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Realistic characterization of subglacial hydrology necessitates knowledge of the range in form, scale, and spatiotemporal evolution of drainage networks. A relict subglacial meltwater corridor on the deglaciated Antarctic continental shelf encompasses 80 convergent and divergent channels, many of which are hundreds of meters wide and several of which lack a definable headwater source. Without significant surface‐melt contributions to the bed like similarly described landforms in the Northern Hemisphere, channelized drainage capacity varies non‐systematically by three orders of magnitude downstream. This signifies apparent additions and losses of basal water to the bed‐channelized system that relates to bed topography. Larger magnitude grounding‐line retreat events occurred while the channel system was active than once channelized drainage had ceased. Overall, this corridor demonstrates that meltwater drainage styles co‐exist in time and space in response to bed topography, with prolonged impacts on grounding‐line behavior. Plain Language Summary: Water drainage beneath glacial ice can impact flow of the overlying ice, sediment transport underneath the ice toward the glacier's terminus, and the stability of glacial ice as it transitions from resting on the geologic terrain to floating in the ocean. Despite being an important component of glacial systems, the full range of possible modes of water delivery and how these interact and vary across time and space is not well resolved. We describe a relict subglacial meltwater network preserved on the Antarctic seafloor, representing a persistent pathway for water drainage when the East Antarctic Ice Sheet was much larger. The landforms within the drainage network implicate substantial changes in how subglacial water drainage was influenced by the shape of the underlying terrain and demonstrate the prolonged impacts that meltwater corridors have on the retreat of glacial ice. Key Points: Bed topography was the primary control on the morphology and organization of a large paleo‐subglacial meltwater corridor in AntarcticaThe morphology of the corridor supports downstream gains and losses in meltwater supply and/or changes in drainage styleGrounding‐line retreat events were significantly larger when channels were active and smaller when channelized drainage had ceased [ABSTRACT FROM AUTHOR]

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition thought to be under-diagnosed, with a true prevalence of more than the 1 in 10,000 estimated. It is a condition that is classically described as polyostotic with a relapsing and remitting course, preferentially affecting the metaphyses of tubular bones in the pediatric population. Lesions have characteristic appearances of cortical hyperostosis and mixed lytic/sclerotic medullary appearances radiographically, with active osteitis and periostitis best seen with fluid-sensitive sequences on magnetic resonance imaging (MRI). There are reports of lesions resolving on follow-up radiographs and MRI scans, but no supporting images. In particular, although the marrow appearances and degree of osteitis have been shown to improve on MRI, complete resolution and remodeling back to normal has never been demonstrated. We present a case of a lesion that has completely healed and remodeled back to normal appearances on both radiographs and MRI, and consider this the standard for the often loosely used terms "normalization" and "resolution". We discuss the implications of this for our understanding of the natural history of CRMO, and how this adds weight to the condition being significantly under-diagnosed. It provides a "gold standard" to be aimed for when assessing treatments for CRMO, and the optimal outcomes that are possible. It also provides further insight into the potential of pediatric bone to recover and remodel when affected by inflammatory conditions. [ABSTRACT FROM AUTHOR]

Research was conducted to examine the effects of a diverse pasture mix on dry matter intake, milk yield, and N partitioning of lactating dairy cows. A pasture containing only ryegrass and white clover (RG), or high-sugar ryegrass and white clover (HS), was compared with a diverse pasture mix (HSD) including chicory, plantain, lotus, high-sugar ryegrass, and white clover. The experiment was conducted over a 10-d period using 3 groups of 12 cows in late lactation. No difference was observed in dry matter (14.3 kg of dry matter/ cow per day) or N (583 g of N/cow per day) intake between treatments. The cows grazing the HSD pasture had an increased milk yield (16.9 kg/d) compared with those grazing the simple RG and HS pastures (15.2 and 14.7 kg/d, respectively). However, no differences were observed in milk solids yield for the 3 treatments. A tendency toward greater milk protein yields in the HSD group resulted in improved N use efficiency for milk of 20.4% from the cows fed HSD, compared with 17.8 and 16.7% from cows in the RG and HS treatments, respectively. Urinary N excretion was lower from the cows fed HSD, at 353.8 g/d, compared with 438.3 and 426.6 g/d for cows fed RG and HS, respectively. These results suggest that the use of pastures containing chicory, lotus, and plantain can contribute to the goal of reducing N losses from cows in late lactation. [ABSTRACT FROM AUTHOR]

To determine the zoonotic potential of Cryptosporidium and Giardia in Prince Edward Island (PEI), Canada, 658 human faecal specimens were screened that were submitted to the Queen Elizabeth Hospital diagnostic laboratory. Overall, 143 (22%) samples were Cryptosporidium positive, while three (0.5%) were positive for Giardia. Successful genotyping of 25 Cryptosporidium isolates by sequence analysis of the HSP70 gene revealed that 28 and 72% were C. hominis and C. parvum, respectively. Cryptosporidium isolates from humans and previously genotyped C. parvum from beef cattle were subtyped by sequence analysis of the GP60 gene. Subtyping identified three subtypes belonging to the family IIa. All three subtypes IIaA16G2RI (55%), IIaA16G3RI (22%) and IIaA15G2RI (22%) were found in the animal isolates, while two of the subtypes found in the animals, IIaA16G2RI (80%) and IIaA15G2RI (20%), were also identified in the human isolates. Cryptosporidium infection in humans peaked in April-June. Molecular epidemiological analysis of the human data showed a C. parvum peak in the spring and a relatively smaller peak for C. hominis in July-September. The majority (57%) of human Cryptosporidium isolates were found in children between 5 and 10 years of age. All three Giardia isolates were identified as G. duodenalis assemblage A. The overall Cryptosporidium prevalence in our human samples was high relative to other studies, but because the samples were submitted to a hospital diagnostic laboratory, the results may not be representative of the general population. Further, the presence of the same zoonotic C. parvum subtypes in cattle and human isolates implies that transmission is largely zoonotic and cattle may be a source of sporadic human infections on PEI. The presence of Giardia in people on PEI is rare, and the assemblage A found in humans might originate from humans, livestock or other domestic or wild animals. [ABSTRACT FROM AUTHOR]

The inclusion of the grape marc into livestock rations provides an opportunity not only to use a waste byproduct resourcefully, but also to induce beneficial metabolic changes in animals. Grape marc contains condensed tannins that could alter N metabolism, which would be beneficial from an environmental perspective. The objective was to determine if dietary grape marc could decrease urinary N excretion from nonlactating dairy cattle. Eighteen multiparous cows were randomly divided into 2 equal groups, receiving either (1) pasture + 2 kg of dry matter (DM)/d energy pellet per cow (control group) or (2) pasture + 2 kg of DM/d energy pellet per cow + 3 kg of DM/d grape marc per cow. Urine, fecal, and blood samples were collected at baseline (d 0) and at d 9. Cows receiving grape marc excreted 22% more N in feces compared with the control group. Cows offered grape marc had lower plasma urea nitrogen concentrations (2.42 and 2.97 ± 0.1 mmol/L from treatment and control cows, respectively), but had no significant difference in urine urea concentration compared with control animals (84.24 and 114.1 ± 17.62 mmol/L from treatment and control cows, respectively). Overall, the potential exists to alter N metabolism in dairy cows using dietary grape marc. The exact mechanisms causing this shift in N metabolism require further investigation. [ABSTRACT FROM AUTHOR]

