Transporters dynamically expressed at the mammary gland transport critical nutrients into the breast milk of nursing mothers to meet the nutritional demands of the suckling infant. However, xenobiotics may interact with these transporters to potentially alter the nutrient composition of milk and compromise neonatal nutrition. The aim of the present study was to quantitatively evaluate the constitutive expression of various nutrient transporters in whole mammary gland tissue and mammary epithelial organoids (MEO) isolated from female Sprague-Dawley rats at various stages of pregnancy, lactation, and involution. Furthermore, the studys aim was to determine if appropriately cultured mammary epithelial organoids (MEO) maintain in vivo transporter expression to lay down critical groundwork for the development of an in vitro screening tool assessing xenobiotic-nutrient transporter interactions. The following transporters were evaluated using quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR): multidrug resistance protein (Mdr) 1a, 1b; multidrug resistance-like protein (Mrp) 1; organic cation transporter (Oct) 1; organic cation/carnitine transporter (Octn) 1, 2, and 3; concentrative nucleoside transporter (Cnt) 1, 2, and 3; equilibrative nucleoside transporter (Ent) 1, 2, and 3; nucleobase transporter (Ncbt) 1 and 2; oligopeptide transporter (Pept) 1 and 2; methotrexate carrier (Mtx) 1; divalent metal transporter (Dmt) 1; and the milk protein ?-casein. Transporter expression patterns in MEO differed from whole tissue for ?-actin, Mdr1a, Mdr1b, Oct1, Octn3, Ent3, Cnt1, Cnt3, Ncbt1, Pept2, Mtx1, and ?-casein. This brings into question whether whole mammary gland tissue is truly appropriate for an understanding of transporter expression in the mammary epithelium. Nevertheless, four general transporter expression patterns emerged in isolated MEO: decline throughout lactation (Mdr1a, Mdr1b, Mrp1 & Dmt1), increase throughout lactation (Cnt1 & Octn3), increase in early lactation (Oct1, Octn2, Ent1, Cnt2, Cnt3, Pept2 & Mtx1) and constant expression throughout lactation (Octn1, Ent2, Ent3, Ncbt1, Ncbt2 & Pept1). These expression patterns will provide insight into the critical windows of nutrient delivery to the breast milk to provide adequate nutritional stimuli to the suckling infant. Furthermore, MEO cultured in an extracellular matrix-rich environment maintained transporter expression at the mRNA level, which underscores the potential of the primary MEO in vitro model system as a screening tool for xenobiotic-transporter interactions at the mammary gland. Transporter expression patterns in MEO were unique for each transporter evaluated. This information accompanied by an in vitro screening tool may allow for predictions of xenobiotic interference with breast milk composition to help safeguard infant health.

For the polar bear (<i>Ursus maritimus</i>), a terrestrial carnivore on the highest trophic level in the Arctic marine ecosystem, periods of nutritional restriction or fasting are a characteristic feature of an annual cycle. The overall objective of my thesis was to examine some of the effects of such a 'feast-or-fast' feeding pattern on the body composition, body size and reproductive performance of this Holarctic ursid. As a reproductive strategy, pregnant polar bears occupy maternity dens for up to 6 months between late summer and spring. While in dens, maternal nutrient stores meet all maintenance energy requirements and sustain the nutritional demands of gestation and early lactation. I quantified the nutritional costs of this prolonged 'reproductive fast' in polar bears and examined the effects of variation in maternal body condition on reproductive performance. While fasting, body mass decreased by 43% and of the change in body energy content 93% was attributable to loss of fat. Bears that were fatter priorto denning produced heavier cubs, which would be more likely to survive. Much of the variation in body condition prior to denning was accounted for by age, older females being in better condition. Using an index of milk quality that was closely related to daily milk energy yield, I investigated the independent effects of maternal body condition and age on lactation. Irrespective of condition, older bears tended to produce higher quality milk. While lactation in polar bears is clearly sensitive to body condition, these results also provide strong support for an age-specific increase in reproductive effort among females. Body size is typically a strong determinant of male reproductive success in polygynous mammals such as polar bears. Consequently, theory predicts that mothers in good condition should invest more in male than female offspring in-order to produce large adult males. An underlying assumption of this theory, however, is that early differences in body size among male offspring, such as those apparent by the end of maternal care, will affect their relative adult body size. I tested the validity of this assumption in polar bears and found that, in comparison to females, variation in body size among 2-year-old males was a weak determinant of adult size. I suggest that, in comparison to females, a longer period of growth after maternal care may predispose the adult size of males to a greater degree of environmentally mediated variation. This lack of persistence in relative body size would limit the ability of mothers to affect the adult size of their male offspring, and thus reduce the effectiveness of sex-biased maternal investment as a reproductive strategy in polar bears. One of the principle physiological adaptations enabling animals to go without food for prolonged periods seems to be a heightened ability to minimize the net catabolism of body protein. I quantified changes in the body composition of free-ranging polar bears during the ice-free season. In contrast to previous studies on fasting bears, catabolism of protein appeared to meet a significant proportion of maintenance energy demands in some individuals. (Abstract shortened by UMI.)

