Association between days post conception and lactation persistency in dairy cattle

Determining the optimal insemination moment for individual cows is complex, particularly when considering the impact of pregnancy on milk production. The effect of pregnancy on the absolute milk yield has already been reported in several studies. Currently, there is limited quantitative knowledge about the association between days post conception (DPC) and lactation persistency, based on a lactation curve model, and, specifically, how persistency changes during pregnancy and relates to the days in milk at conception (DIMc). Understanding this association might provide valuable insights to determine the optimal insemination moment. This study, therefore, aimed to investigate the association between DPC and lactation persistency, with an additional focus on the influence of DIMc. Available milk production data from 2005 to 2022 were available for 23,908 cows from 87 herds located throughout the Netherlands and Belgium. Persistency was measured by a lactation curve characteristic decay, representing the time taken to halve milk production after peak yield. Decay was calculated for 8 DPC (0, 30, 60, 90, 120, 150, 180 and 210 d after DIMc) and served as the dependent variable. Independent variables included DPC, DIMc (< = 60, 61-90, 91-120, 121-150, 151-180, 181-210, > 210), parity group, DPC × parity group, DPC × DIMc and variables from 30 d before DIMc as covariates. The results showed an increase in decay, i.e., a decrease in persistency, during pregnancy for both parity groups, albeit in different ways. Specifically, from DPC 150 to DPC 210, multiparous cows showed a higher decline in persistency compared with primiparous cows. Furthermore, a later DIMc (cows conceiving later) was associated with higher persistency. Except for the early DIMc groups (DIMc < 90), DIMc does not impact the change in persistency by gestation. The findings from this study contribute to a better understanding of how DPC and DIMc during lactation influence lactation persistency, enabling more informed decision-making by farmers who wish to take persistency into account in their reproduction management.

Development and evaluation of uncertainty quantifying machine learning models to predict piperacillin plasma concentrations in critically ill patients

BACKGROUND

Beta-lactam antimicrobial concentrations are frequently suboptimal in critically ill patients. Population pharmacokinetic (PopPK) modeling is the golden standard to predict drug concentrations. However, currently available PopPK models often lack predictive accuracy, making them less suited to guide dosing regimen adaptations. Furthermore, many currently developed models for clinical applications often lack uncertainty quantification. We, therefore, aimed to develop machine learning (ML) models for the prediction of piperacillin plasma concentrations while also providing uncertainty quantification with the aim of clinical practice.

METHODS

Blood samples for piperacillin analysis were prospectively collected from critically ill patients receiving continuous infusion of piperacillin/tazobactam. Interpretable ML models for the prediction of piperacillin concentrations were designed using CatBoost and Gaussian processes. Distribution-based Uncertainty Quantification was added to the CatBoost model using a proposed Quantile Ensemble method, useable for any model optimizing a quantile function. These models are subsequently evaluated using the distribution coverage error, a proposed interpretable uncertainty quantification calibration metric. Development and internal evaluation of the ML models were performed on the Ghent University Hospital database (752 piperacillin concentrations from 282 patients). Ensuing, ML models were compared with a published PopPK model on a database from the University Medical Centre of Groningen where a different dosing regimen is used (46 piperacillin concentrations from 15 patients.).

RESULTS

The best performing model was the Catboost model with an RMSE and [Formula: see text] of 31.94-0.64 and 33.53-0.60 for internal evaluation with and without previous concentration. Furthermore, the results prove the added value of the proposed Quantile Ensemble model in providing clinically useful individualized uncertainty predictions and show the limits of homoscedastic methods like Gaussian Processes in clinical applications.

CONCLUSIONS

Our results show that ML models can consistently estimate piperacillin concentrations with acceptable and high predictive accuracy when identical dosing regimens as in the training data are used while providing highly relevant uncertainty predictions. However, generalization capabilities to other dosing schemes are limited. Notwithstanding, incorporating ML models in therapeutic drug monitoring programs seems definitely promising and the current work provides a basis for validating the model in clinical practice.