The Gram-positive bacterium Aerococcus viridans var. homari is a well-documented causative agent of the lethal systemic disease gaffkemia in both the American lobster, Homarus americanus, and the European lobster, Homarus gammarus. Previous phenotypic characterization has been unsuccessful at differentiating avirulent from virulent strains without performing lethal animal infection trials. Recent genetic characterization of A. viridans strains through 16S rRNA sequencing and random amplification of polymorphic DNA fingerprinting has revealed the presence of two subtypes. However, subtype 1 contains both virulent and avirulent strains which are genetically identical. The purpose of this study was to determine the proteomic mediators of virulence in A. viridans. Quantitative proteomic mapping of these two strains has revealed 29 differentially expressed protein spots, seven of which are only expressed in the virulent strain and could act as virulence factors. One protein, chaperonin 60 (Cpn60), is uniquely expressed in the virulent strain and has been shown to act as a virulence factor in many other bacteria. The proteomic mapping strategy employed in this study is the first to show phenotypic differences between virulent and avirulent strains. Cpn60 expression represents a potentially useful tool for identifying the virulent strains of A. viridans in epidemiological studies. [ABSTRACT FROM AUTHOR]

Abstract: Using a randomized controlled trial design, a randomly allocated intervention group of 15 cows received a slow-release bolus that delivered 100 days of monensin. The negative control group of 15 cows received a placebo bolus that was identical to the monensin bolus, except without the monensin. Two weeks after bolus administration, all cows were challenged with a 2ml subcutaneous injection of a live tachyzoite suspension. Whole blood and serum samples were collected from each cow every week for the first month post-challenge, and then every 2 weeks for the next 2 months. The extracted DNA from whole blood was tested for the Nc-5 gene fragment of Neospora caninum using a quantitative real time polymerase chain reaction. Serum was tested for antibodies to N. caninum using the IDEXX ELISA. Cows treated with monensin boluses had a significantly lower humoral immune response than cows treated with placebo boluses at one time point post-challenge (week 4 post-challenge). However, when adjusting for repeated measures within cows, the P value for this humoral difference was 0.098. No DNA for N. caninum was detected in either group, likely due to study design features. [ABSTRACT FROM AUTHOR]

Provision of AA has shown success in attenuating proteolytic activity in monogastrics suffering from metabolic acidosis. However, it is unknown whether AA supplementation can provide any beneficial effects to ruminants with nutritionally induced metabolic acidosis. The objective of the current study was to examine the effects of glutamine infusion on various protein degradation components across several tissues in sheep with induced metabolic acidosis. Sheep were assigned to a randomized complete block design with 2 × 2 factorial arrangement of treatments (n = 6 sheep/treatment) consisting of a control or acidosis diet, and receiving a saline or L-glutamine infusion. Sheep were fed diets for 10 d and slaughtered on d 11. Liver, kidney, and muscle samples were collected at slaughter and examined for relative messenger RNA (mRNA) expression of ubiquitin, C8, E2, cathepsin L, cathepsin B, caspase-3, and m-calpain, as well as protein expression of ubiquitin. Relative mRNA expression of C8 (P = 0.02), E2 (P = 0.06), and ubiquitin (P = 0.07) was less in kidney in acidotic vs. control sheep. Additionally, mRNA expression of m-calpain in kidney was greater (P = 0.01) as a result of glutamine infusion. There were no significant alterations (P > 0.10) in mRNA of any component as a result of acidosis in the liver or muscle. This study demonstrates the inability of metabolic acidosis to increase expression of the ubiquitin-mediated proteolytic pathway in skeletal muscle; however, downregulation of renal mRNA expression of these components is apparent during the induction of metabolic acidosis. [ABSTRACT FROM AUTHOR]

This study characterized the effects of nutritionally induced metabolic acidosis with or without Gin infusion on acid-base balance, plasma AA, and plasma NEFA in sheep. In a randomized complete biock design with a 2 x 2 factorial arrangement of treatments, 24 fully fleeced sheep (Rideau-Arcott, 63.6 ± 5.9 kg of BW) were fed a control supplement (CS; 300 g/d of canola meal) or an acidosis supplement (AS; 300 g/d of NutriChior; HCl-treated canoia meal), offered twice daily at 0700 and 1100 h. Sheep were infused at 1400 h daily with 0.3 g of L-glutamine per kg of BW or saline via jugular vein catheters for 7 d. The sheep were individually housed and limit-fed a basal diet of dehydrated alfalfa pellets (1.75 kg/d; 90% DM, 22% CP, and 1.2 Mcal of NEg/kg on a DM basis) offered twice daily at 1000 and 1300 h. Blood and urine was sampled daily between 1100 and 1130 h, and blood samples were analyzed for hematocrit, plasma pH, gases, strong ions, AA, and NEFA, whereas urine was analyzed for pH. The AS reduced (P < 0.01) DM1, urine and plasma pH, blood urea, partial pressure of CO2, strong ion difference, and plasma HCO3-, and increased (P < 0.01) plasma K+, Ca2+ and Cl-. The AS with saline infusion increased (P ≤ 0.03) partial pressure of O2 and plasma glucose, whereas AS with Gin infusion reduced (P < 0.01) partial pressure of O2 and plasma glucose. The AS increased (P < 0.01.) plasma lysine and reduced (P < 0.01) plasma taurine. Glutamine infusion increased (P = 0.04) plasma leucine with the CS treatment but had no effect (P 0.89) with the AS treatment. Plasma 16:0, 18:2n-6, 18:3n-3, 20:4n-6, and total NEFA were increased and 18:0 was decreased (P < 0.001) in AS sheep compared with CS sheep. Infusion of Gin decreased (P < 0.05) 16:0, 18:2n-6, 18:3n-3, 20:4n-6, and total NEFA compared with saline infusion. Plasma cis-9, trans-11 CLA was elevated (P = 0.001) in AS sheep, whereas plasma cis-9, trans-11 CLA, regardless of the diets, was decreased (P < 0.02) with Gln infusion. These results show that despite some improvement in overall mobilization of NEFA, Gin infusion did not ameliorate the negative responses associated with metabolic acidosis. [ABSTRACT FROM AUTHOR]

Metabolic acidosis is a condition often induced by ruminal acidosis. Identification of the specific proteolytic pathways affected by metabolic acidosis and characterization of AA concentration changes induced by metabolic acidosis in ruminants has yet to be confirmed. The objective of this study was to examine the effect of nutritionally induced metabolic acidosis on lamb plasma AA and tissue variables, including mRNA and protein expression of components of the ubiquitin-mediated proteolytic pathway. Lambs (n = 10) were divided evenly into treatment groups receiving alfalfa pellets supplemented with 1) a control canola meal supplement, or 2) HCl-treated canola meal supplement for a 10-d treatment period. On d 11, lambs were slaughtered and liver, muscle, and kidney samples were collected to determine mRNA expression of components of the ubiquitin-mediated proteolytic pathway and ubiquitin protein expression. Plasma concentrations of serine (P = 0.06), glycine (P = 0.002), and glutamine (P = 0.04) were greater in acidotic lambs compared with control animals, indicating that protein catabolism may be occurring. However, no alteration (P > 0.1) in messenger RNA expression of the proteasome subunit C8, ubiquitin-conjugating enzyme E2, or ubiquitin or in ubiquitin protein expression were observed. These results suggest that ubiquitin-mediated proteolysis is not the primary pathway of protein degradation in lambs afflicted with metabolic acidosis. [ABSTRACT FROM AUTHOR]

Abstract: We consider the following problem: given a set X and a function , does there exist a compact Hausdorff topology on X which makes T continuous? We characterize such functions in terms of their orbit structure. Given the generality of the problem, the characterization turns out to be surprisingly simple and elegant. Amongst other results, we also characterize homeomorphisms on compact metric spaces. [Copyright &y& Elsevier]

The article presents a scientific research on purinergic receptors in the human placenta particulalrly on the evidence for functionally active P2X4, P2X7, P2Y2 and P2Y6. Study results lead to the conclusion that the activation of the receptors and a subsequent calcium increase regulates syncytiotrophoblast homeostasis and maternafetal ion exchange as a response to extracellular nucleotides.