Transporters dynamically expressed at the mammary gland transport critical nutrients into the breast milk of nursing mothers to meet the nutritional demands of the suckling infant. However, xenobiotics may interact with these transporters to potentially alter the nutrient composition of milk and compromise neonatal nutrition. The aim of the present study was to quantitatively evaluate the constitutive expression of various nutrient transporters in whole mammary gland tissue and mammary epithelial organoids (MEO) isolated from female Sprague-Dawley rats at various stages of pregnancy, lactation, and involution. Furthermore, the studys aim was to determine if appropriately cultured mammary epithelial organoids (MEO) maintain in vivo transporter expression to lay down critical groundwork for the development of an in vitro screening tool assessing xenobiotic-nutrient transporter interactions. The following transporters were evaluated using quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR): multidrug resistance protein (Mdr) 1a, 1b; multidrug resistance-like protein (Mrp) 1; organic cation transporter (Oct) 1; organic cation/carnitine transporter (Octn) 1, 2, and 3; concentrative nucleoside transporter (Cnt) 1, 2, and 3; equilibrative nucleoside transporter (Ent) 1, 2, and 3; nucleobase transporter (Ncbt) 1 and 2; oligopeptide transporter (Pept) 1 and 2; methotrexate carrier (Mtx) 1; divalent metal transporter (Dmt) 1; and the milk protein ?-casein. Transporter expression patterns in MEO differed from whole tissue for ?-actin, Mdr1a, Mdr1b, Oct1, Octn3, Ent3, Cnt1, Cnt3, Ncbt1, Pept2, Mtx1, and ?-casein. This brings into question whether whole mammary gland tissue is truly appropriate for an understanding of transporter expression in the mammary epithelium. Nevertheless, four general transporter expression patterns emerged in isolated MEO: decline throughout lactation (Mdr1a, Mdr1b, Mrp1 & Dmt1), increase throughout lactation (Cnt1 & Octn3), increase in early lactation (Oct1, Octn2, Ent1, Cnt2, Cnt3, Pept2 & Mtx1) and constant expression throughout lactation (Octn1, Ent2, Ent3, Ncbt1, Ncbt2 & Pept1). These expression patterns will provide insight into the critical windows of nutrient delivery to the breast milk to provide adequate nutritional stimuli to the suckling infant. Furthermore, MEO cultured in an extracellular matrix-rich environment maintained transporter expression at the mRNA level, which underscores the potential of the primary MEO in vitro model system as a screening tool for xenobiotic-transporter interactions at the mammary gland. Transporter expression patterns in MEO were unique for each transporter evaluated. This information accompanied by an in vitro screening tool may allow for predictions of xenobiotic interference with breast milk composition to help safeguard infant health.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2009. / Härtill 4 uppsatser.

