Mammary and Renal Excretion of Sulphadoxine and Trimethoprim in Cows

DAVITIYANANDA, DANIS and FOLKE RASMUSSEN: Mammary and renal excretion of sulphadoxine and trimethoprim in cows. Acta vet. scand. 1974, 15, 340–355. — In 21 experiments on 5 healthy, nonpregnant cows are sulphadoxine and trimethoprim infused intravenously for maintenance of constant levels of the drugs through the experimental periods. The experiments show that both sulphadoxine and trimethoprim are bound to the proteins in blood plasma and milk. Further it is demonstrated that sulphadoxine (an acid) is excreted into milk in concentrations lower than in blood plasma while trimethoprim (a base) is excreted into milk in concentrations higher than in blood plasma. Both results are consistent with the theory that drugs are excreted through the mammary gland by passive diffusion. Glomerular filtration and back-diffusion are both involved in the renal handling of sulphadoxine and trimethoprim. For trimethoprim active tubular secretion is also demonstrated. Both the mammary and renal handling of sulphadoxine as well as trimethoprim are influenced by the pH of milk and urine, respectively. The experiments underline that it is the unionized, non-protein-bound fraction of the drugs which diffuses through biological membranes. sulphadoxine; trimethoprim; mammary excretion; renal excretion; cow.     

Culturable psychrotrophic bacterial communities in raw milk and their proteolytic and lipolytic traits

During cold storage after milk collection, psychrotrophic bacterial populations dominate the microflora, and their extracellular enzymes, mainly proteases and lipases, contribute to the spoilage of dairy products. The diversity, dynamics, and enzymatic traits of culturable psychrotrophs in raw milk from four farms were investigated over a 10-month period. About 20% of the isolates were found to be novel species, indicating that there is still much to be learned about culturable psychrotrophs in raw milk. The psychrotrophic isolates were identified and classified in seven classes. Three classes were predominant, with high species richness (18 to 21 species per class) in different seasons of the year: Gammaproteobacteria in spring and winter, Bacilli in summer, and Actinobacteria in autumn. The four minor classes were Alphaproteobacteria, Betaproteobacteria, Flavobacteria, and Sphingobacteria. The dominant classes were found in all four dairies, although every dairy had its own unique "bacterial profile." Most but not all bacterial isolates had either lipolytic or both lipolytic and proteolytic activities. Only a few isolates showed proteolytic activity alone. The dominant genera, Pseudomonas and Acinetobacter (Gammaproteobacteria), showed mainly lipolytic activity, Microbacterium (Actinobacteria) was highly lipolytic and proteolytic, and the lactic acid bacteria (Lactococcus and Leuconostoc) displayed very minor enzymatic ability. Hence, the composition of psychrotrophic bacterial flora in raw milk has an important role in the determination of milk quality. Monitoring the dominant psychrotrophic species responsible for the production of heat-stable proteolytic and lipolytic enzymes offers a sensitive and efficient tool for maintaining better milk quality in the milk industry.     

Safety of milk and milk derivatives in relation to BSE: the lactoferrin example

Bovine Spongiform Encephalopathy (BSE) belongs to Transmissible Spongiform Encephalopathies (TSEs) or Prion diseases. BSE is a feed borne infection of cattle. Epidemiological and laboratory data suggest that the BSE infectious agent is responsible for the variant form of Creutzfeldt-Jakob Disease (vCJD) and that the oral route is the most plausible way of infection. Therefore there is concern that the BSE agent can be transmitted to humans by biological materials (i.e. meat products, blood, milk) from susceptible BSE animal species (mostly cows but possibly, sheep and goats). Lactoferrin (LF) can be produced by purification from large volumes of cow's milk or whey. Therefore, a potential BSE risk for milk and milk products needs to be evaluated by risk assessment. The Committee for proprietary Medicinal Products--CPMP of the European Commission and the WHO have categorized risk tissues from TSE susceptible ruminant species in different classes in relation to the BSE risk for medicinal products. Milk, colostrum, and tissues of the mammary gland have been classified in the category of no detectable infectivity. A secondary contamination of milk can be virtually excluded (i.e. milk is taken from living animals). In the light of current scientific knowledge and irrespective of the geographical origin, milk and milk derivatives (e.g. lactoferrin, lactose) are unlikely to present any risk of TSE contamination provided that milk is sourced from healthy animals in the same conditions as milk collected from human consumption. So the risk of milk and milk derivatives in relation to BSE is negligible.     

