Whey protein dynamics in goat mammary secretions during colostrum and early lactation periods.

The protein composition in goat milk undergoes changes throughout the different lactation periods, displaying distinct characteristics that are influenced by the dynamic nature of protein composition and concentration during the transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Saanen goats during the colostral phase and the first month of lactation, 110 milk samples from 11 healthy mammary halves of seven Saanen goats were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The biuret method determined total protein concentration, and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis. Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing throughout the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred 5 or 7 d postpartum.

Secretory carcinoma of the canine mammary gland with nodal and bone metastases: Case report.

Background: Secretory carcinoma is a rare histological type of breast neoplasm in humans and dogs that is characterized by the presence of intracellular and extracellular eosinophilic secretions. Case Description: In this case report, we describe the cytological, histological, and immunohistochemical characteristics of secretory mammary carcinoma in a 10-year-old mixed-breed female dog with nodal and bone metastases. The bitch had a history of claudication and a mass in the left humeral scapular region, which revealed osteolysis of the proximal humerus on radiography. Fine-needle aspiration cytology revealed numerous neoplastic cells arranged mostly in cohesive groups but sometimes isolated, that contained cytoplasmic vacuoles and had a moderate-to-high nucleus: cytoplasm ratio with frequent karyomegaly and evident nucleoli. Histologically, the neoplasm was organized in solid, tubular structures with luminal spaces filled with eosinophilic secretions and was composed of cells with clear cytoplasm and prominent vacuoles that pushed the nuclei to the periphery, resembling signet ring cells. The extracellular and intracytoplasmic material of the epithelial cells was positive for periodic acid-Schiff staining and immunoreactive for alpha-lactalbumin. Two chemotherapy sessions were performed, but 1 month after surgery, the clinical condition worsened, and euthanasia was elected, accounting for 133 days of survival after surgical removal of the tumor. Conclusion: The bitch presented with secretory mammary carcinoma with nodal and bone metastases, and histological and immunohistochemical characteristics were important for diagnosis. The morphological and immunohistochemical characteristics of this carcinoma were similar to those observed in humans. Mammary gland secretory carcinoma with bone metastasis must be included as a differential diagnosis among canine mammary gland carcinomas showing cellular morphological characteristics of intracytoplasmic vacuolization and eosinophilic secretion.

Bisphenol A and benzophenone-3 exposure alters milk protein expression and its transcriptional regulation during functional differentiation of the mammary gland in vitro.

The plastic monomer and plasticizer bisphenol A (BPA), and the UV-filter benzophenone-3 (BP3) have been shown to have estrogenic activities that could alter mammary gland development. Our aim was to analyze whether BPA or BP3 direct exposure affects the functional differentiation of the mammary gland using an in vitro model. Mammary organoids were obtained and isolated from 8 week-old virgin female C57BL/6 mice and were differentiated on Matrigel with medium containing lactogenic hormones and exposed to: a) vehicle (0.01% ethanol); b) 1 × 10-9 M or 1 × 10-6 M BPA; or c) 1 × 10-12 M, 1 × 10-9 M or 1 × 10-6 M BP3 for 72 h. The mRNA and protein expression of estrogen receptor alpha (ESR1) and progesterone receptor (PR) were assessed. In addition, mRNA levels of PR-B isoform, glucocorticoid receptor (GR), prolactin receptor (PRLR) and Stat5a, and protein expression of pStat5a/b were evaluated at 72 h. The mRNA and protein expression of milk proteins and their DNA methylation status were also analyzed. Although mRNA level of PRLR and GR was similar between treatments, mRNA expression of ESR1, total PR, PR-B and Stat5a was increased in organoids exposed to 1 × 10-9 M BPA and 1 × 10-12 M BP3. Total PR expression was also increased with 1 × 10-6 M BPA. Nuclear ESR1 and PR expression was observed in all treated organoids; whereas nuclear pStat5a/b alveolar cells was observed only in organoids exposed to 1 × 10-9 M BPA and 1 × 10-12 M BP3. The beta-casein mRNA level was increased in both BPA concentrations and 1 × 10-12 M BP3, which was associated with hypomethylation of its promoter. The beta-casein protein expression was only increased with 1 × 10-9 M BPA or 1 × 10-12 M BP3. In contrast, BPA exposure decreased alpha-lactalbumin mRNA expression and increased DNA methylation level in different methylation-sensitive sites of the gene. Also, 1 × 10-9 M BPA decreased alpha-lactalbumin protein expression. Our results demonstrate that BPA or BP3 exposure alters milk protein synthesis and its transcriptional regulation during mammary gland differentiation in vitro.

