High Concentrations In Milk Research Articles

Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier

Osteopontin (OPN) is a bioactive integrin-binding protein found in high concentrations in milk, where it is present both as a full-length protein and as several N-terminally derived fragments. OPN resists gastric digestion, and via interaction with receptors in the gut or by crossing the intestinal barrier into circulation, ingested milk OPN may influence physiological processes. The aim of this study was to investigate OPN interaction with intestinal cells and its transport across models of the intestinal barrier. Immunodetection of OPN incubated with Caco-2 cells at 4 °C and 37 °C showed that OPN binds to the intestinal cells, but it is not internalised. Transepithelial transport was studied using mono- and co-cultures of Caco-2 cells and mucus-producing HT29-MTX cells in transwell membranes. OPN was shown to cross the barrier models in a time-, temperature-, and energy-dependent process inhibited by wortmannin, indicating that the transport takes place via the transcytosis pathway. Analyses of the naturally occurring milk mixture of full-length and N-terminal fragments showed that the N-terminal fragments of OPN bound intestinal cells most effectively and that the fragments were transported across the intestinal membrane models. This suggests that proteolytic processing of OPN increases its biological activity after ingestion.

IN-VITRO INVESTIGATION OF DONKEY MILK EFFICACY AGAINST STANDARD STAPHYLOCOCCUS AUREUS STRAINS

has been used for therapeutic purposes since ancient times. Different studies report its antimicrobial activity against an important human pathogen such as S. aureus. Therefore, in our study, we aimed to examine the antimicrobial efficacy of donkey milk against standard MRSA and MSSA strains in-vitro environment. In our study, in-vitro antimicrobial efficacy of donkey milk obtained from 53 different donkeys against S. aureus ATCC 43300 (MRSA) and S. aureus ATCC 29213 (MSSA) was investigated by broth microdilution method. Donkey milk mixed with TSB medium at different serial dilution rates was studied in 96 microwell plates. When the effectiveness of different concentrations of donkey milk added to TSB medium in vitro against ATCC MRSA and MSSA strains was examined, no suppression was observed, and growth was found to be higher than the control results after 24 hours of incubation at high milk concentrations. In conclusion, according to the results of our study, no antimicrobial effect of donkey milk was observed in-vitro against standard MRSA and MSSA strains. This situation may be caused by the fact that S. aureus strains may have different virulence abilities, as well as the differences in protein structure in milk between species.

PK/PD integration and pharmacodynamic cutoff of cefquinome against cow mastitis due to Escherichia coli.

Cefquinome is the fourth generation of cephalosporin approved solely in animal usage. In order to slow down the resistance development of E.coli to cefquinome, and to protect and maintain the effectiveness of cefquinome, an ex vivo PK/PD modeling of cefquinome against E.coli in cows after intramammary infusion administration was conducted. The epidemiologic cutoff (ECOFF) and pharmacodynamic cutoff (COPD) of cefquinome against E.coli in lactation cows after intramammary infusion administration were recommended. The MICs of cefquinome against 1073clinical E.coli isolates ranged from 0.015 to >64μg/ml, and the ECOFF was defined as 0.125μg/ml. The pharmacokinetic results showed that cefquinome maintained high concentration in milk for a long period with the T1/2β of 10.60h after intramammary infusion in dairy cows. The drug concentration in skimmed milk was still as high as 0.15mg/ml after 48h. Cefquinome displayed bacterial killing effect at 2× MIC with the initial inoculum of 106 cfu/ml in vitro; however, the same effect was attained with a concentration as high as 32× MIC with the initial inoculum of 108 cfu/ml both in artificial medium and in skimmed milk. The initial inoculum is an important factor on time-killing curve accounting for weakened killing pattern of cefquinome. The AUC0-24h /MIC index correlated well with ex vivo efficacy. The AUC0-24h /MIC values for bactericidal effect were 50, 016, and 67,644, respectively, for initial inoculum of 106 and 108 cfu/ml, indicating the bacterial loading or the severity of infection would infect the PK/PD modeling results. The ex vivo PK/PD-based population dose prediction indicated a target attainment rate (TAR) at the existing daily dose (75mg/udder) of 84.77% against E.coli. Thus, it was recommended as rational dosage. The COPD of cefquinome against E.coli was determined as 8μg/ml at the dose of 75mg/udder. The derived ECOFF, COPD, together with ex vivo PK/PD-based population dose prediction served as important steps in the establishment of optimum dose regimen and provided a useful interpretative criterion to categorize the antimicrobial susceptibility testing results of cefquinome.