In January this year Sally Greenwood travelled to north eastern Sri Lanka to help those affected by the Tsunami. [ABSTRACT FROM AUTHOR]

Three grazing experiments were carried out in late spring (early lactation), summer (mid-lactation) and autumn (late lactation) to compare the effects of perennial ryegrass cultivar or grass species, sown in binary or multispecies mixtures, on milk yield and nitrogen excretion of dairy cows. Replicated groups of multiparous Holstein Friesian × Jersey cows were offered either a control or high-sugar perennial ryegrass ( Lolium perenne) or tall fescue ( Festuca arundinacea) base grass in a binary mixture with white clover ( Trifolium repens) or in a multispecies mixture with additional legumes, bromegrass ( Bromus willdenowii) and forbs. During each 9-day experiment, botanical composition, milk production and faecal and urine composition were measured. Milk solid ( MS) yield for the control ryegrass, high-sugar ryegrass and tall fescue grass types averaged, respectively, 1.53, 1.64 and 1.70 kg MS cow−1 day−1 for a binary mixture sward, compared with 1.65, 1.54 and 1.53 kg MS cow−1 day−1 for a multispecies sward. Legume content influenced milk production more than the number of species present in a mixture. There was lower urine N concentration from a multispecies sward compared with a binary mixture. Urine N concentration of cows grazing the control ryegrass, high-sugar ryegrass and tall fescue grass types averaged, respectively, 4.6, 5.3 and 6.8 g N L−1 for a binary mixture, compared with 4.1, 3.9 and 3.9 g N L−1 for a multispecies mixture. Feeding dairy cows on multispecies swards containing forbs presents an opportunity to reduce N losses without compromising milk yield. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the effect of the timing of feeding maize silage before a short herbage meal on dry matter (DM) intake, milk production, nitrogen (N) partitioning and rumen function of lactating dairy cows. Ten lactating, pregnant, Friesian × Jersey rumen-fistulated dairy cows aged 4-5 years were blocked in pairs by milksolids (MS; sum of protein and fat) production (1.73 ± 0.097 kg MS/cow.day; mean ± s.d.), bodyweight (519 ± 24.7 kg), days in milk (163 ± 12.5), and body condition score (3.9 ± 0.21). Cows within pairs were randomly allocated to one of two treatments: (1) five cows were offered one-third of their estimated total DM intake (5 kg/cow.day) as maize silage after the afternoon milking at 1500 hours, ∼1 h before herbage was provided (1BH); (2) five cows were offered one-third of their estimated total DM intake as maize silage after morning milking at 0700 hours, ∼9 h before herbage was provided (9BH). All cows were offered two-thirds of their total estimatedDMintake (11 kg/cow.day) over a period of 4 h from 1600 hours to 2000 hours as freshly cut perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens) in an indoor system. Cows were adapted to diets for 9 days (Days 1-9), followed by 5 days of measurement (Days 10-14). Maize silage DM intake did not differ between treatments averaging 5.1 kg DM/cow.day. HerbageDMintake was greater (P = 0.02) for 9BH (11.2 kg DM/cow.day) than 1BH (10.4 kg DM/cow.day). Milk yield (P = 0.001) and MS production (P = 0.08) were greater for 9BH than 1BH (18.8 vs 15.4 kg/cow.day and 1.63 vs 1.48 kg MS/cow.day, respectively). There was no effect of time of supplementation on N partitioned to milk, faeces, or urine. The purine derivatives to creatinine ratio, as an indication of microbial protein production, was greater (P = 0.04) for 9BH than 1BH. Daily mean rumen pH and the concentration of total rumen volatile fatty acids, acetate, butyrate, and ammoniaNwere not affected by treatment. However, the peak concentration of ruminal ammoniaNwas 27% lower (P < 0.05) for 9BHthan 1BH. The concentration of non-esterified fatty acid (P = 0.03) and beta-hydroxy butyric acid (P = 0.01) were greater for 1BH than 9BH (0.14 vs 0.09 and 0.81 vs 0.71 mmol/L, respectively). These results indicate that under herbage feed restriction, altering the time of supplementation relative to the herbage meal can increase herbage DM intake and subsequent milk production. [ABSTRACT FROM AUTHOR]

The discovery of the novel orexigenic peptide ghrelin in monogastrics has stimulated research regarding ghrelin's involvement in feed intake in ruminants. Though ghrelin mRNA expression is primarily found in the stomach, mRNA expression has also been observed in various other non-digestive tissues in monogastrics. The objectives of this study were to examine ghrelin mRNA expression in calf tissues, including various non-gastrointestinal tissues, and determine the influence of adrenocorticotrophin hormone (ACTH) injection on ghrelin, leptin and stearoyl-CoA desaturase (SCD) mRNA expression. Twenty-one different tissue types were collected from 6-month-old male Holstein calves (n=12) after euthanasia. The calves were used in a stress response study and were injected with either saline or ACTH. The calves (3/group) were then euthanized at 15, 50 or 100 minutes following injection of 0.56 IU/kg ACTH or immediately following saline injection. RNA was isolated using the TRIzol method, and mRNA expression was determined using Real-time PCR. Cyclophilin was used as the control gene. Ghrelin, leptin and SCD mRNA expression was determined relative to cyclophilin expression and averaged within treatment groups. Ghrelin mRNA expression was most abundant in the abomasum in all treatment groups. However, ghrelin mRNA expression was also observed in the lung, spleen, kidney, aorta, endocardium, testis, epididymis, gall bladder, duodenum, jejunum and ileum. These findings are the first to indicate that ghrelin mRNA expression is present in non-gastrointestinal tissues in ruminants and could provide insight into possible endocrine and/or paracrine roles of ghrelin. [ABSTRACT FROM AUTHOR]