The dynamics of individual whey protein concentrations in cows' mammary secretions during the colostral and early lactation periods.

The bovine whey consists of more than 200 different types of proteins, of which ß-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulins and lactoferrin predominate. However, their concentrations are not stable due to the existence of protein dynamics during a transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Jersey cows during a colostral phase and first month of lactation and an influence of the number of lactations, 268 milk samples from 135 Jersey cows were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The concentration of total proteins was determined by the biuret method and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis (12% SDS-PAGE). Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing over the course of the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred between 24 and 72 h postpartum. There was an influence of the number of lactations on the dynamics of whey proteins, indicating that multiparous cows had better immunological and nutritional quality when compared to primiparous cows.

Efeito protetor das frações proteicas do soro de leite em camundongos Balb/C infectados por Escherichia coli O157: H7 / Protective effect of whey proteic fractions on Balb/C mice infected by Escherichia coli O157: H7

Avaliou-se o efeito protetor das frações proteicas do soro do leite sobre as vilosidades intestinais de camundongos Balb/C, fêmeas, infectadas por Escherichia coli O157:H7. Foram utilizados 48 animais, distribuídos aleatoriamente em oito grupos de seis fêmeas cada um. Os animais dos grupos 1 e 2 (controles) receberam dieta AIN93G padrão; os dos grupos 3 e 4, AIN93G + alfalactalbumina; os dos grupos 5 e 6, AIN93G + betalactoglobulina e os dos grupos 7 e 8, AIN93G + concentrado proteico total e água ad libitum por sete dias. No dia zero, os animais dos grupos 2, 4, 6 e 8 foram inoculados, por meio de cânula de gavagem, com 0,5mL de E. coli O157:H7, na concentração de 7 x 10(10)UFC/mL. Os animais foram acompanhados clinicamente e sacrificados, no oitavo dia experimental. Verificou-se, por meio de exames histológicos e da morfometria, que as frações betalactoglobulina e alfalactalbumina exerceram efeito protetor sobre as vilosidades intestinais do jejuno distal e do íleo (P<0,05), respectivamente. O concentrado proteico total não demonstrou efeito protetor sobre as vilosidades intestinais.(AU)

The protective effect of protein fractions of whey on intestinal villi of Balb/C female mice infected with Escherichia coli O157: H7 was evaluated. A total of 48 animals were randomly distributed into eight groups of six females each. Animals in groups 1 and 2 (controls) received AIN93G standard diet; the groups 3 and 4, AIN93G + alpha-lactalbumin; while groups 5 and 6, AIN93G + beta-lactoglobulin; and groups 7 and 8, AIN93G + total protein concentrate and water ad libitum for seven days. On day zero, animals of groups 2, 4, 6, and 8 were inoculated by gavage tube with 0.5mL of E. coli O157: H7 at a concentration of 7 x 10(10)CFU/mL. The animals were clinically followed and sacrificed on the eighth day. It was verified by histological examination and morphometry that the beta-lactoglobulin and alpha-lactalbumin exerted a protective effect on the villi of the distal jejunum and ileum (P<0.05), respectively. The total protein concentrate showed no protective effect on the villi.(AU)

Efeito protetor das frações proteicas do soro de leite em camundongos Balb/C infectados por Escherichia coli O157: H7 / Protective effect of whey proteic fractions on Balb/C mice infected by Escherichia coli O157: H7