Breastfeeding support for mothers and their babies historically was the informal work of family and community members. In the United States today, breastfeeding support is embedded in the biomedical system, and is provided by a new allied health professional: the International Board Certified Lactation Consultant (IBCLC). This dissertation explores this professionalization of breastfeeding support and the origins of this new profession. It studies how IBCLCs working in the U.S. cultural context perceive and practice the profession and examines the relationship between the profession of lactation consulting and the medicalization of breastfeeding. Oral history interviews with 17 founders of the profession, which was established in 1985, and a content analysis of the professional journal (the Journal of Human Lactation) from 1985 to 2010, allowed me to build the story of how and why breastfeeding support became professionalized and how experiential breastfeeding knowledge entered the domain of expert knowledge. While constrained by the biomedical system in which they created the profession, the founders exhibited a both agency and creativity in their production and reproduction of professional values and practices. Interviews with 30 currently certified IBCLCs and observations of the clinical practice of 3 IBCLCs provided insight into the daily practice of IBCLCs working in different settings--hospitals, WIC clinics, pediatric offices, and private practice. The data collected from these ethnographic methods demonstrated how the medical knowledge base of IBCLCs translates into clinical practice with patients, and allowed me to understand the relationship between the profession of lactation consulting and the medicalization of breastfeeding. While IBCLCs' draw on medicalized knowledge and evidence about breastfeeding and human lactation, their interactions with clients are best described as empathetic and humanistic, and are derived from nursing and mother-to-mother breastfeeding support models rather than from a technocratic, biomedical approach to care. While the appropriation of certain biomedical values and standards helped to legitimize the professionalization efforts of the founders, in practice, lactation consultants apply their medical knowledge and clinical experience in a way that reflects the compassionate, empowering care approach of mother-to-mother breastfeeding support and that thus resists the overt medicalization of breastfeeding.

Addressing the sub-optimal breastfeeding initiation and duration rates has become a national priority. Inadequate support for addressing early breastfeeding challenges is compounded by a lack of collaboration between providers such as lactation professionals, nurses, pediatricians, and the family. The purpose of this exploratory study was to understand International Board Certified Lactation Consultants' (IBCLCs) perceived barriers to managing early breastfeeding problems. This qualitative study was guided by the symbolic interactionist framework through a grounded theory methodological approach. In-depth interviews were conducted with 30 IBCLCs from across Florida. IBCLCs were from a range of practice settings, including hospitals, WIC clinics, private practice, and pediatric offices. Data were digitally recorded, transcribed, and analyzed in Atlas.ti. A range of barriers were identified and grouped into the following categories: indirect barriers such as social norms, knowledge, attitudes; direct occupational barriers such as institutional constraints, lack of coordination, and poor service delivery; and direct individual barriers including social support and mother's self-efficacy. A model was developed to illustrate the factors that influence the role enactment of IBCLCs in terms of managing breastfeeding problems. IBCLCs overwhelmingly wish to be perceived as valued members of a health care team, but often find interprofessional collaboration is a struggle. However, IBCLCs find creative strategies to navigate challenges and describe their role as pivotal in empowering mothers and their families to meet their breastfeeding goals. Though rarely actualized, IBCLCs place strong value on coordinated, team approaches to breastfeeding management that employ transparent communication between providers and focus on empowering and educating mothers. Strategies for better collaboration and communication between IBCLCs and other providers are needed. Findings provide insight into the management issues of early breastfeeding problems and may lead to future interventions to reduce early weaning, thus increasing the lifelong health benefits of breastfeeding to the infant and mother.