Chemical composition of the membranes of fat globules of cow's milk

The methods of microthin-layer chromatography on plates with silica gel and disc-electrophoresis in PAAG are used to determine the lipid and protein composition of fat globule membranes of cow milk on the first (foremilk) and the tenth day (milk) of lactation as well as of the buttermilk, a by-product of the technological processing of milk. Differences are found in the quantitative content of the basic classes of lipids and proteins in membranes of fat globules produced from foremilk and milk of cows. The membranes of buttermilk and milk fat globules are characterized by the identical qualitative and similar quantitative chemical composition, that permits using buttermilk as easily available and rich source of components from membranes of cow milk fat globules in the first place of phospholipids and sterols.     

High-performance liquid chromatography method for the simultaneous determination of sulfamethoxazole and trimethoprim in bovine milk using an on-line clean-up column

A bidimensional HPLC method for the simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in bovine milk has been developed and validated. After centrifugation, aliquots (150 microl) of milk samples were directly injected to a column-switching HPLC system. At the first step a RAM octyl-BSA column was employed to automatically remove proteins that otherwise would interfere with milk analysis. The mobile phase 0.01 M phosphate buffer pH 6.0:acetonitrile (95:5, v/v) was used in the first 5 min for the elution of milk proteins and then 0.01 M phosphate buffer pH 6.0:acetonitrile (83:17, v/v) for transfer SMX and TMP to the analytical column. The separation of SMX and TMP from one another and from other remaining milk components was performed on an octyl column using the mobile phase 0.01 M phosphate buffer pH 5.0:acetonitrile (82:18, v/v), which were detected by UV at 265 nm. The calibration graphs were linear in the concentration ranges of 25-800 ng/ml and 50-400 ng/ml for SMX and TMP, respectively. The intra- and inter-assay coefficients of variation were less than 15% for both drugs. The validated method was applied to the analysis of milk samples of twelve (two groups of six) cows after administration (intramuscular or subcutaneous) of a single recommended therapeutic dose of the SMX-TMP combination.     

Available lysine content in human milk: stability during manipulation prior to ingestion

Available lysine content is an indicator of protein quality and nutritional value of milk. Many studies have examined the effects of extraction, treatment and storage of human milk upon its components, though no references are found regarding the possible changes in milk quality as defined by its content in essential amino acids such as lysine. The present study investigates the available lysine content in human milk and the variations in lysine resulting from milk manipulation as follows: (a) Cold storage (refrigeration at 4 degrees C for 48 hours, and frozen for 15 days at -20 degrees C); (b) Thermal treatment under conditions of low (Holder)(63 degrees C/30 minutes) and high pasteurization (75 degrees C/15 seconds). The results obtained show a decrease in milk lysine concentration after storage in both refrigerated and frozen samples. Pasteurization causes a highly significant loss of available lysine. The lysine losses were greater on applying low pasteurization versus the more gentle conditions of high pasteurization. CONCLUSIONS: While manipulation through cold storage or thermal treatment does not affect the protein content of human milk, its protein quality is modified. When human milk must be subjected to hygienization, it is preferable to apply high temperature treatment (75 degrees C, 15 seconds) than habitual pasteurization (63 degrees C, 30 minutes).     

Adverse effects associated with selective serotonin reuptake inhibitors and tricyclic antidepressants: a meta-analysis