Four cohorts of nonlactating, pregnant dairy cows (n = 50, 47, 45, and 42) were individually fed indoors to determine the amount of feed required for body weight (BW) gain from autumn pasture and commonly used supplementary feeds. These results were used to estimate the apparent efficiency with which metabolizable energy (ME) is used for BW gain (app_kg). Control cows were offered autumn pasture to estimated maintenance requirements (~0.55 MJ of ME/kg of BW0.75), with an additional 20 MJ of ME/d allocated for pregnancy and activity. All other cows received the same allowance of autumn pasture and an additional allowance (2.5 or 5.0 kg of dry matter/d) of autumn pasture (Past), spring pasture silage (Psil), maize silage (Msil), cracked maize grain (Mgr), or palm kernel expeller (PKE), resulting in a total of 11 treatments. Individual cow dry matter intake was determined daily; BW was recorded once per week for cohorts 1 and 2, and 3 times per week for cohorts 3 and 4. The ME contents of feeds were estimated from feed quality assays. Regression analyses were used on each feed to determine the ME requirement for 1 kg of BW gain. The app_kg of Past and Msil was 0.34 and 0.47, respectively; these estimates are in line with published literature. The app_kg of Psil (0.50) was consistent with the published kg for spring pasture, from which the silage was made. Palm kernel expeller had the greatest app_kg (0.61). The reasons for this cannot be deduced from the current study but may reflect the relatively high fat content of the feed and the high kg of fat. The app_kg for Mgr was low (0.38) in comparison with the other supplementary feeds and, in particular, relative to its feed ME and published kg estimates. Although the reason for the low app_kg cannot be deduced from the current data, the most plausible reason is the preferential use of propionate-derived glucose for conceptus metabolism rather than BW gain, a factor not accounted for in previous experimental models that did not use late-gestation cows. In summary, the app_kg for autumn pasture was low but consistent with historical growth rate trials in other ruminant species. In comparison, Msil, Psil, and PKE were used with a greater apparent efficiency (app_kg = 0.47 to 0.61), but Mgr resulted in a relatively low rate of gain per MJ of ME (app_kg = 0.38). These differences have implications for accurate feed budgeting on farm. [ABSTRACT FROM AUTHOR]

Gene expression profiling of bovine rumen tissue has provided insight into dietary regulation of rumen epithelial function. However, most studies have relied on a heterogeneous sample with multiple tissue and cell types. The objective of this study was to use laser capture microdissection to characterize RNA expression profiling of epithelial and connective tissues of rumen papillae. Papillae were biopsied from 3 lactating dairy cows, frozen in cryomolds, cut into sections, stained, and dehydrated, and epithelial and connective cells were collected using laser capture microdissection. Total RNA was isolated from epithelial and connective tissue and global gene expression was assessed using the Affymetrix GeneChip Bovine Gene 1.0 ST array (Affymetrix, Santa Clara, CA). Data preprocessing was conducted using the robust multi-array average method, and detection of differentially expressed genes (DEG) was determined using ANOVA. The model included the fixed effect of tissue, and a Benjamini-Hochberg false discovery rate of 0.1 was applied to DEG. We found 382 DEG between epithelial and connective tissues. Analysis of these DEG using Ingenuity Pathway Analysis (Redwood City, CA) found that epithelial and connective tissues in rumen papillae expressed distinct RNA profiles (signatures). The epithelial signature was enriched with RNA encoding tight junction and metabolic genes, whereas connective signatures were enriched with RNA encoding proteins involved in cell structure and extracellular matrix composition. The molecular functions enriched within the top networks between the 2 tissues from the Ingenuity Pathway Analysis included connective tissue disorders, dermatological diseases and conditions, gastrointestinal disease, tissue morphology, and tissue development. In summary, it is possible to use laser capture microdissection for the localization of tissue-specific global gene expression in rumen papillae. This approach may be useful to improve the accuracy and interpretation of molecular measurements in future studies. [ABSTRACT FROM AUTHOR]

Fifty-three nonlactating, pregnant Holstein-Friesian and Holstein-Friesian x Jersey cross dairy cows were grouped into 4 cohorts (n = 15, 12, 13, and 13) and offered 1 of 3 allowances of fresh, cut pasture indoors for 38 ± 2 d (mean ± SD). Cows were released onto a bare paddock after their meal until the following morning. Animals were blocked by age (6 ± 2 yr), day of gestation (208 ± 17 d), and body weight (BW; 526 ± 55 kg). The 3 pasture allowances [low: 7.5 kg of dry matter (DM), medium: 10.1 kg of DM, or high: 12.4 kg of DM/cow per day] were offered in individual stalls to determine the estimated DM and metabolizable energy (ME) intake required for zero energy balance. Individual cow DM intake was determined daily and body condition score was assessed once per week. Cow BW was recorded once per week in cohorts 1 and 2, and 3 times per week in cohorts 3 and 4. Low, medium, and high allowance treatments consumed 7.5, 9.4, and 10.6 kg of DM/cow per day [standard error of the difference (SED) = 0.26 kg of DM], and BW gain, including the conceptus, was 0.2, 0.6, and 0.9 kg/cow per day (SED = 0.12 kg), respectively. The ME content of the pasture was estimated from in vitro true digestibility and by near infrared spectroscopy. Total ME requirements for maintenance, pregnancy, and limited activity were 1.07 MJ of ME/kg of measured metabolic BW per day. This is more than 45% greater than current recommendations. Differences may be due to an underestimation of ME requirements for maintenance or pregnancy, an overestimation of diet metabolizability, or a combination of these. Further research is necessary to determine the reasons for the greater ME requirements measured in the present study, but the results are important for on-farm decisions regarding feed allocation for nonlactating, pregnant dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of dietary fiber level on milk fat concentration, yield, and fatty acid (FA) profile of cows fed diets low in polyunsaturated fatty acid (PUFA). Six rumenfistulated Holstein dairy cows (639 ± 51 kg of body weight) were used in the study. Cows were randomly assigned to 1 of 2 dietary treatments, a high fiber (HF; % of dry matter, 40% corn silage, 27% alfalfa silage, 7% alfalfa hay, 18% protein supplement, 4% ground corn, and 4% wheat bran) or a low fiber (LF; % of dry matter, 31% corn silage, 20% alfalfa silage, 5% alfalfa hay, 15% protein supplement, 19% ground wheat, and 10% ground barley) total mixed ration. The diets contained similar levels of PUFA. The experiment was conducted over a period of 4 wk. Ruminal pH was continuously recorded and milk samples were collected 3 times a week. Milk yield and dry matter intake were recorded daily. The rumen fluid in cows receiving the LF diet was below pH 5.6 for a longer duration than in cows receiving the HF diet (357 vs. 103 min/d). Neither diet nor diet by week interaction had an effect on milk yield (kg/d), milk fat concentration and yield, or milk protein concentration and yield. During wk 4, milk fat concentration and milk fat yield were high and not different between treatments (4.30% and 1.36 kg/d for the HF treatment and 4.31% and 1.33 kg/d for the LF treatment, respectively). Cows receiving the LF diet had greater milk concentrations (g/100 g of FA) of 7:0; 9:0; 10:0; 11:0; 12:0; 12:1; 13:0; 15:0; linoleic acid; FA

Blood flow control within the fetoplacental circulation is poorly understood despite the essential role of the placenta in pregnancy. Our study compared an in vitro assessment of placental chorionic plate small artery function with in vivo measures of umbilical artery blood flow. Umbilical artery Doppler waveform analysis was performed on women (N=8) with uncomplicated pregnancies within 24 hours of delivery. Small arteries (n=25) were dissected from the placental chorionic plate from biopsies at term and studied using parallel wire myography. Chorionic plate arteries developed maintained constrictions to the thromboxane-mimetic U46619. Nitric oxide (NO) donation with the endothelial-independent agent sodium nitroprusside elicited significant relaxation compared to paired control vessels. This vasodilatation correlated significantly with both pulsatility and resistance indices measured in the umbilical artery. We conclude that Doppler indices in the umbilical artery are inversely proportional to the maximal relaxation achieved by chorionic plate small arteries in response to a NO donor. [ABSTRACT FROM AUTHOR]

Tests the hypothesis that adenosine triphosphate (ATP) stimulates a potassium[sup+] (K[sup+]) efflux pathway in cytotrophoblast cells via elevation of calcium&sup2+; (Ca&sup2+;). Characterization of the K[sup+] channel underlying the [sup86]rubidium efflux pathway in cytotrophoblast cells; Physiological role of 1K in the human placenta; Factors representing the change in size of the ATP response during cytotrophoblast differentiation.