Comparison of Bovine Mammary Involution and Intramammary Infections Following Intramammary Treatment with Casein Hydrolysate and Other Conventional Treatments at Dry-Off.

Alternatives to routine antibiotic treatment of dairy cattle during the dry period before their next calving are of interest. This was a preliminary study of whether intramammary infusion of casein hydrolysate, administered alone or combined with standard dry treatment, accelerated the rate of mammary involution early in the dry period. Four treatments were studied in a split udder design. One udder half was assigned a treatment, and the contralateral half was administered dry cow treatment + internal teat sealant as a control. Treatments were casein hydrolysate, casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and casein hydrolysate + dry cow treatment + teat sealant. Cows (n = 16) were blocked by a number of intramammary infections per udder half (0 or 1+) and randomized to treatments. Milk production was not different between control or treated udder halves post-calving. A generalized linear mixed model tested for differences between the treatment groups in the concentration of mammary involution indicators in milk: somatic cell count, bovine lactoferrin and bovine serum albumin. At 7 days, dry udder halves treated with casein hydrolysate had higher milk concentrations of lactoferrin than those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and control. At 10 days dry, bovine serum albumin was higher in udder halves treated with casein hydrolysate than in those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + dry cow treatment + teat sealant and control. Post-calving, casein hydrolysate-treated udder halves produced 51% of total milk, unchanged from before dry-off. There were seven total intramammary infections entering the dry period, all caused by coagulase-negative staphylococci. Cure rates (3/7, 43%) were not different among all treatments and control, partly because of the small sample size. Intramammary infusion of casein hydrolysate at the end of lactation may be an alternative or possible adjunct to antibiotic dry cow therapy.

Milk and Plasma Lutein and Zeaxanthin Concentrations in Chinese Breast-Feeding Mother–Infant Dyads With Healthy Maternal Fruit and Vegetable Intake*

Objectives: While others have reported that milk from coastal Chinese women contains high levels of lutein and zeaxanthin, no research has determined the corresponding infant plasma response. Whether infant plasma levels increase commensurately provides important guidance for supplementation of these increasingly intriguing carotenoids in breast-feeding mothers and formula-fed infants.Methods: Fifty-six mother–infant pairs with a maternal diet rich in eggs, green leafy vegetables, and fruit were enrolled between 6 and 16 weeks of lactation. Milk samples and blood samples from both the mother and infant were collected at entry. Maternal 3-day dietary records and a second milk sample were collected 1 to 3 weeks later.Results: Mean milk lutein concentrations in samples 1 and 2 were 6.5 and 7.7 μg/dL (range 1–22.5 μg/dL), and for zeaxanthin, 1.6 and 1.7 μg/dL (range 1–5.9 μg/dL). Lutein concentrations in infant plasma (18.2 μg/dL) were similar to those in maternal plasma (21.6 μg/dL); zeaxanthin was lower than lutein in both maternal (3.1 μg/dL) and infant (2.9 μg/dL) plasma. Infant and maternal mean plasma lutein and zeaxanthin concentrations were higher than those in both milk samples 1 and 2 (lutein, 6.9 and 8.2 μg/dL; zeaxanthin, 1.9 and 2.0 μg/dL). Infant plasma lutein and zeaxanthin concentrations positively correlated with those in milk sample 1 (lutein, r2 = 0.15, p = 0.004; zeaxanthin, r2 = 0.21, p < 0.001).Conclusions: Together, these results reveal that high milk concentrations of lutein and zeaxanthin driven by healthy maternal intakes of xanthophyll rich foods are associated with high infant plasma concentrations. These findings will be useful for determining appropriate lutein fortification strategies.Clinical Study.gov registration number: NCT01669655.

Bovine lactoferrin and lactoferricin exert antitumor activities on human colorectal cancer cells (HT-29) by activating various signaling pathways.