Darbo tikslas: ištirti praktinio mokymo centro karvių bandos pieno sudėties ir kokybės rodiklių kaitą atskirais laktacijos mėnesiais, sezonais bei keičiantis laikymo sąlygoms. Darbo uždaviniai: 1. Susipažinti su LVA praktinio mokymo ir bandymų centre karvių veislėmis; 2. Išnagrinėti atrinktų karvių grupių pieno kokybės rodiklius ir kokybę, palyginti su atitinkamų veislių Lietuvoje vidurkiu; 3. Išnagrinėti laktacijos mėnesio įtaką pieno kokybės rodikliams; 4. nustatyti sezono įtaką pieno kokybės rodikliams. Išvados: 1. Lietuvos juodmargių įprastinėmis laikymo sąlygomis pieno kiekis buvo 9 % didesnis nei Lietuvos juodmargių, laikomų šaltomis sąlygomis, Vokietijos juodmargių – 22 % didesnis nei tos pačios veislės karvių, laikomų šaltomis sąlygomis, Olandijos juodmargių – 14,9 % didesnis nei tos pačios veislės juodmargių šaltoje karvidėje ir Danijos juodmargių – 7 % didesnis nei tos pačios veislės juodmargių šaltoje karvidėje; 2. Lietuvos juodmargių produktyvumas šalto tipo karvidėje buvo didesnis už kitų juodmargių veislių produktyvumą tomis pačiomis laikymo sąlygomis (14,4 % didesnis už Vokietijos juodmarges, 14,6 % didesnis už Olandijos juodmarges ir 25 % didesnis už Danijos juodmarges). Šis rodiklis demonstruoja Lietuvos juodmargių veislės didesnį atsparumą šalto laikymo sąlygoms; 3. Didžiausias pieno riebalų kiekis (4,63 %) buvo nustatytas Danijos juodmargių karvių piene, laikomų šaltomis sąlygomis; 4. Pieno riebalai ir pieno baltymai kito nepriklausomai nuo laktacijos... [toliau žr. visą tekstą] / Place and methods of work fulfillment: the work was carried out in the Department of Animal Science of Lithuanian Veterinary Academy and Practical Instruction and Research Centre under Lithuanian Veterinary Academy in 2006 – 2008 years of postgraduate studies. 84 cows of equal period of lactation were selected: 58 cows in Muniškiai farm and 26 cows in Giraitė farm. Cows were selected considering that the most producing period of lactation would coincide with cattle-shed period. The conditions of cow keeping are different. In Muniškiai cattle-shed they are kept in standard conditions: they spend time in a pasture in summer and bound to standing places in winter. They are milked in their standing places. Giraitė cattle-shed is of cold type, where cattle are kept loosely. Here cows are kept in cold conditions in groups consisting of 30 – 40 cows. They are herded in a pasture in summer. The cows are milked in Swedish DeLaval “Tandem” type milker. The cows are fed with the same fodder and the schedule of work is also the same. The data has been analyzed statistically using “Excel” spreadsheet. Review of the work: in a period of 2006 – 2007 years milk yield of Lithuanian black-and-white cows was 434 kg less than of German, 768 kg less than of Dutch and 1409 kg less than of Danish black-and-white cows. Lithuanian black-and-white cows provided 25 – 77 kg of butterfat less than Dutch, German or Danish cows. Lithuanian black-and-white cows had proteins 0,05 % less than the same Danish... [to full text]

An experiment was conducted to obtain a hepatic gene expression dataset from postpubertal dairy heifers that could be fit to a computational model capable of predicting future lactation performance values. The initial animal experiment was conducted to characterize the hepatic transcriptional response to 24-hour total feed withdrawal in one-hundred and two postpubertal Holstein dairy heifers using an 8329-gene oligonucleotide microarray in a randomized block design. Plasma concentration of non-esterified fatty acids was significantly higher, while levels of beta-hydroxybutyrate, triacylglycerol, and glucose were significantly lower with the 24-hour total feed withdrawal. In total, 505 differentially expressed genes were identified and microarray results were confirmed by real-time PCR. Upregulation of key gluconeogenic genes occurred despite diminished dietary substrate and lower hepatic glucose synthesis. Downregulation of ketogenic genes was contrary to the non-ruminant response to feed withdrawal, but was consistent with a lower ruminal supply of short-chain fatty acids as precursors. Following the microarray experiment, the first series of regression analyses was employed to identify relationships between gene expression signal and lactation performance measurements taken over the first lactation of 81 of the subjects from the original study. Regression models were evaluated using mean square prediction error (MSPE) and concordance correlation coefficient (CCC) analysis. The strongest validated stepwise regression models were constructed for milk protein percentage (r = 0.04) and lactation persistency (r = 0.09). To determine if another type of regression analysis would better predict lactation performance, partial least squares (PLS) regression analysis was then