Fetal growth restriction (FGR), where a fetus fails to reach its genetic growth potential, affects up to 8% of pregnancies and is a major risk factor for stillbirth and adulthood morbidity. There are currently no treatments for FGR, but candidate therapies include the phosphodiesterase-5 inhibitor sildenafil citrate (SC). Randomized clinical trials in women demonstrated no effect of SC on fetal growth in cases of severe early onset FGR; however, long-term health outcomes on the offspring are unknown. This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure, and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg/kg) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in wild-type (WT) female offspring (P < 0.05) and reduced glucose sensitivity in both WT (P < 0.01) and P0 (P < 0.05) female offspring compared with controls. Antenatal SC treatment increased systolic blood pressure in both male (WT vs. WT-SC: 117 ± 2 vs. 140 ± 3 mmHg, P < 0.0001; P0 vs. P0-SC: 113 ± 3 vs. 140 ± 4 mmHg, P < 0.0001; means ± SE) and female (WT vs. WT-SC: 121 ± 2 vs. 140 ± 2 mmHg, P < 0.0001; P0 vs. P0-SC: 117 ± 2 vs. 144 ± 4 mmHg, P < 0.0001) offspring at 8 and 13 wk of age. Increased systolic blood pressure was not attributed to altered mesenteric artery function. In utero exposure to SC may result in metabolic dysfunction and elevated blood pressure in later life. [ABSTRACT FROM AUTHOR]

Fetal growth restriction (FGR), where a fetus fails to reach its genetic growth potential, affects up to 8% of pregnancies and is a major risk factor for stillbirth and adulthood morbidity. There are currently no treatments for FGR, but candidate therapies include the phosphodiesterase-5 inhibitor sildenafil citrate (SC). Randomized clinical trials in women demonstrated no effect of SC on fetal growth in cases of severe early onset FGR; however, long-term health outcomes on the offspring are unknown. This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure, and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg/kg) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in wild-type (WT) female offspring (P < 0.05) and reduced glucose sensitivity in both WT (P < 0.01) and P0 (P < 0.05) female offspring compared with controls. Antenatal SC treatment increased systolic blood pressure in both male (WT vs. WT-SC: 117 ± 2 vs. 140 ± 3 mmHg, P < 0.0001; P0 vs. P0-SC: 113 ± 3 vs. 140 ± 4 mmHg, P < 0.0001; means ± SE) and female (WT vs. WT-SC: 121 ± 2 vs. 140 ± 2 mmHg, P < 0.0001; P0 vs. P0-SC: 117 ± 2 vs. 144 ± 4 mmHg, P < 0.0001) offspring at 8 and 13 wk of age. Increased systolic blood pressure was not attributed to altered mesenteric artery function. In utero exposure to SC may result in metabolic dysfunction and elevated blood pressure in later life. NEW & NOTEWORTHY Sildenafil citrate (SC) is currently used to treat fetal growth restriction (FGR). We demonstrate that SC is ineffective at treating FGR, and leads to a substantial increase systolic blood pressure and alterations in glucose homeostasis in offspring. We therefore urge caution and suggest that further studies are required to assess the safety and efficacy of SC in utero, in addition to the implications on long-term health. [ABSTRACT FROM AUTHOR]

Fetal growth restriction (FGR), where a fetus fails to reach its genetic growth potential, affects up to 8% of pregnancies and is a major risk factor for stillbirth and adulthood morbidity. There are currently no treatments for FGR, but candidate therapies include the phosphodiesterase-5 inhibitor sildenafil citrate (SC). Randomized clinical trials in women demonstrated no effect of SC on fetal growth in cases of severe early onset FGR; however, long-term health outcomes on the offspring are unknown. This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure, and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg/kg) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in wild-type (WT) female offspring (P < 0.05) and reduced glucose sensitivity in both WT (P < 0.01) and P0 (P < 0.05) female offspring compared with controls. Antenatal SC treatment increased systolic blood pressure in both male (WT vs. WT-SC: 117 ± 2 vs. 140 ± 3 mmHg, P < 0.0001; P0 vs. P0-SC: 113 ± 3 vs. 140 ± 4 mmHg, P < 0.0001; means ± SE) and female (WT vs. WT-SC: 121 ± 2 vs. 140 ± 2 mmHg, P < 0.0001; P0 vs. P0-SC: 117 ± 2 vs. 144 ± 4 mmHg, P < 0.0001) offspring at 8 and 13 wk of age. Increased systolic blood pressure was not attributed to altered mesenteric artery function. In utero exposure to SC may result in metabolic dysfunction and elevated blood pressure in later life. [ABSTRACT FROM AUTHOR]

Canadian oil and gas company, Reconnaissance Energy Africa (ReconAfrica), plans to exploit potential oil reserves in the Cubango Okavango River Basin (CORB) in Namibia and Botswana, where little is known about the local groundwater systems and how contamination and its effects could impact the region. Using borehole data from target oil and gas areas, we calculated hydraulic gradients, flow direction, and flow velocity to map potential groundwater contamination effects from oil and gas drilling in the region. We also plotted the major geological structures, calculated flowpaths, and estimated travel times for contaminated groundwater that may travel along these preferential flowpaths from the drill sites to the Okavango River and Delta. Results indicate that contaminated groundwater from the oil lease areas could take 3–23.5 years to reach the Okavango River system via the shallow sandy aquifer, but in a worst-case scenario, contamination could reach the Delta within four days via structures associated with dykes and faults that serve as primary flowpaths. Such contamination could adversely affect human health and the region's ecosystems and biodiversity. We recommend prohibiting oil exploration and production activities within the CORB until future studies can determine the impacts of hydrocarbon extraction with greater certainty. • Oil is currently being explored for in the Okavango region. • Oil drilling contaminants could pollute the groundwater in the drilling area. • Current drilling site contamination could reach the Okavango River within 10 years. • Groundwater contamination could have lasting effects on ecosystems and communities. [ABSTRACT FROM AUTHOR]

Heat treatment of colostrum is performed on modern dairy farms to reduce pathogenic contamination before hand-feeding the colostrum to newborn calves; however, limited data are available concerning effects of heat treatment on biologically active proteins in colostrum. The objective of this exploratory study was to investigate effects of heat treatment and length of heat treatment on colostrum protein profile. Colostrum samples were collected from Holstein cows within 12 h after parturition and assigned to the following groups: heat treatment at 60°C for 0 (untreated control), 30, 60, or 90 min. Samples were fractionated using acid precipitation, followed by ultracentrifugation and ProteoMiner (Bio-Rad Laboratories, Hercules, CA) treatment, and tandem-mass tagging was used to comparatively assess the low abundance protein profile. A total of 162 proteins were identified with more than 2 peptides in the low abundance protein enriched fraction. Of these, 62 differed in abundance by more than 2-fold in heat-treated samples compared with the unheated control. The majority of proteins affected by heat treatment were involved in immunity, enzyme function, and transport-related processes; affected proteins included lactadherin, chitinase-3-like protein 1, and complement component C9. These results provide a foundation for further research to determine optimum heat treatment practices to ensure newborn calves are fed colostrum-containing proteins with the highest nutritional and biological value. [ABSTRACT FROM AUTHOR]