Lactoferrin (Lf) is an iron-binding glycoprotein that is present at high concentrations in milk. Bovine lactoferricin (LfcinB) is a peptide fragment generated by pepsin proteolysis of bovine lactoferrin (bLf). LfcinB consists of amino acid residues 17-41 proximal to the N-terminus of bLf and a disulfide bond between residues 19 and 36, forming a loop. Both bLf and LfcinB have been demonstrated to have antitumor activities. Colorectal cancer is the second most common cause of cancer death in developed countries. We hypothesized that bLf and LfcinB exert antitumor activities on colon cancer cells (HT-29) by triggering various signaling pathways. bLf and LfcinB significantly induced apoptosis in HT-29 cells but not in normal human intestinal epithelial cells, as revealed by the ApoTox-Glo Triplex Assay. The LIVE/DEAD cell viability assay showed that both bLf and LfcinB reduced the viability of HT-29 cells. Transcriptome analysis indicated that bLf, cyclic LfcinB, and linear LfcinB exerted antitumor activities by differentially activating diverse signaling pathways, including p53, apoptosis, and angiopoietin signaling. Immunoblotting results confirmed that both bLf and LfcinBs increased expression of caspase-8, p53, and p21, critical proteins in tumor suppression. These results provide valuable information regarding bLf and LfcinB for potential clinical applications in colon cancer therapy.

ABC- and SLC-Transporters in Murine and Bovine Mammary Epithelium--Effects of Prochloraz.

Some chemicals are ligands to efflux transporters which may result in high concentrations in milk. Limited knowledge is available on the influence of maternal exposure to chemicals on the expression and function of transporters in the lactating mammary gland. We determined gene expression of ABC and SLC transporters in murine mammary tissue of different gestation and lactation stages, in murine mammary cells (HC11) featuring resting and secreting phenotypes and in bovine mammary tissue and cells (BME-UV). Effects on transporter expression and function of the imidazole fungicide prochloraz, previously reported to influence BCRP in mammary cells, was investigated on transporter expression and function in the two cell lines. Transporters studied were BCRP, MDR1, MRP1, OATP1A5/OATP1A2, OCTN1 and OCT1. Gene expressions of BCRP and OCT1 in murine mammary glands were increased during gestation and lactation, whereas MDR1, MRP1, OATP1A5 and OCTN1 were decreased, compared to expressions in virgins. All transporters measured in mammary glands of mice were detected in bovine mammary tissue and in HC11 cells, while only MDR1 and MRP1 were detected in BME-UV cells. Prochloraz treatment induced MDR1 gene and protein expression in both differentiated HC11 and BME-UV cells and increased protein function in HC11 cells, resulting in decreased accumulation of the MDR1 substrate digoxin. In conclusion, our results demonstrate that murine (HC11) and bovine (BME-UV) mammary epithelial cells can be applied to characterize expression and function of transporters as well as effects of contaminants on the mammary transporters. An altered expression, induced by a drug or toxic chemical, on any of the transporters expressed in the mammary epithelial cells during lactation may modulate the well-balanced composition of nutrients and/or secretion of contaminants in milk with potential adverse effects on breast-fed infants and dairy consumers.

Transforming growth factor-β2 is sequestered in preterm human milk by chondroitin sulfate proteoglycans.

Human milk contains biologically important amounts of transforming growth factor-β2 isoform (TGF-β2), which is presumed to protect against inflammatory gut mucosal injury in the neonate. In preclinical models, enterally administered TGF-β2 can protect against experimental necrotizing enterocolitis, an inflammatory bowel necrosis of premature infants. In this study, we investigated whether TGF-β bioactivity in human preterm milk could be enhanced for therapeutic purposes by adding recombinant TGF-β2 (rTGF-β2) to milk prior to feeding. Milk-borne TGF-β bioactivity was measured by established luciferase reporter assays. Molecular interactions of TGF-β2 were investigated by nondenaturing gel electrophoresis and immunoblots, computational molecular modeling, and affinity capillary electrophoresis. Addition of rTGF-β2 (20-40 nM) to human preterm milk samples failed to increase TGF-β bioactivity in milk. Milk-borne TGF-β2 was bound to chondroitin sulfate (CS) containing proteoglycan(s) such as biglycan, which are expressed in high concentrations in milk. Chondroitinase treatment of milk increased the bioactivity of both endogenous and rTGF-β2, and consequently, enhanced the ability of preterm milk to suppress LPS-induced NF-κB activation in macrophages. These findings provide a mechanism for the normally low bioavailability of milk-borne TGF-β2 and identify chondroitinase digestion of milk as a potential therapeutic strategy to enhance the anti-inflammatory effects of preterm milk.