Avaliou-se o efeito protetor das frações proteicas do soro do leite sobre as vilosidades intestinais de camundongos Balb/C, fêmeas, infectadas por Escherichia coli O157:H7. Foram utilizados 48 animais, distribuídos aleatoriamente em oito grupos de seis fêmeas cada um. Os animais dos grupos 1 e 2 (controles) receberam dieta AIN93G padrão; os dos grupos 3 e 4, AIN93G + alfalactalbumina; os dos grupos 5 e 6, AIN93G + betalactoglobulina e os dos grupos 7 e 8, AIN93G + concentrado proteico total e água ad libitum por sete dias. No dia zero, os animais dos grupos 2, 4, 6 e 8 foram inoculados, por meio de cânula de gavagem, com 0,5mL de E. coli O157:H7, na concentração de 7 x 10(10)UFC/mL. Os animais foram acompanhados clinicamente e sacrificados, no oitavo dia experimental. Verificou-se, por meio de exames histológicos e da morfometria, que as frações betalactoglobulina e alfalactalbumina exerceram efeito protetor sobre as vilosidades intestinais do jejuno distal e do íleo (P<0,05), respectivamente. O concentrado proteico total não demonstrou efeito protetor sobre as vilosidades intestinais.

The protective effect of protein fractions of whey on intestinal villi of Balb/C female mice infected with Escherichia coli O157: H7 was evaluated. A total of 48 animals were randomly distributed into eight groups of six females each. Animals in groups 1 and 2 (controls) received AIN93G standard diet; the groups 3 and 4, AIN93G + alpha-lactalbumin; while groups 5 and 6, AIN93G + beta-lactoglobulin; and groups 7 and 8, AIN93G + total protein concentrate and water ad libitum for seven days. On day zero, animals of groups 2, 4, 6, and 8 were inoculated by gavage tube with 0.5mL of E. coli O157: H7 at a concentration of 7 x 10(10)CFU/mL. The animals were clinically followed and sacrificed on the eighth day. It was verified by histological examination and morphometry that the beta-lactoglobulin and alpha-lactalbumin exerted a protective effect on the villi of the distal jejunum and ileum (P<0.05), respectively. The total protein concentrate showed no protective effect on the villi.

ESTABILIZACIÓN DE HOLO-α-LACTOALBÚMINA EN PRESENCIA DE POLIOLES / HOLO-α-LACTALBUMLN STABILIZATION IN THE PRESENCE OF POLYOLS / ESTABILIDADE TÉRMICA DA HOLO-α-LACTOALBUMFNA EM PRESENÇA DE POLIÓIS

En este trabajo se presenta un estudio sistemático sobre el efecto de las soluciones acuosas de eritritol, xilitol, sorbitol e inositol con diferentes concentraciones, sobre la estabilidad térmica de la holo-α-lactoalbúmina bovina con pH 6,5 usando espectroscopia UV-VIS. Los resultados obtenidos muestran que los polioles usados estabilizan la holo-α-lactoalbúmina en un grado significativamente menor al reportado para otras proteínas. Se sugiere que este menor efecto de estabilización ocurre debido a que esta proteína presenta un estado desnaturalizado parcialmente desdoblado.

In this work we present a systematic study of the effect of aqueous solutions of erythritol, xylitol, sorbitol and inositol on thermal stability of bovine holo-α-lactalbumin at pH 6,5 using UV-VIS spectroscopy. The results show that the polyols used stabilize the holo-α-lactoalbumin in a significant lesser extent than the reported for others proteins. It is suggested that the lower stabilization achieved for this protein is the result of a partially unfolded denaturated state that this protein presents.

Neste trabalho é apresentado um estudo sistemático acerca do efeito de soluções aquosas de eritritol, xilitol, sorbitol e inositol a diferentes concentrações sobre a estabilidade térmica da holo-α-lactoalbumina bovina a pH 6,5 usando espectroscopia UV-VIS. Os resultados obtidos mostram que os polióis usados estabilizam a holo-α-lactoalbumina num grado significativamente menor ao reportado para outras proteínas. Se sugere que este menor efeito de estabilização ocorre devido a que esta proteína apresenta um estado desnaturalizado parcialmente desdobrado.