Little is known about the bovine milk proteome or whether it can be affected by diet. The objective of this study was to determine if the dietary rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio could alter the bovine milk proteome. Six Holstein cows (parity: 2.5 ± 0.8) in mid lactation were blocked by days in milk (80 ± 43 d in milk) and milk yield (57.5 ± 6.0 kg) and randomly assigned to treatment groups. The experiment was conducted as a double-crossover design consisting of three 21-d periods. Within each period, treatment groups received diets with either (1) a high RDP:RUP ratio (RDP treatment: 62.4:37.6% of crude protein) or (2) a low RDP:RUP ratio (RUP treatment: 51.3:48.7% of crude protein). Both diets were isonitrogenous and isoenergetic (crude protein: 18.5%, net energy for lactation: 1.8 Mcal/kg of dry matter). To confirm N and energy status of cows, dry matter intake was determined daily, rumen fluid samples were collected for volatile fatty acid analysis, blood samples were collected for plasma glucose, β-hydroxybutyrate, urea nitrogen, and fatty acid analysis, and total 24-h urine and fecal samples were collected for N analysis. Milk samples were collected to determine the general milk composition and the protein profile. Milk samples collected for high-abundance protein analysis were subjected to HPLC analysis to determine the content of α-casein, β-casein, and κ-casein, as well as α-lactalbumin and β-lactoglobulin. Samples collected for low-abundance protein analysis were fractionated, enriched using ProteoMiner treatment, and separated using sodium dodecyl sulfate-PAGE. After excision and digestion, the peptides were analyzed using liquid chromatography (LC) tandem mass spectrometry (MS/MS). The LC-MS/MS data were analyzed using PROC GLIMMIX of SAS (version 9.4, SAS Institute Inc., Cary, NC) and adjusted using the MULTTEST procedure. All other parameters were analyzed using PROC MIXED of SAS. No treatment differences were observed in dry matter intake, milk yield, general milk composition, plasma parameters, or rumen volatile fatty acid concentrations, indicating no shift in total energy or protein available. Milk urea N and plasma urea N concentrations were higher in the RDP group, indicating some shift in N partitioning due to diet. A total of 595 milk proteins were identified, with 83% of these proteins known to be involved in cellular processes. Although none of the low-abundance proteins identified by LC-MS/MS were affected by diet, feeding a diet high in RUP decreased β-casein, κ-casein, and total milk casein concentration. Further investigations of the interactions between diet and the milk protein profile are needed to manipulate the milk proteome using diet. [ABSTRACT FROM AUTHOR]

Background/Objectives:Maternal obesity increases the risk of poor pregnancy outcome including stillbirth, pre-eclampsia, fetal growth restriction and fetal overgrowth. These pregnancy complications are associated with dysfunctional syncytiotrophoblast, the transporting epithelium of the human placenta. Taurine, a β-amino acid with antioxidant and cytoprotective properties, has a role in syncytiotrophoblast development and function and is required for fetal growth and organ development. Taurine is conditionally essential in pregnancy and fetal tissues depend on uptake of taurine from maternal blood. We tested the hypothesis that taurine uptake into placental syncytiotrophoblast by the taurine transporter protein (TauT) is lower in obese women (body mass index (BMI)⩾30 kg m−2) than in women of ideal weight (BMI 18.5-24.9 kg m−2) and explored potential regulatory factors.Subjects/Methods:Placentas were collected from term (37-42-week gestation), uncomplicated, singleton pregnancies from women with BMI 19-49 kg m−2. TauT activity was measured as the Na+-dependent uptake of 3H-taurine into placental villous fragments. TauT expression in membrane-enriched placental samples was investigated by western blot. In vitro studies using placental villous explants examined whether leptin or IL-6, adipokines/cytokines that are elevated in maternal obesity, regulates TauT activity.Results:Placental TauT activity was significantly lower in obese women (BMI⩾30) than women of ideal weight (P<0.03) and inversely related to maternal BMI (19-49 kg m−2; P<0.05; n=61). There was no difference in TauT expression between placentas of ideal weight and obese class III (BMI⩾40) subjects. Long-term exposure (48 h) of placental villous explants to leptin or IL-6 did not affect TauT activity.Conclusions:Placental TauT activity at term is negatively related to maternal BMI. We propose that the reduction in placental TauT activity in maternal obesity could lower syncytiotrophoblast taurine concentration, compromise placental development and function, and reduce the driving force for taurine efflux to the fetus, thereby increasing the risk of poor pregnancy outcome. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine if transcript abundance of genes involved in metabolic pathways in adipose and liver tissue could provide some explanation for the low efficiency with which ME in autumn pasture is used for BW gain. Nonlactating, pregnant (208 ± 19 d of gestation or approximately 75 d precalving) dairy cows (n = 90) were randomly allocated to either a control diet (i.e., offered fresh autumn pasture to maintenance requirements: 0.55 MJ ME/kg of measured metabolic BW [BW0.75] per day) or, in addition to the control diet, 1 of 2 supplement amounts (2.5 and 5.0 kg DM/d) of autumn pasture or 1 of 4 supplementary feeds (i.e., a control and 2 levels of feeding for each of 5 feeds: 11 groups of cows). Along with autumn pasture, evaluated feeds included spring pasture silage, maize silage, maize grain, and palm kernel expeller. Adipose and liver tissues were biopsied in wk 4 of the experiment and transcript abundance of genes involved in metabolic pathways associated with energy metabolism, lipolysis, and lipogenesis was determined. Additional feed, irrespective of type, increased BW gain (P < 0.01) and this effect was reflected in the expression of genes in adipose and liver tissue. However, autumn pasture had lower energy-use efficiency than the other feeds. Genes involved in both lipogenesis (ACACA, THRSP, GPAM, GPD1, and LPL) and lipolysis (PNPLA2) were upregulated (P < 0.05) in adipose tissue in response to increased ME intake/kilogram BW0.75. Hepatic expression of APOA1 decreased and that of APOB increased (P < 0.05) in cows offered maize grain and maize silage (i.e., starch-containing feeds). In comparison, pasture-fed cows demonstrated a degree of uncoupling of the somatotropic axis, with lower hepatic transcript abundance of both GHR1A and IGF-1 compared with cows offered any of the other 4 feeds. Changes to gene transcription indicate a possible molecular mechanism for the poor BW gain evident in ruminants consuming autumn pasture. [ABSTRACT FROM AUTHOR]