Different chronological patterns of appearance of blood derived milk components during mastitis indicate different mechanisms of transfer from blood into milk.

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.

Lamb performance, milk production and composition from ewes supplemented with soybean oil partially replaced by fish oil blend

The objectives of these experiment were to evaluate the effects of small amounts of fish oil blend supply in partial replacement of soybean oil on dry matter intake (DMI), lactation performance and milk fatty acid composition of ewes and also on performance of their lambs. Fifty Santa Inês lactating ewes (63±6kg of initial BW; mean±SD) were penned individually and used in a randomized complete block design with 10 blocks and 5 treatments. The oils were added to a basal diet that contained 700g/kg DM of concentrate and 300g/kg DM of forage (fresh sugarcane bagasse). The treatments were as follows: (1) basal diet without added oil (CONT); (2) 40g/kg DM of soybean oil (0FO); (3) 2.5g/kg DM of fish oil blend+37.5g/kg DM of soybean oil (25FO); (4) 5g/kg DM of fish oil blend+35g/kg DM of soybean oil (50FO); and (5) 7.5g/kg DM of fish oil blend+32.5g/kg DM of soybean oil (75FO). All diets were isonitrogen (140±4g/kg DM of CP). Once a week, from the second to the eighth week of lactation (weaning time), ewes were separated from their lambs, stimulated by a 6-IU intravenous oxytocin injection, and milked to empty the udder. After 3h, milk production was obtained after the same procedure. DMI (kg/d; % of BW and g/kg BW0.75) was higher for ewes fed the control diets vs. fat-supplemented. However, no effect was observed on DMI when fish oil blend inclusion in the diets increased. Nevertheless, milk production increased linearly when fish oil blend replaced soybean oil. As a consequence, the preweaning average daily gain (ADG) of lambs increased linearly. Milk fat concentration was similar for all diets. Milk protein and total solids concentrations decreased linearly when fish oil blend addition increased. Lactose milk concentration was higher for ewes fed the fat-supplemented diets vs. the control. Stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid and CLA cis-9, trans-11 showed higher concentrations in milk of animals fed diets containing soybean oil and fish oil blend compared to the control diet. Vaccenic acid, CLA trans-10, cis-12, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased linearly with fish oil blend inclusion. Small amounts of fish oil supplementation does not exert an additional effect on the concentration of CLA C18:2 cis-9, trans-11 as compered to exclusive use of soybean oil. However, the addition of 7.5g/kg DM of fish oil blend mixed with 32.5g/kg DM of soybean oil is recommended, because it increased the concentration of EPA, DHA and C18:1 trans-11 in the milk, as well increasing the performance of the ewes and their lambs.

Análise de Resíduos de Diclofenaco Sódico Veterinário em Leite por Espectroscopia no Infravermelho Próximo

Introduction: Milk is one of most consumed food by human beings, especially children and elderly. In 2007, the Federal Police conducted an operation that showed an enormous fraud scheme in industrialized milk in Brazil. In addition, they found out that 1/3 of the milk consumed in Brazil did not pass by inspection. There are several ways to adulterate milk, such as with addition of water, caustic soda, sodium chloride and others. However, there is another issue, that is, milk contamination with veterinary drugs. These drugs may be present in high concentrations in milk, in case the cow was milked in the clearance period. Contaminated milk can cause damages to consumers’ health or injury to the production of derivates. Objective: To develop a complementary technique to detect the presence of residues of veterinary drugs in milk samples. Material and Methods: currently, given the technological development, there are many techniques based on multielement analysis for studying the chemical components of different samples. This paper uses the technique of Fourier Transform Near Infrared Spectroscopy and the Principal Components Analysis (PCA) to detect the evidence of residues of veterinary drugs in milk. To this end, we simulated adulteration in milk with percentages of 0.1%, 0.5% and 10% drugs in milk. Results: cryoscopy: 0.539 oH with 0.18% water; non-acid milk according to Alizarol test; pH 6.71; Fat: 3.25%; Protein: 3.01%; Lactose: 4.55%; Solids: 10.80%. Drug residues were observed via the first derivative of reflectance spectra and PCA analysis at levels below 1%. Conclusion: The result was positive indicating that the FT-NIR system can detected the residues of studied drugs within the simulated percentage. DESCRIPTORS Milk. Drug. Diclofenac. Spectroscopy, Near-Infrared.