Fatty Acid Supplementation During in vitro Embryo Production Determines Cryosurvival Characteristics of Bovine Blastocysts

In vitro production (IVP) embryos have a reduced quality and poor cryotolerance in comparison to in vivo embryos. This study investigated whether free fatty acid (FFA) conditions, fatty acid free (FAF)- synthetic oviduct fluid (SOF) without or with 25 μM of saturated stearic (C_18:0) or unsaturated oleic (C_18:1) acid during the first 5 IVP days, relate to quality and cryosurvival of day 8 blastocysts. Apart from the blastocyst scores, both 1) number and size of lipid droplets of fresh blastocysts and 2) total number and apoptotic and necrotic cells, before and after freezing-thawing, were scored by confocal microscopy. Blastocyst rates were significantly lower in the FAF SOF condition in comparison to other groups. Interestingly, blastocysts originating from the C_18:1 group, with a significantly higher lipid content, and blastocysts from the FAF SOF group demonstrated a high cryosurvival rate (70.1 and 67.4%, respectively) comparable with in vivo blastocysts (68%), in contrast to the poor cryosurvival of C_18:0 exposed embryos (17.6%). In all freeze-thawed embryos the average amount of apoptotic and necrotic cells increased albeit that the C_18:0 condition rates were higher (43.2%) when compared to C_18:1 (26.0%) and FAF SOF conditions (26.5%). The current data show that FFA administered during early embryonic development significantly affect the cryotolerance of blastocysts.

Reproductive hormone use and its association with herd-level factors on Dutch dairy farms

We studied the use of the 3 commonly used reproductive hormones, namely prostaglandins, GnRH, and progesterone, and associated herd-level factors on 760 Dutch dairy farms from 5 veterinary clinics. From 2017 to 2019 we collected data on the sales of reproductive hormones, converted this data into the number of reproductive hormone doses conducted, and expressed this as the annual number of reproductive hormone doses per 100 adult dairy cows. Additional herd-level information was available for 2019. Due to the excess of zeros in the data set (i.e., a substantial number of farms did not use any hormones), we used a zero-inflated negative binomial model to identify related herd-level factors for the use of reproductive hormones. In the entire study period of 2017 to 2019, 5.8% of the dairy farms did not use any reproductive hormones, with the proportion of nonusers varying between 0.0 and 10.3% per veterinary clinic. This proportion was around 13.5% on an annual basis. Prostaglandins were the most frequently used reproductive hormone in Dutch dairy cows (62.9%), followed by GnRH (33.1%) and progesterone (4.0%). Furthermore, participating in a veterinary herd health management program had a significant effect on reproductive hormone use. These farms used more reproductive hormones than farms that did not participate in a herd health management program and were less represented in the group of nonuser farms. Technologies, such as pedometers and automatic milking systems, also had an effect on reproductive hormone use. The presence of pedometers or activity monitors did not reduce the use of the reproductive hormones but was associated with a greater frequency of users. Farms with an automatic milking system used more reproductive hormones than farms with a conventional milking system. With this study, we have made a first step in achieving transparency in the Dutch dairy industry by providing an objective overview of reproductive hormone use on Dutch dairy farms and identifying associations with some herd-level factors.

Continuous versus intermittent infusion of cefotaxime in critically ill patients: a randomized controlled trial comparing plasma concentrations

BACKGROUND

In critical care patients, reaching optimal β-lactam concentrations poses challenges, as infections are caused more often by microorganisms associated with higher MICs, and critically ill patients typically have an unpredictable pharmacokinetic/pharmacodynamic profile. Conventional intermittent dosing frequently yields inadequate drug concentrations, while continuous dosing might result in better target attainment. Few studies address cefotaxime concentrations in this population.

OBJECTIVES

To assess total and unbound serum levels of cefotaxime and an active metabolite, desacetylcefotaxime, in critically ill patients treated with either continuously or intermittently dosed cefotaxime.