Lake Sturgeon ( Acipenser fulvescens Rafinesque, 1917) in Lake Superior are greatly depressed from their historic abundance, and few populations meet the rehabilitation goals identified by management agencies. A netting program targeting juvenile Lake Sturgeon (ages 3-15) was implemented from 2010 to 2012 in Goulais Bay, a shallow, productive bay in the south-eastern part of the lake, to determine abundance, distribution, population characteristics (size structure, condition, age structure, mortality and growth), and recruitment patterns. Five-hundred and thirty-one individuals were captured over the 3-year study, resulting in a mark-recapture estimate of 4977 (95% CIs 3295-7517) juveniles. Catch rates in this study were higher than in any other location in Lake Superior, with sturgeon being broadly distributed around the bay. Estimated annual survival rate ranged from 0.691 to 0.858, depending on the method used. The majority of fish captured were between 620 and 800 mm in total length and were between 4 and 10 years of age (range 1-29 years). Recruiting year-classes were apparent every year, with no apparent effects due to lampricide treatments (a suspected threat to age-0 Lake Sturgeon) in the Goulais River. Year-class strength was positively related to spring water levels. It is possible that this robust Goulais Bay population could help re-populate the south-eastern part of Lake Superior, which contains a number of large, productive embayment areas that formerly supported large Lake Sturgeon populations. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine if the inflammation associated with subclinical endometritis (SCE) is a part of the mechanism by which reproductive performance is reduced in cows with this disease. If it is, reducing inflammation associated with SCE with a nonsteroidal antiinflammatory drug (NSAID) should reduce the severity [as measured by average polymorphonuclear cell (PMN) percentage] of uterine pathology and improve reproductive performance. It was also investigated whether the NSAID treatment reduced metabolic indicators of systemic inflammation previously reported to be altered in cows with SCE. Holstein-Friesian and Friesian-Jersey cross dairy cows (n = 213) were paired by calving date and d-14 uterine PMN percentage and randomly assigned to 3 injections at intervals of 3 d of an NSAID (1.4 mg of carprofen/ kg; n = 104) between 21 and 31 d postpartum or left as untreated controls (n = 109). Cows with ≥14% PMN (upper quartile of PMN percentage) in the cytological sample collected at d 14 postpartum were defined as having SCE. The average d-14 PMN percentage was low (9.9%) and a high self-cure rate of SCE (>90%) at d 42 was observed. Treatment with an NSAID reduced plasma concentrations of aspartate aminotransferase and increased pregnancy rate in SCE cows. However, no effect of the NSAID treatment was observed on PMN percentage at d 42, postpartum anovulatory interval, or milk production. Compared with cows without SCE, cows with SCE had lower plasma albumin concentration, albumin:globulin ratio, and body condition score, but higher nonesterified fatty acids on the day of calving. These results indicate that cows with SCE are experiencing a physiological dysfunction, including lower body condition, liver dysfunction, and greater metabolic challenge during the periparturient period. Further research is required to determine the effect of NSAID on SCE and to evaluate the influence of timing of drug application on treatment effectiveness. [ABSTRACT FROM AUTHOR]

Background and Purpose: Proteinase-activated receptor-2 (PAR2) is widely expressed in the CNS under normal physiological conditions. However, its potential role in modulating neuronal excitability and synaptic transmission remains to be determined. Here, we have investigated whether PAR2 activation modulates synaptic activity in the hippocampus.Experimental Approach: PAR2 activation and its effect on the hippocampus were examined in rat primary cultures and acute slices using whole cell patch clamp and standard extracellular recordings, respectively.Key Results: PAR2 activation leads to a depolarization of hippocampal neurones and a paradoxical reduction in the occurrence of synaptically driven spontaneous action potentials (APs). PAR2-induced neuronal depolarization was abolished following either the inhibition of astrocytic function or antagonism of ionotropic glutamate receptors whilst the PAR2-induced decrease in AP frequency was also reduced when astrocytic function was inhibited. Furthermore, when examined in acute hippocampal slices, PAR2 activation induced a profound long-term depression of synaptic transmission that was dependent on NMDA receptor activation and was sensitive to disruption of astrocytic function.Conclusions and Implications: These novel findings show that PAR2 activation indirectly inhibits hippocampal synaptic activity and indicate that these receptors may play an active role in modulating normal physiological CNS function, in addition to their role in pathophysiological disorders. [ABSTRACT FROM AUTHOR]

Background and Purpose: Cannabidiol (CBD) has emerged as an interesting compound with therapeutic potential in several CNS disorders. However, whether it can modulate synaptic activity in the CNS remains unclear. Here, we have investigated whether CBD modulates synaptic transmission in rat hippocampal cultures and acute slices.Experimental Approach: The effect of CBD on synaptic transmission was examined in rat hippocampal cultures and acute slices using whole cell patch clamp and standard extracellular recordings respectively.Key Results: Cannabidiol decreased synaptic activity in hippocampal cultures in a concentration-dependent and Pertussis toxin-sensitive manner. The effects of CBD in culture were significantly reduced in the presence of the cannabinoid receptor (CB(1) ) inverse agonist, LY320135 but were unaffected by the 5-HT(1A) receptor antagonist, WAY100135. In hippocampal slices, CBD inhibited basal synaptic transmission, an effect that was abolished by the proposed CB(1) receptor antagonist, AM251, in addition to LY320135 and WAY100135.Conclusions and Implications: Cannabidiol reduces synaptic transmission in hippocampal in vitro preparations and we propose a role for both 5-HT(1A) and CB(1) receptors in these CBD-mediated effects. These data offer some mechanistic insights into the effects of CBD and emphasize that further investigations into the actions of CBD in the CNS are required in order to elucidate the full therapeutic potential of CBD. [ABSTRACT FROM AUTHOR]

To determine the effect of metabolic acidosis on expression of L-Gln, b-Gill, and L-Asp metabolizing enzymes and transporters, the relative content of mRNA, protein, or mRNA and protein, of 6 enzymes and 5 transporters was determined by real-time reverse transcription-PCR and immunobiot analyses in homogenates of kidney, skeletal muscle, and liver of growing lambs fed a common diet supplemented with canola meal (control; n = 5) or HC1-treated canola meal (acidosis; n = 5). Acidotic sheep had a 790% greater (P = 0.050) expression of renal Na+-coupled neutral AA transporter 3 mRNA and a decreased expression of renal glutamine synthetase mRNA (47% reduction, P = 0.037) and protein (57% reduction, P = 0.015) than control sheep. No change in renal cytosolic phosphoenolpyruvate carboxykinase (protein and mRNA), glutaminase (mRNA), or L-Glu dehydrogenase (protein) was found. In skeletal muscle, acidotic sheep had 101% more (P = 0.026) aspartate transaminase protein than did control sheep, whereas no change in the content of 3 Na+-coupled neutral AA transporters (mRNA) or 2 high-affinity L-Glu transporter proteins was found. In liver, no change in the content of any assessed enzyme or transporter was found. Collectively, these findings suggest that tissue-level responses of sheep to metabolic acidosis are different than for nonruminants. More specifically, these results indicate the potential capacity for metabolism of L-Asp and L-Glu by skeletal muscle, and L-Gln absorption by kidneys, but no change in hepatic expression of L-Gln metabolism, elaborates previous metabolic studies by revealing molecular-level responses to metabolic acidosis in sheep. The reader is cautioned that the metabolic acidosis model employed in this study differs from the increased plasma lactateinduced metabolic acidosis commonly observed in ruminants fed a highly fermentable grain diet. [ABSTRACT FROM AUTHOR]

Placental system A activity is important for the supply of neutral amino acids needed for fetal growth. There are three system A isoforms: SNAT1, SNAT2 and SNAT4, but the contribution of each to system A-mediated transport is unknown. Here, we have used immunohistochemistry to demonstrate that all three isoforms are present in the syncytiotrophoblast suggesting each plays a role in amino acid transport across the placenta. We next tested the hypothesis that the SNAT4 isoform is functional in microvillous plasma membrane vesicles (MVM) from normal human placenta using a method which exploits the unique property of SNAT4 to transport both cationic amino acids as well as the system A-specific substrate MeAIB. The data show that SNAT4 contribution to system A-specific amino acid transport across MVM is higher in first trimester placenta compared to term (approx. 70% and 33%, respectively, P < 0.01). Further experiments performed under more physiological conditions using intact placental villous fragments suggest a contribution of SNAT4 to system A activity in first trimester placenta but minimal contribution at term. In agreement, Western blotting revealed that SNAT4 protein expression is higher in first trimester MVM compared to term ( P < 0.05). This study provides the first evidence of SNAT4 activity in human placenta and demonstrates the contribution of SNAT4 to system A-mediated transport decreases between first trimester and term: our data lead us to speculate that at later stages of gestation SNAT1 and/or SNAT2 are more important for the supply of amino acids required for normal fetal growth. [ABSTRACT FROM AUTHOR]

