Alveolar epithelial cells (A549) exposed at the air–liquid interface to diesel exhaust: First study in TNO’s powertrain test center

Air–liquid interface (ALI) exposures enable in vitro testing of mixtures of gases and particles such as diesel exhaust (DE). The main objective of this study was to investigate the feasibility of exposing human lung epithelial cells at the ALI to complete DE generated by a heavy-duty truck in the state-of-the-art TNO powertrain test center. A549 cells were exposed at the air–liquid interface to DE generated by a heavy-duty Euro III truck for 1.5 h. The truck was tested at a speed of ～70 km h^?1 to simulate free-flowing traffic on a motorway. Twenty-four hours after exposure, cells were analyzed for markers of oxidative stress (GSH and HO-1), cytotoxicity (LDH and Alamar Blue assay) and inflammation (IL-8). DE exposure resulted in an increased oxidative stress response (significantly increased HO-1 levels and significantly reduced GSH/GSSH ratio), and a decreased cell viability (significantly decreased Alamar Blue levels and slightly increased LDH levels). However, the pro-inflammatory response seemed to decrease (decrease in IL-8). The results presented here demonstrate that we are able to successfully expose A549 cells at ALI to complete DE generated by a heavy-duty truck in TNO’s powertrain test center and show oxidative stress and cytotoxicity responses due to DE exposure.     

Two-way calf to dam major histocompatibility class I compatibility increases risk for retained placenta in cattle

Citation
Benedictus L, Thomas AJ, Jorritsma R, Davies CJ, Koets AP. Two‐way calf to dam major histocompatibility class I compatibility increases risk for retained placenta in cattle. Am J Reprod Immunol 2012; 67: 224–230 Problem In cattle, retained placenta (RP) is suggested to arise from failure of immune‐mediated rejection of the fetal membranes by the maternal immune system and is associated with major histocompatibility (MHC) class I compatibility between calf and dam. Method of study To study the association between RP and different MHC class I compatibilities between calf–dam–granddam combinations, massively parallel pyrosequencing was used to determine the MHC class I haplotypes of cows with and without RP. Results Two‐way calf to dam MHC class I compatibility gave a high risk for RP. There was a tendency for a higher risk for RP with calf to dam MHC class I compatibility. Conclusions We concluded that in two‐way compatible pregnancies, the maternal immune system fails to reject the fetal membranes, and the fetal immune system does not mount an immune response against maternal MHC class I antigens that could influence the immune‐mediated rejection of the fetal membranes by the maternal immune system. The lack of immune‐mediated rejection of the fetal membranes by the maternal immune system increases the risk of occurrence of RP.     

Starch with high amylose content and low in vitro digestibility increases intestinal nutrient flow and microbial fermentation and selectively promotes bifidobacteria in pigs

Diets containing different starch types can affect enzymatic digestion of starch and thereby starch availability for microbial fermentation in the gut. However, the role of starch chemistry in nutrient digestion and flow and microbial profile has been poorly explained. Eight ileal-cannulated pigs (29.4 ± 0.9 kg body weight) were fed 4 diets containing 70% purified starch (amylose content, <5, 20, 28, and 63%; reflected by in vitro maximal digestion rate; 1.06, 0.73, 0.38, and 0.22%/min, respectively) in a replicated 4 × 4 Latin square. Ileal and fecal starch output, postileal crude protein yield, fecal total SCFA and total butyrate content, and gene copies of Bifidobacterium spp. in feces were higher (P < 0.05) when pigs consumed the slowly digestible starch diet than the remaining 3 starch diets. The in vitro starch digestion rate had a negative, nonlinear relationship with ileal starch flow (R(2) = 0.98; P < 0.001). Ileal starch flow was positively related to Bifidobacterium spp. (R(2) = 0.27; P < 0.01), Lactobacillus group (R(2) = 0.22; P < 0.01), and total butyrate content (R(2) = 0.46; P < 0.01) but was not related to Enterobacteriaceae (R(2) < 0.00; P = 0.92). In conclusion, starch with high amylose content and low in vitro digestibility increased postileal nutrient flow and microbial fermentation and selectively promoted Bifidobacterium spp. in the distal gut.     

Effects of viscosity and fermentability of dietary fibre on nutrient digestibility and digesta characteristics in ileal-cannulated grower pigs

Relative contributions of two functional properties, viscosity and fermentability of dietary fibre, on apparent ileal digestibility (AID), apparent total tract digestibility (ATTD), digesta passage rate, N retention and SCFA concentration have not been established. Thus, eight ileal-cannulated pigs randomised in a double 4 × 4 Latin square were fed four diets based on maize starch and casein supplemented with 5 % of actual fibre in a 2 × 2 factorial arrangement: low-fermentable, low-viscous cellulose (CEL); low-fermentable, high-viscous carboxymethylcellulose (CMC); high-fermentable, low-viscous oat β-glucan (LBG); high-fermentable, high-viscous oat β-glucan (HBG). Viscosity and fermentability interacted to affect (P < 0·001) digesta viscosity and AID and ATTD of nutrients. These properties tended to interact to affect (P < 0·10) digesta passage rate and butyrate. Pigs fed the CMC diet had the lowest (P < 0·05) digesta passage rate and the highest (P < 0·001) AID of energy, crude protein and DM, and ATTD of energy and DM. Post-ileal DM digestibility was highest (P < 0·001) for pigs fed the CEL and HBG diets. Post-ileal DM digestibility had a negative, curvilinear relationship with the AID of energy and crude protein (R2 0·85 and 0·72, respectively; P < 0·001). Digesta viscosity had a less strong relationship with the AID of energy and crude protein (R2 0·45 and 0·36, respectively; P < 0·001). In conclusion, high-viscous, low-fermentable dietary fibre increases the proportion of a diet that is digested in the small intestine by reducing digesta passage rate.     