BACKGROUND: The use of antidepressant medications and the resulting costs have increased dramatically in recent years, partly because of the introduction of selective serotonin reuptake inhibitors (SSRIs). An assessment of the clinical and economic aspects of SSRIs compared with the older tricyclic antidepressants (TCAs) was initiated to generate information for purchasers of these drugs as well as clinicians. One component of this study was an examination of the adverse effects associated with the use of these drugs. METHODS: Searches of bibliographic databases (for January 1980 through May 1996) and manual scanning of both peer-reviewed publications and other documents were used to identify double-blind, randomized controlled trials involving at least one SSRI and one TCA. For the study of adverse effects, only trials that had at least 20 patients in each trial arm and that reported rates of adverse effects in both arms were retained. In total 84 trials reporting on 18 adverse effects were available. Meta-analyses were undertaken to calculate pooled differences in rates of adverse effects. The question of whether the method of eliciting information from patients about adverse effects made a difference in the findings was also examined. Finally, differences in drop-out rates due to adverse effects were calculated. RESULTS: The crude rates of occurrence of adverse effects ranged from 4% (palpitations) to 26% (nausea) for SSRIs and from 4% (diarrhea) to 27% (dry mouth) for TCAs. The differences in the rates of adverse effects between the 2 types of drugs ranged from 14% more with SSRIs (for nausea) to 11% more with TCAs (for constipation). The results did not depend on the method of eliciting information from patients. There were no statistically significant differences between drug classes in terms of drop-outs due to adverse effects. INTERPRETATION: SSRIs and TCAs are both associated with adverse effects, although the key effects differ between the drug classes. Further explanation of the adverse effects and their relation to discontinuation of medication will require better studies involving prospective collection of quality-of-life data.     

Thiourea, triazole and thiadiazine compounds and their metal complexes as antifungal agents

Many currently available antifungal and antibacterial agents have undesirable toxic effects, and a wide spread use of these drugs has lead to rapid development of drug resistant strains which are the leading cause for treatment failure in both clinical and agricultural applications. The present article provides a synopsis of recent progress in investigations of new classes of antifungal compounds: disubstituted aliphatic and aromatic thioureas, triazole and thiazine compounds which act as ligands for transition metals. Antifungal effects of these compounds and selected metallic complexes versus representative plant pathogenic fungi are reviewed.     

Effect of two long acting injectable progestogens on lactation in the human.

The effects of Depoprovera and Deladroxone were studied in humans, on certain milk components as well as on the growth of the nursed infants. Both drugs caused reduction in milk yield. Both drugs caused an increase in the concentration of milk total proteins, however. Depoprovera caused an increase while Deladroxone caused a decrease in the total amount of milk proteins per feed. Depoprovera showed no effect while Deladroxone caused an increase in the concentration of milk lipids; however, both drugs caused reduction in the total amount of milk lipids per feed. Both drugs showed no effect on the concentration of milk lactose, but caused reduction in the total amount of milk lactose per feed. The percentage increase in weight of nursed infants was decreased by Depoprovera, but not affected by Deladroxone.     

Comparison of the sensitivity of manual and automated immunomagnetic separation methods for detection of Shiga toxin-producing Escherichia coli O157:H7 in milk

AIM: To determine the sensitivity of methods for detection of injured and uninjured Escherichia coli O157:H7 (E. coli O157) in raw and pasteurized milk. METHODS AND RESULTS: Raw milk, pasteurized milk with 1.5% fat content and pasteurized milk with 3.5% fat content were spiked with E. coli O157 at low levels. The samples were enriched in modified tryptone soya broth with novobiocin (mTSBn) at 37 degrees C. Aliquots of the enriched culture were analysed either by manual immunomagnetic separation (MIMS) and culturing on sorbitol MacConkey agar with or without cefixime and potassium tellurite (SMACct or SMAC), or by automated immunomagnetic separation and integrated ELISA (EiaFosstrade mark). Uninjured E. coli O157 organisms were detected in milk by both methods at 1 cfu 10 ml-1 sample). Injured organisms were detected at levels of about 4 cfu 10 ml-1 sample. Direct enrichment in mTSBn (22 h incubation) showed better sensitivity for injured cells than enrichment in buffered peptone water (BPW, 22 h incubation), or in a two-step enrichment consisting of BPW (6 h, 37 degrees C) and mTSBn (16 h, 37 degrees C), successively. CONCLUSIONS: The methods showed equal sensitivity in that they were both able to detect 1 cfu 10 ml-1 milk sample. Injured organisms can be detected and isolated at a level almost as low as this. A resuscitation step is not recommended for the detection and isolation of injured and non-injured E. coli O157 from milk. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to the dilution of contamination in the bulk tank, analysis of milk for the presence of E. coli O157 requires a very sensitive method. Both methods described here are useful for such analysis.     