METHODS

Adult critical care patients with indication for treatment with cefotaxime were randomized to treatment with either intermittent dosing (1 g every 6 h) or continuous dosing (4 g/24 h, after a loading dose of 1 g). We defined a preset target of reaching and maintaining a total cefotaxime concentration of 4 mg/L from 1 h after start of treatment. CCMO trial registration number NL50809.042.14, Clinicaltrials.gov NCT02560207.

RESULTS

Twenty-nine and 30 patients, respectively, were included in the continuous dosing group and the intermittent dosing group. A total of 642 samples were available for analysis. In the continuous dosing arm, 89.3% met our preset target, compared with 50% in the intermittent dosing arm. Patients not reaching this target had a significantly higher creatinine clearance on the day of admission.

CONCLUSIONS

These results support the application of a continuous dosing strategy of β-lactams in critical care patients and the practice of therapeutic drug monitoring in a subset of patients with higher renal clearance and need for prolonged treatment for further optimization, where using total cefotaxime concentrations should suffice.

149 Uptake of C18:0 from culture media during invitro culture decreases cryosurvival rates of bovine embryos

Cryosurvival of invitro-produced bovine embryos is lower than that of invivo-produced embryos, limiting their usability in the field. Previous work showed that the embryo’s lipid composition relates to its quality and cryosurvival. The present study aimed to investigate the effects of free fatty acid (FA) additions to embryo culture media during the oviduct phase of embryonic development on the improvement of cryosurvival of invitro-produced blastocysts. Bovine cumulus–oocyte complexes (n=1675, 3 replicates) were harvested from slaughterhouse ovaries, invitro matured (23h), and subsequently fertilized (18–20h). Embryos were cultured until Day 5 post-fertilization in synthetic oviductal fluid (SOF) with (1) bovine serum albumin (BSA; control, n=253); (2) delipidified BSA (&gt;96% FA free, n=460); (3), delipidified BSA complexed with 25µM unsaturated oleic acid (C18:1, n=455); or (4) with saturated stearic acid (C18:0, n=507) with a stoichiometry of 5:1. At Day 5, SOF was refreshed and embryos were cultured without supplementation. At Days 7 and 8, blastocyst rates were determined. Blastocysts were LD540 stained for lipid droplets (LD), and the LD number and size were analysed by ANOVA. Cryosurvival%, defined by re-expansion of the blastocoel, was analysed by logistic regression. Additionally, fresh and frozen–thawed blastocysts were stained for apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labelling, TUNEL), necrosis (EthD-1), and DNA (Hoechst 33342) and analysed using negative binomial regression. Group differences were tested using a post hoc Tukey test. Statistical analysis was performed in R Studio (version 3.4.2), and P-values &lt;0.05 were considered significant. FA-free culture delayed and decreased blastocyst rates to 19% compared with any FA supplementation: 35%, 27%, and 29% for control, C18:1, and C18:0, respectively (P&lt;0.04). Cryosurvival doubled with culture in FA-free SOF (58%) and C18:1 (63%) compared with C18:0 (23% P=0.01 and P&lt;0.01, respectively) and control (29%; P=0.15 and P&lt;0.02, respectively), approaching cryosurvival rates of donated multiple ovulation embryo transfer (MOET) embryos (CRV Company; 67%). C18:0 exposure also resulted in elevated necrosis levels after cryopreservation (5–8% of cells), compared with all groups (2–4%; P&lt;0.016). The LD size increased in blastocysts cultured with C18:1 compared with all groups (3.1µm2 vs. 2.4–2.7µm2; P&lt;0.016). C18:0 addition to SOF during embryo culture invitro, as well as a mixture of FA in control SOF (including C18:0), caused a reduction of ∼50% in blastocyst cryosurvival compared with MOET blastocysts. Interestingly, either C18:1 addition or the complete omission of FA in SOF during embryo culture invitro restored the cryosurvival of blastocysts to the level of MOET blastocysts. Currently, we are investigating whether the free FA conditions in the oviduct endorse the distinct quality between invivo- and invitro-produced embryos.