Upregulation Of Hepcidin Expression By Lactoferrin Administration To Pre-Weanling Mice

BackgroundHepcidin is a peptide hormone produced in hepatocytes which regulates dietary iron absorption and systemic iron distribution. The hepatic expression of the hepcidin gene is regulated by signals which reflect body iron status and erythropoietic activity. The regulation of hepcidin by iron status includes a signal from the circulating transferrin via hepatocellular transferrin receptor (TfR2). Lactoferrin is a member of the transferrin family of iron-binding glycoproteins found in high concentrations in milk. Lactoferrin has a well described role in host defense; however, its in iron metabolism is less clear. Like transferrin, lactoferrin will deliver iron to hepatocytes but unlike transferrin, lactoferrin cannot deliver iron to erythroid cells. Lactoferrin does not interact with TfR1 or TfR2. We took advantage of these properties of lactoferrin to determine if delivering iron to the liver (but not erythron) in a form which is independent on transferrin and its receptors could regulate hepcidin. MethodsTo take advantage of the naturally-occuring low iron and low hepcidin states at this developmental stage, experiments were performed on pre-weanling mice. Mice at 12-14d (pre-weanling) were administered human lactoferrin equivalent to 2 mg/kg iron (n=10) or carrier (n=10) intraperitoneally (IP) and sacrificed 6 h later. Other mice were administered a comparable IP dose of transferrin (n=5) or carrier (n=4). Additional groups of mice were delivered Lf (n=8) or carrier (n=7) enterally (by orogastric tube), and the sacrificed 6h or 24h later. Liver hepcidin (Hamp1) mRNA was measured by real-time RT-PCR, normalized to beta actin expression, and analyzed by commercial software (Rest 2007, Qiagen). Liver iron distribution was determined histochemically in tissue sections by modified Perls' staining. ResultsParenteral administration of lactoferrin in pre-weanling mice was associated with a 32-fold increase in liver Hamp1 expression after 6 hours (P<0.001). This compares with an only 4.5 fold increase in Hamp1 expression 6h after a comparable dose of transferrin. Enteral lactoferrin likewise resulted in a ∼30-fold increase in Hamp1 expression (P<0.005) after 24 hours. Iron delivered to the liver from lactoferrin was distributed in sinusoidal lining cells as well as hepatocytes. ConclusionsExogenously administered iron-rplete lactoferrin increases liver Hamp1 expression in pre-weanling mice. These observations demonstrate that iron delivery to the liver in a form not dependent upon transferrin or its receptors upregulates hepcidin expression. These findings moreover raise the possibility that lactoferrin-mediated changes in hepcidin expression may contribute to reported benefits of supplemental lactoferrin on host defense. Disclosures:No relevant conflicts of interest to declare.

Pressure-Induced Denaturation of β-Lactoglobulin in Skim Milk: Effect of Milk Concentration

The effect of milk concentration (10-40% TS) on the kinetics of the pressure-induced denaturation of β-lactoglobulin (β-LG) was studied. The denaturation was found to be a second-order process at all milk concentrations and pressures. There was a change in pressure dependence of the rate constants for denaturation at about 300 MPa, and this effect became more pronounced as the milk concentration increased. At pressures ≥300 MPa, a small effect of milk concentration was observed, with small decreases in the rate of denaturation as the milk concentration was increased above 20% TS. This was attributed to the lower pH as the milk concentration was increased. In contrast, at 200 MPa, β-LG denaturation was markedly retarded as the milk solids concentration was increased. This was attributed to the increased lactose concentration at higher milk concentrations. This would promote β-LG dimerization at this pressure and this would stabilize the β-LG to denaturation.