Williams JL, Fyfe GK, Sibley CP, Baker PN, Greenwood SL. K[sub+] channel inhibition modulates the biochemical and morphological differentiation of human placental cytotrophoblast cells in vitro. Am J Physiol Regul Integr Comp Physiol 295: R1204-R1213, 2008. First published August 13, 2008; doi: 10.11 52/ajpregu.00l 93.2008.-Maintaining placental syncytiotrophoblast, a specialized multinucleated transport epithelium, is essential for normal human pregnancy. Syncytiotrophoblast continuously renews through differentiation and fusion of cytotrophoblast cells, under paracrine control by syncytiotrophoblast production of human chorionic gonadotropin (hCG). We hypothesized that K[sup+] channels participate in trophoblast syncytialization and hCG secretion in vitro. Two models of normal-term placenta were used: 1) isolated cytotrophoblast cells and 2) villous tissue in explant culture. Cells and explants were treated with K[sup+] channel modulators from 18 h, and day 3, onward, respectively. Culture medium was analyzed for hCG, to assess secretion, as well as for lactate dehydrogenase (LDH), to indicate cellltissue integrity. hCG was also measured in cytotrophoblast cell lysates, indicating cellular production. Syncytialization of cytotrophoblast cells was assessed by immunofluorescent staining of desmosomes and nuclei. Over 18-66 h, mononucleate cells fused to form multinucleated syncytia, accompanied by a 28-fold rise in hCG secretion. 1 mM Ba[sub2+] stimulated cytotrophoblast cell hCG secretion at 66 h compared with control, whereas 5 mM tetraethylammonium (TEA) inhibited hCG secretion by >90%. 0.1-1 mM 4-aminopyridine (4-AP) reduced cytotrophoblast cell hCG secretion and elevated cellular hCG; without altering cellular integrity or syncytialization. In villous explants, hCG secretion was not altered by 1 mM Ba[sub2+] but inhibited by 5 mM 4-AP and 5/10 mM TEA, without affecting LDH release. Anandamide, pinacidil, and cromakalim were without effect in either model. In conclusion, 4-APand TEA-sensitive K[sup+] channels (e.g., voltage-gated and Ca[sub2+]-activated) regulate trophoblast hCG secretion in culture. If these K[sub+] channels participate in hCG secretion in situ, they may regulate trophoblast turnover in health and disease. [ABSTRACT FROM AUTHOR]

The system A amino acid transporter is encoded by three members of the Slc38 gene family, giving rise to three subtypes: Nat-coupled neutral amino acid transporter (SNAT)1, SNAT2, and SNAT4. SNAT2 is expressed ubiquitously in mammalian tissues; SNAT1 is predominantly expressed in heart, brain, and placenta; and SNAT4 is reported to be expressed solely by the liver. In the placenta, system A has an essential role in the supply of neutral amino acids needed for fetal growth. In the present study, we examined expression and localization of SNAT1, SNAT2, and SNAT4 in human placenta during gestation. Real-time quantitative PCR was used to examine steady-state levels of system A subtype mRNA in early (6-10 wk) and late (10-13 wk) first-trimester and full-term (38-40 wk) placentas. We detected mRNA for all three isoforms from early gestation onward. There were no differences in SNAT1 and SNAT2 mRNA expression with gestation. However, SNAT4 mRNA expression was significantly higher early in the first trimester compared with the full-term placenta (P < 0.01). We next investigated SNAT4 protein expression in human placenta. In contrast to the observation for gene expression, Western blot analysis revealed that SNAT4 protein expression was significantly higher at term compared with the first trimester (P < 0.05). Immunohistochemistry and Western blot analysis showed that SNAT4 is localized to the microvillous and basal plasma membranes of the syncytiotrophoblast, suggesting a role for this isoform of system A in amino acid transport across the placenta. This study therefore provides the first evidence of SNAT4 mRNA and protein expression in the human placenta, both at the first trimester and at full term. [ABSTRACT FROM AUTHOR]

Background In fetal growth restriction (FGR) abnormal umbilical artery (UA) Doppler waveform indices suggest increased vascular resistance and impaired placental blood flow. This study aimed to determine whether UA Doppler waveform indices were related to the vasoreactivity of placental chorionic plate small arteries in normal and FGR pregnancies. Materials and methods UA Doppler waveform analysis was performed 24 h before delivery in 23 normal term and 15 FGR pregnancies. Post-delivery responses of chorionic plate arteries to vasoactive agents were examined using the technique of wire myography. Results Altered vascular reactivity to agonists was demonstrated in chorionic plate arteries in FGR pregnancy. Constriction to U46619 (thromboxane mimetic) and relaxation to sodium nitroprusside (nitric oxide donor) were significantly increased in the arteries of FGR pregnancies compared with normal pregnancies. No relationship existed between Doppler indices and chorionic plate responses in normal or FGR pregnancies. Conclusions Fetoplacental vascular reactivity is altered in FGR pregnancy independently of UA Doppler waveform indices. Altered function may be additive to the pathophysiology underlying abnormal Doppler waveforms and could contribute to the inappropriate control of vascular tone in FGR. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare Na+/H+ exchanger (NHE) activity in the microvillous (MVM) and basal (BM) plasma membrane of the human placental syncytiotrophoblast and to determine the relative contribution of various NHE isoforms to this activity. Uptake of22Na into isolated MVM vesicles in the presence of a H+ gradient, at initial rate, was four- to fivefold higher than that by BM vesicles (214±28 vs. 49±9 pmol/mg protein per 30 s, respectively, means±SEM,n=8, 6,P<0.001). The22Na uptake by MVM, but not by BM, was reduced in the absence of a H+ gradient and in the presence of 500 µM amiloride. To determine the contribution of NHE1, NHE2 and NHE3 isoforms to NHE activity in MVM, we investigated the effect of amiloride analogues which show isoform selectivity. HOE 694, an analogue selective for NHE1 at low concentrations, inhibited22Na uptake with an EC50 of 0.13±0.05 µM (n=6), whereas S3226, an analogue selective for NHE3 at low concentrations had an EC50 of 3.01±0.85 µM (n=5). To investigate this further, we measured recovery of syncytiotrophoblast intracellular pH (pHi) from an acid load using a H+-selective, fluorescent dye (BCECF) loaded into isolated intact placental fragments. This recovery was blocked in the absence of Na+ and the presence of amiloride (500 µM) and concentrations of HOE 694 and S3226 were comparable to those used in vesicle experiments. Overall these data show that under the conditions used NHE activity in the term placental syncytiotrophoblast is absent from BM. NHE activity in the MVM is attributable predominantly to NHE1. [ABSTRACT FROM AUTHOR]

An abstract of the article "Nitric oxide derived free radicals impair placental amino-acid uptake: implications for fetal growth and programming" is presented. This study aims to understand the regulation of fetal growth in association of size during birth and morbidity in adulthood. The effect of nitric oxide on fetal growth was prevented through super-oxide dismutase or hemoglobin and suggests that the nitric acid-derived free radical peroxynitrite changed the transfer of placental nutrient.