Proteome mapping of human skim milk proteins in term and preterm milk

The abundant proteins in human milk have been well characterized and are known to provide nutritional, protective, and developmental advantages to both term and preterm infants. However, relatively little is known about the expression of the low abundance proteins that are present in human milk because of the technical difficulties associated with their detection. We used a combination of electrophoretic techniques, ProteoMiner treatment, and two-dimensional liquid chromatography to examine the proteome of human skim milk expressed between 7 and 28 days postpartum by healthy term mothers and identified 415 in a pooled milk sample. Of these, 261 were found in human skim milk for the first time, greatly expanding our understanding of the human skim milk proteome. The majority of the proteins identified were involved in either the immune response (24%) or in cellular (28%) or protein (16%) metabolism. We also used iTRAQ analysis to examine the effects of premature delivery on milk protein composition. Differences in protein expression between pooled milk from mothers delivering at term (38-41 weeks gestation) and preterm (28-32 weeks gestation) were investigated, with 55 proteins found to be differentially expressed with at least 90% confidence. Twenty-eight proteins were present at higher levels in preterm milk, and 27 were present at higher levels in term milk.     

Lacto-N-tetraose, fucosylation, and secretor status are highly variable in human milk oligosaccharides from women delivering preterm

Breast milk is the ideal nutrition for term infants but must be supplemented to provide adequate growth for most premature infants. Human milk oligosaccharides (HMOs) are remarkably abundant and diverse in breast milk and yet provide no nutritive value to the infant. HMOs appear to have at least two major functions: prebiotic activity (stimulation of the growth of commensal bacteria in the gut) and protection against pathogens. Investigations of HMOs in milk from women delivering preterm have been limited. We present the first detailed mass spectrometric analysis of the fucosylation and sialylation in HMOs in serial specimens of milk from 15 women delivering preterm and 7 women delivering at term using nanohigh performance liquid chromatography chip/time-of-flight mass spectrometry. A mixed-effects model with Levene's test was used for the statistical analyses. We find that lacto-N-tetraose, a core HMO, is both more abundant and more highly variable in the milk of women delivering preterm. Furthermore, fucosylation in preterm milk is not as well regulated as in term milk, resulting in higher within and between mother variation in women delivering preterm vs term. Of particular clinical interest, the α1,2-linked fucosylated oligosaccharide 2'-fucosyllactose, an indicator of secretor status, is not consistently present across lactation of several mothers that delivered preterm. The immaturity of HMO production does not appear to resolve over the time of lactation and may have relevance to the susceptibility of premature infants to necrotizing enterocolitis, late onset sepsis, and related neurodevelopmental impairments.     

Modelling mammary metabolism in the dairy cow to predict milk constituent yield, with emphasis on amino acid metabolism and milk protein production: model construction

Previous efforts to simulate mammary metabolism have focused on energy, mostly considering amino acids (AA) in aggregate. The main objective of this work was to build a model of mammary metabolism, based on data from arterio-venous difference studies, which considered AA in sufficient detail to predict yields of milk solids. The model contains 19 state variables and considers the removal of 37 metabolites from blood, including 22 AA. It is driven by blood flow and arterial concentrations, and outputs include milk protein, milk lactose, and three classes of milk fat (by chain length). The model was parameterized using a balance version of it and the mean observations from four arterio-venous difference experiments, with a limited number of assumptions, and evaluated against these experiments. In assembling the balance model, milk protein output was not predicted satisfactorily, as some essential AA were not present in quantities great enough to support the rates of milk protein synthesis observed experimentally. Tryptophan showed the greatest deficit, followed by tyrosine plus phenylalanine, methionine, and histidine. In addition, significant quantities of pyruvate were needed to synthesize serine, glycine, and alanine. The supply of alpha-ketoglutarate plus glutamate to synthesize proline and glutamine was provided in part by catabolism of arginine; the remainder was derived from catabolism of other AA and energetic substrates.     