Starch with high amylose and low in vitro digestibility increases short-chain fatty acid absorption, reduces peak insulin secretion, and modulates incretin secretion in pigs

Diets containing different starch types affect peripheral glucose and insulin responses. However, the role of starch chemistry in kinetics of nutrient absorption and insulin and incretin secretion is poorly understood. Four portal vein-catheterized pigs (35.0 ± 0.2 kg body weight) consumed 4 diets containing 70% purified starch [0-63.2% amylose content and 0.22 (slowly) to 1.06%/min (rapidly) maximum rate of in vitro digestion] for 7-d periods in a 4 × 4 Latin square. On d 7, blood was collected for 12 h postprandial with simultaneous blood flow measurement for determining the net portal appearance (NPA) of nutrients and hormones. The NPA of glucose, insulin, C-peptide, and glucose-dependent insulinotropic polypeptide (GIP) during 0-4 h postprandial were lower (P < 0.05) and those of butyrate and total SCFA were higher (P < 0.05) when pigs consumed the diet containing slowly digestible compared with rapidly digestible starch. The peak NPA of insulin occurred prior to that of glucose when pigs consumed diets containing rapidly digestible starch. The kinetics of insulin secretion had a linear positive relation with kinetics of NPA of glucose (R(2) = 0.50; P < 0.01). In conclusion, starch with high amylose and low in vitro digestibility decreases the kinetics of glucose absorption and insulin and GIP secretion and increases SCFA absorption and glucagon-like peptide-1 secretion. In conclusion, starch with high amylose content and a lower rate and extent of in vitro digestion decreased glucose absorption and insulin secretion and increased SCFA absorption.     

Glutamine-enriched enteral nutrition in very low birthweight infants and allergic and infectious diseases at 6 years of age

In a previous randomised controlled trial, we found that glutamine-enriched enteral nutrition in 102 very low birthweight (VLBW) infants decreased both the incidence of serious infections in the neonatal period and the risk of atopic dermatitis during the first year of life. We hypothesised that glutamine-enriched enteral nutrition in VLBW infants in the neonatal period influences the risk of allergic and infectious disease at 6 years of age. Eighty-eight of the 102 infants were eligible for the follow-up study (13 died, 1 chromosomal abnormality). Doctor-diagnosed allergic and infectious diseases were assessed by means of validated questionnaires. The association between glutamine-enriched enteral nutrition in the neonatal period and allergic and infectious diseases at 6 years of age was based on univariable and multivariable logistic regression analyses. Seventy-six of the 89 (85%) infants participated, 38 in the original glutamine-supplemented group and 38 in the control group. After adjustment, we found a decreased risk of atopic dermatitis in the glutamine-supplemented group: adjusted odds ratio (aOR) 0.23 [95% CI 0.06, 0.95]. No association between glutamine supplementation and hay fever, recurrent wheeze and asthma was found. A decreased risk of gastrointestinal tract infections was found in the glutamine-supplemented group (aOR) 0.10 [95% CI 0.01, 0.93], but there was no association with upper respiratory, lower respiratory or urinary tract infections. We concluded that glutamine-enriched enteral nutrition in the neonatal period in VLBW infants decreased the risk of atopic dermatitis and gastrointestinal tract infections at 6 years of age.     

Analysis of a case of internal contamination with 242Cm

During the preparation of targets for the mass spectrometer some 242Cm escaped from the preparation box resulting in a contamination of the laboratory air and of subsequent ingestion of radioactivity by the technician concerned. Nose wipe tests were taken immediately after the incident and faecal and urine samples during the following week. Air sampling filters located in three places in the laboratory were changed immediately and then at regular intervals. The size distribution of the particles was calculated from autoradiographs made from the filter samples. From the results of these analyses the quantity ingested in the respiratory tract was determined using the ICRP "Lung Model" as a guide. The distribution of the ingested material in the body organs was then estimated from the data in Publication 2 (1959) of the ICRP. Although the quantities involved predicted an internal contamination far below the maximum permissible values, this detailed analysis was carried out as an opportunity for testing the "Lung Model" in the case of Curium inhalation. Interpretation and comparison of air filter sampling data with results of nose wipe and faecal tests suggest that the ICRP lung model may serve as a useful guide to estimate the approximate level of an internal contamination after inhalation exposure to 242Cm.     

Isolation of epidemic poliovirus from sewage during the 1992-3 type 3 outbreak in The Netherlands.

To examine the extent of wild poliovirus circulation during the 1992-3 epidemic in the Netherlands caused by poliovirus type 3, 269 samples from sewage pipelines at 120 locations were examined for the presence of poliovirus. The epidemic virus strain was found in 23 samples, all from locations inside the risk area which contained communities that refuse vaccination for religious reasons. By sewage investigation, the wildtype virus was shown to be present in the early phase of the epidemic at two locations, one week before patients were reported from that area. The wild type 3 poliovirus was also detected retrospectively in a river water sample collected for other reasons three weeks before notification of the first poliomyelitis case, at a site a few kilometres upstream the home village of this patient. Oral poliovirus vaccine (OPV) virus was found at 28 locations inside or at the border of the risk area. Trivalent OPV was offered to unvaccinated or incompletely-vaccinated persons living in this region as part of the measures to control the epidemic.