Bovine lactoferrin and bovine lactoferricin are internalized by colon cancer cells and exhibit elevated apoptosis

Lactoferrin (Lf) is an iron‐binding glycoprotein and is present at high concentrations in milk from several species. Bovine lactoferricin (bLfcin) is a peptide fragment produced by acid‐pepsin hydrolysis of bovine lactoferrin (bLf). BLfcin consists of amino acid residues 17–42 proximal to the N‐terminal of bLf and a cysteine–cysteine disulfide bond between residues 19 and 36 creating a cyclic form. Both bLf and BLfcin have been shown to have anti‐tumor activities. Colorectal cancer is the 2nd most common cause of cancer deaths in developed countries. Therefore, we hypothesized that both bLf and bLfcin are internalized by colon cancer cells (HT‐29) and stimulate apoptosis of these cells. Confocal microscopy showed that bLfcin in linear and cyclic forms and bLf were internalized by HT‐29 cells. ApoTox‐Glo Triplex Assay (Promega) results show that bLfcin and bLf significantly stimulated apoptosis of colon cancer cells in a concentration‐dependent pattern and maximal effects were obtained at 12‐h of treatment. No significant differences were found between the two forms of bLfcin, but the effect on apoptosis triggered by bLfcin was stronger than that by bLf. In summary, both bLfcin and bLf are internalized by colon cancer cells and stimulate apoptosis of these cells, suggesting potential clinical applications for bLf and bLfcin in colon cancer.

In vitro Culture alters the Expression of Xenobiotic Transporters by Mammary Epithelial Cells

Some drugs and toxins are actively transported across the mammary epithelial barrier, resulting in high milk concentrations. To assess potential exposure through milk, in vitro models of the mammary epithelial barrier are needed. The goal of these studies was to compare the expression of xenobiotic transporters between native tissues, cultures of freshly isolated bovine mammary epithelial cells and a bovine mammary epithelial cell line (BME‐UV). Real time PCR was employed to evaluate the expression of mRNA coding for 5 xenobiotic transporters in mammary tissue isolated from lactating dairy cows, primary epithelial cells isolated from these tissues and cultured in T25 flasks or as polarized monolayers on permeable supports, and BME‐UV cells cultured as polarized monolayers on permeable supports. 18S rRNA was employed as an internal standard for comparison. Relative to the native tissue, the expression of mRNA coding for ABCB1 and NCBT1 were increased in all the cell cultures, whereas ABCG2 and OATPD mRNA expression were reduced. The expression of OCT1 mRNA remained unchanged. These initial results suggest that standard culture conditions promote the expression of putative drug transport proteins in proportions and levels that do not directly reflect those observed in the actively lactating dam. Further studies are needed to refine culture conditions for these potential in vitro models. [NIH P20‐RR017686 Core C]

Effect of calf presence during milking on milk fatty acid profile in Prim'Holstein and Salers cow breeds.

The present study was conducted in order to evaluate the effects of calf presence during milking and cow breed on milk fatty acid (FA) profile. 30 Prim’Holstein (H) and Salers (S) primiparous lactating cows were milked in the presence (CP) or in the absence (CA) of their calves, during the 9 months of lactation. Milk FA profile was significantly influenced by breed: 4:0, 12:0, 18:2 n-6 and cis-18:1 had higher concentrations in milk from H cows, whereas 14:0, 18:3 n-3, cis-9,trans-11-CLA and trans-18:1 had higher concentrations in milk from S cows. The presence of the calf during milking also had an important effect: it decreased the milk fat content, as well as 18:0, 18:2 n-6, 18:3 n-3 and trans-18:1 levels and it increased 16:0 level. Cis-9,trans-11-CLA concentration increased in the presence of the calf, for H cows, whereas it decreased for S cows.

Effect of Calf Presence During Milking on Milk Fatty Acid Profile in Prim’Holstein and Salers Cow Breeds

The present study was conducted in order to evaluate the effects of calf presence during milking and cow breed on milk fatty acid (FA) profile. 30 Prim’Holstein (H) and Salers (S) primiparous lactating cows were milked in the presence (CP) or in the absence (CA) of their calves, during the 9 months of lactation. Milk FA profile was significantly influenced by breed: 4:0, 12:0, 18:2 n-6 and cis-18:1 had higher concentrations in milk from H cows, whereas 14:0, 18:3 n-3, cis-9,trans-11-CLA and trans-18:1 had higher concentrations in milk from S cows. The presence of the calf during milking also had an important effect: it decreased the milk fat content, as well as 18:0, 18:2 n-6, 18:3 n-3 and trans-18:1 levels and it increased 16:0 level. Cis-9,trans-11-CLA concentration increased in the presence of the calf, for H cows, whereas it decreased for S cows.