Marked Changes in Gut Microbiota in Cardio-Surgical Intensive Care Patients: A Longitudinal Cohort Study

Background: Virtually no studies on the dynamics of the intestinal microbiota in patients admitted to the intensive care unit (ICU) are published, despite the increasingly recognized important role of microbiota on human physiology. Critical care patients undergo treatments that are known to influence the microbiota. However, dynamics and extent of such changes are not yet fully understood. To address this topic, we analyzed the microbiota before, during and after planned major cardio surgery that, for the first time, allowed us to follow the microbial dynamics of critical care patients. In this prospective, observational, longitudinal, single center study, we analyzed the fecal microbiota using 16S rRNA gene sequencing.

Results: Samples of 97 patients admitted between April 2015 and November 2016 were included. In 32 patients, data of all three time points (before, during and after admission) were available for analysis. We found a large intra-individual variation in composition of gut microbiota. During admission, a significant change in microbial composition occurred in most patients, with a significant increase in pathobionts combined with a decrease in strictly anaerobic gut bacteria, typically beneficial for health. A lower bacterial diversity during admission was associated with longer hospitalization. In most patients analyzed at all three time points, the change in microbiota during hospital stay reverted to the original composition post-discharge.

Conclusions: Our study shows that, even with a short ICU stay, patients present a significant change in microbial composition shortly after admission. The unique longitudinal setup of this study displayed a restoration of the microbiota in most patients to baseline composition post-discharge, which demonstrated its great restorative capacity. A relative decrease in benign or even beneficial bacteria and increase of pathobionts shifts the microbial balance in the gut, which could have clinical relevance. In future studies, the microbiota of ICU patients should be considered a good target for optimisation.

196 Steroid concentrations in bovine follicular fluid are affected by metabolic stress

The negative energy balance (NEB) in dairy cows, early postpartum, is related to reduced fertility. A metabolic characteristic of NEB is elevated levels of free fatty acids (NEFA) in blood and follicular fluid with an effect on the cumulus-oocyte complex (COC; Leroy et al. 2005 Reproduction 130, 485-495, https://doi.org/10.1530/rep.1.00735; Aardema et al. 2011 Biol. Reprod. 85, 62-69, https://doi.org/10.1095/biolreprod.110.088815; Aardema et al. 2013 Biol. Reprod. 88, 164, https://doi.org/10.1095/biolreprod.112.106062). In this study, we investigated the effect of elevated NEFA levels on granulosa cells and consequently steroid production during NEB. Both 17β-oestradiol (E2) and progesterone (P4) levels in follicular fluid and oocyte competence were measured during NEB, as oocyte competence and steroid production are related (Aardema et al. 2013 Theriogenology 80, 576-583, https://doi.org/10.1016/j.theriogenology.2013.05.025). Heifers were directed towards a control (CTR; n=6) or NEB group (NEB; n=6; fasting heifer model; Jorritsma et al. 2003 Theriogenology). Cycle synchronization and superstimulation were performed as previously reported; invivo matured oocytes were, by ovariectomy at 22h after the induced LH peak, individually collected from follicles (≥8 to ≤20mm) and invitro fertilized and cultured until Day 8. Levels of nonesterified fatty acids (NEFAs) in follicular fluid were, in CTR, 80μM palmitic (C16:0), 70μM stearic (C18:0), and 100μM oleic acid (C18:1) and, in NEB, 150μM C16:0, 100μM C18:0, and 200μM C18:1 (Aardema et al. 2013 Biol. Reprod. Vol, page range). Follicular fluid of individual follicles was frozen and stored at −20°C until E2 and P4 radioimmunoassay analysis. At Day 5 and 8 of culture, embryos were scored for developmental competence, according to Aardema et al. (2013 Biol. Reprod. Vol, page range). Oocytes developing to a blastocyst all originated from follicles with, formerly in control animals defined, optimal follicular fluid levels of E2 ≤0.25 μM and P4 ≥0.26 μM (Aardema et al. 2013 Theriogenology 80, 576-583, https://doi.org/10.1016/j.theriogenology.2013.05.025). Overall E2 levels in follicular fluid in NEB appeared to be lower than those in CTR. There was a reduced positive value of 0.33 (vs. 0.49 in CTR) for predicting the competence of oocytes to develop into a blastocyst, and reduced specificity of 0.26 (vs. 0.75 in CTR) for oocytes originating from follicles with optimal steroid levels in NEB. The sensitivity and negative predictive value were 1.0 in both NEB and CTR. Levels of P4 in follicular fluid were unaffected by NEB. The lower level of E2 indicates an effect of NEB on steroid synthesis in granulosa cells. Recently, it was demonstrated that invitro exposure to monounsaturated C18:1, in contrast to saturated C16:0 or C18:0, resulted in reduced E2 production and expression of CYP19A1 in granulosa cells (Sharma 2018 Endocrine Connections 8, 493-505, https://doi.org/10.1530/EC-19-0011). These data suggest that elevated levels of NEFAs, C18:1 in particular, affect the function of granulosa cells and the follicular steroid environment of the COC, in contrast to the effect of C18:1 on the COC, which appears to protect the oocyte against lipotoxic events by saturated NEFAs by massive lipid accumulation in cumulus cells (Aardema et al. 2011 Biol. Reprod. 85, 62-69, https://doi.org/10.1095/biolreprod.110.088815; Aardema et al. 2013 Biol. Reprod. 88, 164, https://doi.org/10.1095/biolreprod.112.106062). Elevated levels of C18:1 may also result in increased lipid storage in granulosa cells and could affect the steroid synthesis of cholesterol that is also stored in lipid droplets. How elevated NEFA levels during the NEB affect granulosa cells is under investigation.