Genetic parameters for endocrine and traditional fertility traits,hyperketonemia and milk yield in dairy cattle

High-yielding cows may suffer from negative energy balance during early lactation, which can lead to ketosis and delayed ability of returning to cyclicity after calving. Fast recovery after calving is essential when breeding for improved fertility. Traditionally used fertility traits, such as the interval from calving to first insemination (CFI), have low heritabilities and are highly influenced by management decisions. Herd Navigator™ management program samples and analyses milk progesterone and β-hydroxybutyrate (BHB) automatically during milking. In this study, the genetic parameters of endocrine fertility traits (measured from milk progesterone) and hyperketonemia (measured from milk BHB) in early lactation were evaluated and compared with traditional fertility traits (CFI, interval from calving to the last insemination and interval from first to last insemination) and the milk yield in red dairy cattle herds in Finland. Data included observations from 14 farms from 2014 to 2017. Data were analyzed with linear animal models using DMU software and analyses were done for first parity cows. Heritability estimates for traditional fertility traits were low and varied between 0.03 and 0.07. Estimated heritabilities for endocrine fertility traits (interval from calving to the first heat (CFH) and commencement of luteal activity (C-LA)) were higher than for traditional fertility traits (0.19 to 0.33). Five slightly different hyperketonemia traits divided into two or three classes were studied. Linear model heritability estimates for hyperketonemia traits were low, however, when the threshold model was used for binary traits the estimates became slightly higher (0.07 to 0.15). Genetic correlation between CFH and C-LA for first parity cows was high (0.97) as expected since traits are quite similar. Moderate genetic correlations (0.47 to 0.52) were found between the endocrine fertility traits and early lactation milk yield. Results suggest that the data on endocrine fertility traits measured by automatic systems is a promising tool for improving fertility, specifically when more data is available. For hyperketonemia traits, dividing values into three classes instead of two seemed to work better. Based on the current study and previous studies, where higher heritabilities have been found for milk BHB traits than for clinical ketosis, milk BHB traits are a promising indicator trait for resistance to ketosis and should be studied more. It is important that this kind of data from automatic devices is made available to recording and breeding organizations in the future.     

Comparison of the human and bovine milk N-glycome via high-performance microfluidic chip liquid chromatography and tandem mass spectrometry

The isolation of whey proteins from human and bovine milks followed by profiling of their entire N-glycan repertoire is described. Whey proteins resulting from centrifugation and ethanol precipitation of milk were treated with PNGase F to release protein-bound N-glycans. Once released, N-glycans were analyzed via nanoflow liquid chromatography coupled with quadrupole time-of-flight mass spectrometry following chromatographic separation on a porous graphitized carbon chip. In all, 38 N-glycan compositions were observed in the human milk sample while the bovine milk sample revealed 51 N-glycan compositions. These numbers translate to over a hundred compounds when isomers are considered and point to the complexity of the mixture. High mannose, neutral, and sialylated complex/hybrid glycans were observed in both milk sources. Although NeuAc sialylation was observed in both milk samples, the NeuGc residue was only observed in bovine milk and marks a major difference between human and bovine milks. To the best of our knowledge, this study is the first MS based confirmation of NeuGc in milk protein bound glycans as well as the first comprehensive N-glycan profile of bovine milk proteins. Tandem MS was necessary for resolving complications presented by the fact that (NeuGc:Fuc) corresponds to the exact mass of (NeuAc:Hex). Comparison of the relative distribution of the different glycan types in both milk sources was possible via their abundances. While the human milk analysis revealed a 6% high mannose, 57% sialylation, and 75% fucosylation distribution, a 10% high mannose, 68% sialylation, and 31% fucosylation distribution was observed in the bovine milk analysis. Comparison with the free milk oligosaccharides yielded low sialylation and high fucosylation in human, while high sialylation and low fucosylation are found in bovine. The results suggest that high fucosylation is a general trait in human, while high sialylation and low fucosylation are general features of glycosylation in bovine milk.     

Determination of domperidone in human serum and human breast milk by high-performance liquid chromatography–electrospray mass spectrometry

A sensitive and selective method for the determination of domperidone in human breast milk and serum has been developed. The same method may be successfully applied to both matrices to a lower limit of quantitation of 0.5 ng/ml. Samples are processed by a liquid–liquid extraction, and analyzed by LC–ESI-MS in positive ion mode. There was no interference, on the domperidone quantitation, from over 30 drugs. Samples from patients, at various times post-dose, were analyzed and a large number showed significant levels of domperidone in the breast milk as well as in the serum.     

Do established SNPs affecting bovine milk traits exist in other dairy ruminants?