applied. Selection of gene expression data was based on an assessment of the linear dependence of all genes in normalized datasets for 81 subjects against 18 dairy herd index (DHI) variables using Pearson correlation analysis. Results were distributed into two lists based on correlation coefficient. Each gene expression dataset was used to construct PLS models for the purpose of predicting lactation performance. The strongest predictive models were generated for protein percentage (r = 0.46), 305-d milk yield (r = 0.44), and 305-d protein yield (r = 0.47). These results demonstrate the suitability of using hepatic gene expression in young animals to quantitatively predict future lactation performance. / Ontario Centre for Agricultural Genomics, NSERC Canada, and the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Intrauterine growth restriction (IUGR) reduces bone mass by 10-30% and impairs arachidonic (AA) and docosahexaenoic (DHA) acid status in infants. Because AA and DHA enhance neonatal bone mass, the aim of this study was to determine the effects of dietary 0.5% AA and 0.2% DHA (w/w) prior to weaning on bone and growth. 40 guinea pigs were randomized to either a control (C) or low-protein diet (LP) during pregnancy and the C diet or the C diet with AA+DHA during lactation. Measurements included bone mass, metabolism, and strength, and erythrocyte lipid of sows and offspring from birth to 16 wk post-partum. The LP diet induced IUGR, while the AA+DHA increased bone mass by 5-20% in sows and offspring and corrected growth and bone mass in IUGR pups. Thus, AA+DHA provided in lactation rescues the growth trajectory in an IUGR state and is beneficial to maternal and neonatal bone mass.

Background: Breastfeeding is known to have benefits both for maternal and child health. Some questions around the benefits and risks of breastfeeding in the presence of HIV infection still remain unclear. Aims: To study the effects of infant feeding mode by HIV-positive mothers, on maternal and child health. In addition, to assess the effect of nutritional supplementation to HIV-positive lactating mothers on nutritional and health status of mothers and their infants and on the quality of breastmilk. Methods: The study had 2 components; a prospective study to examine the impact of infant feeding mode on nutritional and health indices in mothers and their infants and within it a nested randomized controlled clinical trial to study the impact of a daily 50 g soya/peanut based supplement during breastfeeding on the above parameters. The measurements included anthropometry; body composition indicators (using both deuterium dilution and BIA); haematology and biochemical markers; as well as incidence rates of opportunistic infections and clinical disease progression. Breastmilk was analysed for both macro and micronutrients. Cervical screening was offered to all the women. Results: AFASS criteria were fulfilled by 38.7% of the formula feeding mothers. No significant differences between the formula feeding and breastfeeding groups in terms of haematological, immunological and body composition changes were seen. Breastfeeding mothers had significantly lower events with high depression scores (p=0.043). Longer duration of breastfeeding was observed to be significantly associated with a mean increase in CD4 count (74 cells/μL) and better health outcomes. The supplement made no significant impact on any maternal or child outcomes except for a limited effect on mothers with low BMI, where it was significantly associated with preventing loss of lean body mass (p=0.026). Breastfeeding infants had a significantly lower risk of diarrhoea and hospitalisation at 3 months (p=0.006 and 0.014 respectively). Both breastfeeding and longer duration of breastfeeding was significantly associated with better development scores and growth parameters. Supplementation made no impact on breastmilk composition. Of the 86 mothers who agreed for cervical screening, 27.6% had human papilloma virus infection. Conclusions: Breastfeeding is not harmful to the mother despite the presence of HIV infection. On the contrary we observed both breastfeeding and longer breastfeeding duration to be associated with better maternal and child outcomes. Mothers are still choosing formula feeding inappropriately presumably because of the availability of free formula and/or sub-optimal counseling. The new (2010) local PMTCT guidelines based on WHO recommendations should reverse this. Food insecurity was prevalent amongst 32% of our study population, highlighting the need to include sustainable and empowering solutions to encounter this problem. Less sustainable solutions such as nutritional supplementation should be targeted to the malnourished and in emergency situations. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2012.