy and reproducibility. A comparison of alpha-lactalbumin concentrations in serum of healthy, pregnant, and lactating women determined by our method with those measured formerly by radioimmunoassays proved the specificity of our procedure.


Asunto(s)
Neoplasias de la Mama/análisis , Lactalbúmina/análisis , Leche Humana/análisis , Especificidad de Anticuerpos , Citosol/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Lactalbúmina/sangre , Lactancia , Masculino , Embarazo
18.
Clin Chim Acta ; 87(1): 149-57, 1978 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-566644

RESUMEN

Two radioimmunoassays for human lactalbumin have been established using a rabbit antiserum. One assay uses a second antibody to separate bound from free label; the other uses polyethylene glycol to precipitate gamma globulin non-specifically. We have confirmed that about half the normal human population have a substance in their blood which inhibits the binding of lactalbumin to the rabbit antibody. Comparison of the two assays has demonstrated that this material is not lactalbumin but a naturally occurring antibody. We have shown that it is in the IgG fraction of human plasma and is probably a cross-reacting antibody to bovine lactalbumin. None out of fifteen males and fourteen out of fifty eight non-pregnant, non-lactating females had low levels of lactalbumin in the their blood (0.6--2.0 ng/ml). Our assay could not detect a statistically significant difference between normal women and those with either benign breast disease or metastatic mammary carcinoma.


Asunto(s)
Anticuerpos , Lactalbúmina/sangre , Animales , Anticuerpos/análisis , Bovinos/inmunología , Cromatografía DEAE-Celulosa , Cromatografía en Gel , Reacciones Cruzadas , Femenino , Humanos , Inmunoglobulina G/análisis , Lactalbúmina/inmunología , Masculino , Polietilenglicoles , Embarazo , Conejos/inmunología , Radioinmunoensayo/métodos
19.
Res Vet Sci ; 53(2): 219-22, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1439212

RESUMEN

Seven Friesian calves were fed colostrum for four days beginning within 24 hours of birth, and milk thereafter. The concentration of alpha-lactalbumin in serum was measured by specific radioimmunoassay and compared to IgG assayed by electroimmunodiffusion. Serum concentrations of alpha-lactalbumin peaked at 387 +/- 85 ng ml-1 within eight hours of initial intake of colostrum, declining to 12 +/- 3 ng ml-1 by day 6. IgG rose steadily to 17 mg ml-1 by 48 hours of birth and remained relatively constant thereafter. The temporal pattern of alpha-lactalbumin in serum following colostrum intake confirms previous studies suggesting reduced absorption of colostral proteins between 24 and 36 hours. The presence of variable amounts of alpha-lactalbumin in serum even after 17 days, however, indicates limited transfer of milk-derived proteins across the gut at this time. The data further show that cessation of maximal gut transfer does not relate to molecular weight of transferred protein.


Asunto(s)
Animales Recién Nacidos/sangre , Bovinos/sangre , Calostro/fisiología , Lactalbúmina/sangre , Animales , Inmunodifusión/métodos , Inmunodifusión/veterinaria , Inmunoglobulina G/sangre , Intestinos/fisiología , Radioinmunoensayo/veterinaria
20.
Eksp Onkol ; 7(5): 56-60, 1985.
Artículo en Ruso | MEDLINE | ID: mdl-4065022

RESUMEN

An enzyme-linked immunosorbent assay (ELISA) has been used for quantitative determination of lactoferrin (Lf) and alpha-lactalbumin (alpha-La) in human blood serum. The mean concentration of Lf in normal serum was 265 +/- 21 ng/ml and that of alpha-La did not exceed 5 ng/ml. The increased Lf level (above 450 ng/ml) was found in 16 of 30 (53%) patients with gastrointestinal cancer, in 11 of 25 (44%)--with lung cancer, in 13 of 42 (31%)--with breast cancer and more rarely--in other cancer patients. The increased alpha-La level (above 5.0 mg/ml) was found in 5 of 42 patients with breast cancer and very rarely--in other cancer patients. A conclusion is drawn that serological measurements of Lf and alpha-La were of no diagnostic value for breast cancer.


Asunto(s)
Lactalbúmina/sangre , Lactoferrina/sangre , Lactoglobulinas/sangre , Neoplasias/sangre , Donantes de Sangre , Neoplasias de la Mama/sangre , Neoplasias de la Mama/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Neoplasias/diagnóstico
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