Target attainment with continuous dosing of piperacillin/tazobactam in critical illness: a prospective observational study

Optimal dosing of β-lactam antibiotics in critically ill patients is a challenge given the unpredictable pharmacokinetic profile of this patient population. Several studies have shown intermittent dosing to often yield inadequate drug concentrations. Continuous dosing is an attractive alternative from a pharmacodynamic point of view. This study evaluated whether, during continuous dosing, piperacillin concentrations reached and maintained a pre-defined target in critically ill patients. Adult patients treated with piperacillin by continuous dosing in the intensive care unit of a university medical centre in The Netherlands were prospectively studied. Total and unbound piperacillin concentrations drawn at fixed time points throughout the entire treatment course were determined by liquid chromatography-tandem mass spectrometry. A pharmacokinetic combined target of a piperacillin concentration ≥80 mg/L, reached within 1 h of starting study treatment and maintained throughout the treatment course, was set. Eighteen patients were analysed. The median duration of monitored piperacillin treatment was 60 h (interquartile range, 33-96 h). Of the 18 patients, 5 (27.8%) reached the combined target; 15 (83.3%) reached and maintained a less strict target of >16 mg/L. In this patient cohort, this dosing schedule was insufficient to reach the pre-defined target. Depending on which target is to be met, a larger initial cumulative dose is desirable, combined with therapeutic drug monitoring.

Burden of highly resistant microorganisms in a Dutch intensive care unit

BACKGROUND

The occurrence of highly resistant microorganisms (HRMOs) is a major threat to critical care patients, leading to worse outcomes, need for isolation measures, and demand for second-line or rescue antibiotics. The aim of this study was to quantify the burden of HRMOs in an intensive care unit (ICU) for adult patients in a university hospital in the Netherlands. We evaluated local distribution of different HRMO categories and proportion of ICU-imported versus ICU- acquired HRMOs. Outcome of HRMO-positive patients versuscontrols was compared.

METHODS

In this prospective single-centre study, culture results of all ICU patients during a four-month period were recorded, as well as APACHE scores, ICU mortality and length of stay (LOS) in the ICU.