To assess whether established single nucleotide polymorphisms (SNPs) affecting bovine milk traits are present in small ruminants, we genotyped samples from Chios and Cyprus fat-tailed sheep, as well as Damascus and Machaeras goats for the presence of the acylCoA:diacylglycerol acyltransferase 1 (DGAT1) K232A and the growth hormone receptor (GHR) F279Y SNPs. Both of these SNPs have been previously well documented in cattle as having strong effects on milk yield and composition and have been postulated as being the causative mutations to partially explain QTLs identified on bovine chromosomes 14 and 20. Although we were able to confirm the presence of both of these mutations in bovine sample controls by both allele specific PCR reactions and direct DNA sequencing, we were unable to detect them in any of the four major pure breeds of sheep and goats supporting the dairy industry of Cyprus.     

Glycoproteomics of milk: differences in sugar epitopes on human and bovine milk fat globule membranes

Oligosaccharides from human and bovine milk fat globule membranes were analyzed by LC-MS and LC-MS/MS. Global release of N-linked and O-linked oligosaccharides showed both to be highly sialylated, with bovine peak-lactating milk O-linked oligosaccharides presenting as mono- and disialylated core 1 oligosaccharides (Galbeta1-3GalNAcol), while human milk had core type 2 oligosaccharides (Galbeta1-3(GlcNAcbeta1-6)GalNAcol) with sialylation on the C-3 branch. The C-6 branch of these structures was extended with branched and unbranched N-acetyllactosamine units terminating in blood group H and Lewis type epitopes. These epitopes were also presented on the reducing terminus of the human, but not the bovine, N-linked oligosaccharides. The O-linked structures were found to be attached to the high molecular mass mucins isolated by agarose-polyacrylamide composite gel electrophoresis, where MUC1 and MUC4 were present. Analysis of bovine colostrum showed that O-linked core 2 oligosaccharides are present at the early stage (3 days after birth) but are down-regulated as lactation develops. This data indicates that human milk may provide different innate immune protection against pathogens compared to bovine milk, as evidenced by the presence of Lewis b epitope, a target for the Helicobacter pylori bacteria, on human, but not bovine, milk fat globule membrane mucins. In addition, non-mucin-type O-linked fucosylated oligosaccharides were found (NeuAc-Gal-GlcNAc1-3Fuc-ol in bovine milk and Gal-GlcNAc1-3Fuc-ol in human milk). The O-linked fucose structure in human milk is the first to our knowledge to be found on high molecular mass mucin-type molecules.     

Dynamic modeling of Listeria monocytogenes growth in pasteurized milk

AIMS: The development and validation of a dynamic model for predicting Listeria monocytogenes growth in pasteurized milk stored at both static and dynamic temperature conditions. METHODS AND RESULTS: Growth of inoculated L. monocytogenes in a commercial pasteurized whole milk product was monitored at various isothermal conditions from 1.5 to 16 degrees C. The kinetic parameters of the pathogen were modelled as a function of temperature using a square root type model, which was further validated using data from 92 published growth curves from eight different milk products. Compared to four published models for L. monocytogenes growth, the model developed in this study performed better, with a per cent discrepancy and bias of 49.1 and -1.01%, respectively. The performance of the model in predicting growth at dynamic temperature conditions was evaluated at four different fluctuating temperature scenarios with periodic temperature changes from -2 to 16 degrees C. The prediction of growth at dynamic storage temperature was based on the square root model in conjunction with the differential equations of the Baranyi and Roberts model, which were numerically integrated with respect to time. The per cent relative errors between the observed and the predicted growth of L. monocytogenes were less than 10% for all temperature scenarios tested. CONCLUSIONS: Available models from experiments conducted in laboratory media may result in significant overestimation of L. monocytogenes growth in pasteurized milk because they do not take into account factors such as milk composition (e.g. natural antimicrobial compounds present in milk) and the interactions of the pathogen with the natural microflora. The product-targeted model developed in the present study showed a high performance in predicting growth of L. monocytogenes in pasteurized milk under both static and dynamic temperature conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Temperature fluctuations often occur during the transportation and storage of pasteurized milk. A high performance, dynamic model for the growth of L. monocytogenes can be a useful tool for effective management and optimization of product safety and can lead to more realistic estimations of pasteurized-milk related safety risks.