The controlled release of tilmicosin from silica nanoparticles

The aim of this study was to use silica nanoparticles as the carrier for controlled release of tilmicosin. Tilmicosin was selected as a drug model molecule because it has a lengthy elimination half-life and a high concentration in milk after subcutaneous administration. Three samples of tilmicosin-loaded silica nanoparticles were prepared with different drug-loading weight. The drug-loading weight in three samples, as measured by thermal gravimetric analysis, was 29%, 42%, and 64%, respectively. With increased drug-loading weight, the average diameter of the drug-loaded silica nanoparticles was increased from 13.4 to 25.7 nm, and the zeta potential changed from−30.62 to−6.78 mV, indicating that the stability of the drug-loaded particles in the aqueous solution decreases as drug-loading weight increases. In vitro release studies in phosphate-buffered saline showed the sample with 29% drug loading had a slow and sustained drug release, reaching 44% after 72 h. The release rate rose with increased drug-loading weight; therefore, the release of tilmicosin from silica nanoparticles was well-controlled by adjusting the drug loading. Finally, kinetics analysis suggested that drug released from silica nanoparticles was mainly a diffusion-controlled process.

Partitioning of polybrominated diphenyl ethers (PBDEs) in serum and milk from the same mothers

We and others have previously described partitioning of chemicals, including polychlorinated- p-dioxins, dibenzofurans, and biphenyls in different types of human tissues and fluids, including blood and milk. Additionally, we previously reported the blood to milk partitioning of polybrominated diphenyl ethers (PBDEs) in a group of 11 women. Partitioning is of importance in understanding the toxicokinetics of these compounds and also in clinical medicine in improving estimates of levels in different matrices including blood and milk. In this study we extend these findings, describing the levels of PBDEs detected in the serum and milk of 29 women from Texas. The median sum of the levels of the four most detected congeners (BDE 47, 99, 100, and 153) in serum was 27.8 ng g −1 lipid (range 6.7–501.6 ng g −1 lipid). In milk, the median sum of the levels of the same congeners was 39.7 ng g −1 lipid (range 12.9–580.3 ng g −1 lipid). The levels detected in breast milk in this study are similar to those we reported in 2003, where a median total PBDE level of 34 ng g −1 lipid was reported. When congener specific blood to milk partitioning ratios were calculated for BDEs 47, 99, 100, and 153, the relatively small tetrabrominated congener, BDE 47, was found in higher concentrations in milk compared to blood, while the higher molecular weight hexabrominated congener, BDE 153, was found in approximately equal quantities in blood and milk, on a lipid normalized basis. The reason for the differential partitioning of PBDE congeners in milk and blood could be due to variation in toxicokinetics, specifically distribution based on molecular size or molecular weight.

Effect of Albendazole Administration on Pharmacokinetic Aspects of Tylosin in Lactating Goats

Tylosin concentrations and its disposition kinetics in serum, urine, and milk of lactating goats following a single intravenous (i.v.) or intramuscular (i.m.) injection (10 mg kg(-1) b.wt.) were carried out using high performance liquid chromatography (HPLC).The concentration-time curve of tylosin after i.v. injection could be described by a two-compartment open model. Tylosin was rapidly distributed and eliminated from goat's bodies with t(1/2(beta)) value of 1.25 h. The V((d)) was less than one litre/kg and the MRT was 1.40 h. Concomitant administration with albendazole decreased tylosin concentrations in serum after its i.v. injection and the MRT was 1.17 h. The AUC and AUMC showed a significant decrease in goats given albendazole prior to injection as compared with those given tylosin only. Following i.m. administration, the absorption half-life and the corresponding t(max) revealed rapid absorption rate with systemic bioavailability (F%) of 76.2 %. Albendazole when given concurrently with tylosin decreased its serum concentrations due to lower bioavailability (43.25 %). Following i.v. or i.m. injection, tylosin was excreted rapidly in urine in concentration much higher than those determined in serum and milk. Tylosin administered in goats pretreated with albendazole was excreted at lower concentration in urine, with a significant decrease from 1(st) to 10(th) hours as compared with animals given tylosin only. Following i.v. or i.m. administration of tylosin, the drug was excreted in high concentrations in milk. A significant decrease in milk concentrations was reported in goats pretreated with albendazole.