RESULTS

58 of 962 (6.0%) patients were HRMO positive during ICU stay. The majority (60%) of those patients were HRMO positive on ICU admission. HRMO-positive patients had significantly higher APACHE scores, longer LOS and higher mortality compared with controls.

CONCLUSIONS

Our study suggests that a large part of antibiotic resistance in the ICU is imported. This underscores the importance of a robust surveillance and infection control program throughout the hospital, and implies that better recognition of those at risk for HRMO carriage before ICU admission may be worthwhile. Only a small minority of patients with HRMO at admission did not have any known risk factors for HRMO.

1 CUMULUS CELLS PROTECT OOCYTES AGAINST POTENTIAL LIPOTOXICITY FROM ELEVATED FREE FATTY ACID CONCENTRATIONS IN FOLLICULAR FLUID

Metabolic conditions characterized by elevated free fatty acid levels in the blood are often associated with reduced fertility performance. Increased concentrations of saturated free fatty acids can induce lipotoxicity in cumulus–oocyte-complexes in vitro, while unsaturated fatty acids like oleic acid are mostly harmless and able to counteract the impact of saturated fatty acids (Aardema et al. 2011 Biol. Reprod. 85, 62–69). This study investigates the impact of elevated free fatty acids in the blood on the follicular fluid and the lipid of cumulus and oocytes derived from these follicles. Furthermore, in vitro maturing oocytes were exposed to free fatty acid concentrations measured in follicles of control and metabolically stressed animals from this study to determine the impact on oocyte developmental competence. Cyclic heifers (n = 12) were synchronized (7 days CIDR®) and superstimulated from Day 10 of the synchronized cycle [4 days of Folltropin-V® (Bioniche Animal Health Inc., Belleville, ON, Canada) in decreasing doses; in total 200 mg]. Heifers received ad libitum grass silage, apart from the experimental group (n = 6), which was metabolically stressed during the period of superstimulation. Ovaries were collected by ovariectomy at final maturation, 22 h after the induced LH peak. Follicular fluids and cumulus–oocyte complexes (COC) were collected from follicles of ≥8 mm. To determine the free fatty acid and lipid composition, blood, follicular fluid, cumulus cells, and oocytes were analyzed with mass spectrometry. The COC (4 runs, 400 per group) derived from slaughterhouse ovaries were in vitro matured in a standard medium without or with the dominating free fatty acids, saturated palmitic and stearic and unsaturated oleic acid, in concentrations measured in follicular fluid of control (80, 70, and 100 µM) and experimental heifers (150, 100, and 200 µM) and fertilized and cultured until the blastocyst stage. Culture data were analyzed by one-way ANOVA and lipid data by two-sample t-test (P ≤ 0.05 considered significant). Procedures were approved by the Institutional Animal Care and Use Committee. Metabolic stress resulted in elevated free fatty acid levels in blood (from 430 ± 70 to 1048 ± 190 µM) and follicular fluid (from 357 ± 72 to 670 ± 133 µM), with relatively high oleic acid concentrations in follicular fluid (+10%). The increased levels of free fatty acids in follicular fluid resulted in a massive increase of fatty acids in the cumulus cells, but oocytes did only show marginal changes. In line with this, maturation in the presence of elevated palmitic, stearic, and oleic acid did not impair oocyte developmental competence and resulted in comparable blastocyst rates for the standard medium and the free fatty acid control and metabolic stress medium (31 ± 8.7, 34 ± 7.8, and 28 ± 1.7%). Thus, cumulus cells appear to protect oocytes against potential lipotoxicity from elevated free fatty acid concentrations by the accumulation of these fatty acids. This work was funded by Pfizer Animal Health.

175 METABOLIC STRESS IMPAIRS FOLLICULAR GROWTH IN SUPEROVULATED HEIFERS

Metabolic stress during the early postpartum period has been postulated to be one of the major causes of prolonged calving intervals. To study the impact of metabolic stress on ovarian follicular function via hormonal analysis of follicular fluid and follicular growth, 12 cycling heifers were randomly allocated to a group (n = 6) that received a control diet (ad libitum grass silage) or to an experimental group (n = 6) that was fasted during the superovulation (SO) treatment for 4 days until ovariectomy (Jorritsma et al. 2003 Theriogenology 60, 151–161). Heifers were synchronized with a CIDR® intravaginal device (Pfizer AH) during 7 days, and a prostaglandin injection (5 mL Enzaprost® CEVA AH) was administered 1 day before CIDR® removal. On day 9 of the synchronized cycle, the dominant follicle of the first follicular wave was removed and the standard SO protocol was started 2 days later (twice daily decreasing doses for 4 days, total 200 mg of Folltropin-V®, Bioniche AH). Cows received a CIDR® device during SO to suppress a spontaneous LH surge. To collect ovarian tissue at 22 h after the LH peak by ovariectomy, a controlled LH surge was induced by a GnRH injection (1 mg of Fertagyl® Intervet SP AH) at the time of CIDR® removal (Vos et al. 1994 J. Reprod. Fertil. 100, 387–393). Ovaries were transported to the laboratory at 37°C directly after ovariectomy. For each animal, follicular growth was determined by counting the number of follicles >8 mm in diameter (defined as presumptive follicles). The size category of follicles was based on the volume collected after puncturing (8 to 10 mm, 10 to 12 mm, >12 mm). To determine the quality of the follicle, follicular fluid of each individual follicle was analyzed for estradiol (E2) and progesterone (P4) concentrations. Healthy follicles at 22 h after the LH peak were defined as follicles showing low E2 and high P4 >0.5 μmol L–1 (E2/P4<1; Dieleman et al. 1983 J. Endocrinol. 97, 31–42). Statistical analysis was performed by logistic regression for grouped data (P < 0.05; mean ± SEM). The total number of follicles per animal (follicles >8 mm in diameter) did not differ between the control (18 ± 2.8) and fasted group (19.8 ± 2.9). However, the number of large follicles (>12mm) that developed in the fasted heifers was significantly lower (2.7 ± 0.9) compared with that in the control heifers (6.0 ± 1.7). No difference was observed for the percentage of healthy follicles per animal between fasted (32 ± 9.2%) and control (56 ± 13%) heifers. These data show that follicular growth was impaired during SO treatment in fasted heifers. Although not significantly different, a numerically lower number of healthy follicles was observed in the fasted group of heifers, possibly indicating a negative influence of metabolic stress on follicular function. Whether metabolic stress affects the metabolic composition of the follicular fluid and as a consequence influences oocyte and embryo quality is under current investigation. Project is sponsored by Pfizer Animal Health.

327 UNSATURATED AND SATURATED NON-ESTERIFIED FATTY ACIDS DIFFERENTLY AFFECT LIPID STORAGE AND DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES

Fertility in high-producing dairy cows has declined over the last decades. An increased serum and follicular fluid concentration of non-esterified fatty acids (NEFAs), due to body fat mobilization in the early post partum period, has been postulated as a cause for this fertility decline. NEFA concentrations and composition may change in the environment of the oocyte and thus might affect the storage depots of esterified NEFAs in the oocyte. We exposed COCs to unsaturated (oleic acid) or saturated (palmitic acid) NEFAs during maturation and subsequently examined lipid droplets and developmental competence of the oocytes. COCs from 3-8 mm follicles of slaughterhouse ovaries were cultured in control maturation medium (TCM-199) and medium containing 100, 250, or 500 μM oleic and/or palmitic acid (10 mM fatty acid was bound to 10% BSA fatty acid free). These concentrations were based on in vivo measured NEFA concentrations in follicular fluid in the early post partum period (Leroy et al. 2005 Reproduction 130, 485-495). After 23 h of maturation, COCs were fertilized (450 per group) and cultured till the blastocyst stage, or fixed (80 per group) for lipid droplet staining with C1-BODIPY® 500/510 C12. Confocal microscopy was performed to determine lipid droplet size in (im(mean) and the number of lipid droplets per oocyte. Lipid droplet number and the log of size were analyzed using analysis of variances with condition as fixed factor. Variation was described as the standard error of the mean. Similar concentrations of palmitic or oleic acid had an opposite effect on the size of lipid droplets in oocytes. The number of lipid droplets dramatically decreased in oocytes exposed to 500 μM palmitic acid (178 ± 20), whereas the number increased after exposure to 500 μM oleic acid (554 ± 15). The number of lipid droplets of oocytes exposed to a combination of 250 μM palmitic acid and 250 μM oleic acid (421 ± 23) was comparable with the control and lower oleic and palmitic acid concentrations. Exposure of COCs to palmitic acid during maturation resulted in reduced blastocyst development in a dose-dependent manner (from 18 ± 1.4%, 13 ± 2.4% to 2.8 ± 1.3% after exposure to 500 μM) when compared to control (20 ± 2.2%) or oocytes exposed to oleic acid (from 23 ± 1.6%, 23 ± 3.3% till 28 ± 3.3%). Negative effects of palmitic acid were counteracted by simultaneous exposure to oleic acid during in vitro oocyte maturation (26 ± 5.5%). We conclude that palmitic acid elicited negative effects on early embryonic development, possibly because it induces a reduction in the number of lipid droplets. These adverse effects can be offset by oleic acid during maturation. Moreover a high oleic acid concentration increased the number and size of lipid droplets of oocytes. The regulatory pathways involved in the noted differences in lipid storage features of in vitro-matured oocytes as well as the adverse effects of palmitic acid on early embryonic development are currently under research.

[Fatal pneumonitis due to oseltamivir-resistant new influenza A(H1N1) in the case of an intensive care patient]

A 58-year-old man was submitted to our intensive care ward with respiratory failure due to pneumonitis. He had previously been treated for non-Hodgkin lymphoma by autologous stem cell transplantation, as a result of which bone marrow function was reduced. Further analysis showed infection with new influenza A(H1N1); typing revealed an oseltamivir-resistant subpopulation (H275Y). The patient was treated with oseltamivir and intravenously with zanamivir, but died of respiratory disease progression. This is the first published case of oseltamivir-resistant new influenza A(H1N1) infection in the Netherlands.

[Diagnostic image. A woman with a swollen tongue]

A 46-year-old woman had a swollen tongue due to amyloid light chain (AL) amyloidosis caused by multiple myeloma.

Organophosphorus pesticide poisoning: cases and developments

Self-poisoning with organophosphate pesticides is a major health problem world-wide. Through the inhibition of acetylcholinesterase, organophosphorus poisoning is characterised by the clinical picture of acute cholinergic crisis. Other manifestations are the intermediate neurotoxic syndrome and delayed polyneuropathy. In the Western world, the occurrence of organophosphorus poisoning is less prevalent due to the declining availability of organophosphate pesticides, which could render the recognition of this particular type of intoxication and its specific treatment more difficult. In this article we discuss some recent developments and treatment dilemmas, illustrated by cases from our clinic, followed by a review of the current recommendations in the treatment of organophosphate poisoning.

Changing epidemiology of melioidosis? A case of acute pulmonary melioidosis with fatal outcome imported from Brazil

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is endemic in South East Asia and tropical regions of Northern Australia. Sporadic cases have been described elsewhere. In this article we present a case of acute pulmonary melioidosis with fatal outcome imported from Brazil. The most common pathogen causing severe community-acquired pneumonia in Brazil is Streptococcus pneumoniae. Other possible pathogens include Legionella spp., Mycoplasma pneumonia, Gram-negative rods and viruses. There are few reports of melioidosis in the Americas. This article represents the second known human case of melioidosis from Brazil. Recognition of melioidosis as a possible cause of severe pneumonia, even if a patient has not been travelling in a highly endemic area, is important because of the therapeutic consequences. The epidemiology of melioidosis will be reviewed.