A Pharmacy-Based eHealth Intervention Promoting Correct Use of Medication in Patients With Asthma and COPD: Nonrandomized Pre-Post Study.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) affect millions of people worldwide. While medication can control and improve disease symptoms, incorrect use of medication is a common problem. The eHealth intervention SARA (Service Apothecary Respiratory Advice) aims to improve participants' correct use of inhalation medication by providing information and as-needed tailored follow-up support by a pharmacist. OBJECTIVE: The primary aim of this study was to investigate the effect of SARA on exacerbation rates in participants with asthma and COPD. Secondary aims were to investigate its effects in terms of adherence to maintenance medication and antimycotic treatment. METHODS: In this nonrandomized pre-post study, medication dispensing data from 382 Dutch community pharmacies were included. Exacerbation rates were assessed with dispensed short-course oral corticosteroids. Medication adherence between new and chronic users was assessed by calculating the proportion of days covered from dispensed inhalation maintenance medication. Antimycotic treatment was investigated from dispensed oral antimycotics in participants who were also dispensed inhaled corticosteroids (ICS). Outcomes were assessed 1 year before and 1 year after implementation of SARA and were compared between SARA participants and control participants. More specifically, for exacerbation rates and medication adherence, a difference score was calculated (ie, 1 year after SARA minus 1 year before SARA) and was subsequently compared between the study groups with independent-samples t tests. For antimycotics, the relative number of participants who were dispensed antimycotics was calculated and subsequently analyzed with a mixed-effects logistic regression. RESULTS: The study population comprised 9452 participants, of whom 2400 (25.39%) were SARA participants. The mean age of the population was 60.8 (15.0) years, and approximately two-thirds (n=5677, 60.06%) were female. The results showed an increase in mean exacerbation rates over time for both study groups (SARA: 0.05; control: 0.15). However, this increase in exacerbation rates was significantly lower for SARA participants (t9450=3.10, 95% CI 0.04-0.16; P=.002; Cohen d=0.06). Chronic users of inhalation medication in both study groups showed an increase in mean medication adherence over time (SARA: 6.73; control: 4.48); however, this increase was significantly higher for SARA participants (t5886=-2.74, 95% CI -3.86 to -0.84; P=.01; Cohen d=-0.07). Among new users of inhalation medication, results showed no significant difference in medication adherence between SARA and control participants in the year after implementation of SARA (t1434=-1.85, 95% CI -5.60 to 0.16; P=.06; Cohen d=-0.10). Among ICS users, no significant differences between the study groups were found over time in terms of the proportion of participants who were dispensed antimycotics (t5654=0.29, 95% CI -0.40 to 0.54; P=.76; Cohen d=0). CONCLUSIONS: This study provides preliminary evidence that the SARA eHealth intervention might have the potential to decrease exacerbation rates and improve medication adherence among patients with asthma and COPD.

Home-based telemonitoring versus hospital admission in high risk pregnancies: a qualitative study on women's experiences.

BACKGROUND: Hospital admission during pregnancy complications is considered to be an event of significant impact. Besides conventional in-clinic maternal and fetal monitoring, recent technologies enable home-based telemonitoring with self-measurements in high risk pregnancy. This study is part of a feasibility pilot to explore the usability and acceptability of telemonitoring and aims to gain insight in the experiences and preferences of high risk pregnant women concerning the novel strategy of telemonitoring, opposed to women who were hospitalized in pregnancy. METHODS: Using secured Facebook Groups, we conducted four online focus groups: two focus groups with women who were admitted during pregnancy (n = 11) and two with women who received home telemonitoring in the pilot phase (n = 11). The qualitative data were analyzed thematically. RESULTS: Four major themes emerged from both participant groups: [1] care experience, [2] emotions regarding pregnancy, [3] privacy and [4] impact on daily life. Different views were reported on all four themes, resulting in a direct comparison of experiences during hospitalization and telemonitoring. Most admitted patients reported a growing sense of boredom and anxiety during their clinical admission. Lack of privacy on ward was a great concern, as it affected their contact with hospital staff and family. This issue was not reported amongst telemonitored women. These participants still felt like a patient at times but responded that the comfort of their own home and bed was pleasant. Only a minority of telemonitored participants reported being anxious at times at home, while not having a physician or nurse nearby. Being at home resulted in less travel time for partners or family for hospital visits, which had its positive effects on family life. CONCLUSIONS: Telemonitoring of a high-risk pregnancy provides an innovative manner to monitor fetal and maternal condition from home. Compared to the experiences of hospital admission in high risk pregnancy, it allows women to be in a comforting and private environment during an anxious time in their lives. As future studies should further investigate the safety and cost effectiveness of this novel strategy, women's views on the preference of telemonitoring need to be taken into consideration.

NOACs replace VKA as preferred oral anticoagulant among new patients: a drug utilization study in 560 pharmacies in The Netherlands.

BACKGROUND: In 2012, around 400.000 patients in the Netherlands were treated with Vitamin K Antagonists (VKA) for thromboembolic diseases. Since 2011, non-VKA oral anticoagulants (NOACs) are available. NOACs do not require frequent INR monitoring which benefits patients, but also imposes a risk of reduced therapy adherence. The objective of this study is to describe uptake and patient adherence of NOACs in The Netherlands until October 2016. METHODS: Prescription data for 247.927 patients across 560 pharmacies were used to describe patient profiles, uptake of NOACs among new naive patients and switch between VKA and NOACs, and calculate therapy adherence as the Proportion of Days Covered (PDC). RESULTS: During the studied period the share of NOACs in oral anticoagulants has grown to 57% of prescriptions to new patients. More than 70% of new NOAC users were new naive patients and around 26% switched from VKA. The overall share of NOACs among starters is largest in the group of patients of 50-80 years. Calculated compliance rate for NOAC patients shows that 88% of all users are adherent with a PDC higher than 80%. CONCLUSIONS: NOAC have overtaken VKA as the major treatment prescribed to new oral anticoagulant patients, and the number of starters on VKA is decreasing. Patients are generally adherent to NOACs during the implementation phase, the period that the medication is used. Fear for inadherence by itself does not need to be a reason for not prescribing NOACs instead of VKA.

Use of oral immunosuppressive drugs in the treatment of atopic dermatitis in the Netherlands.

BACKGROUND: Although atopic dermatitis (AD) is a very common skin disease, data on the percentage of patients with really difficult-to-treat AD are scarce. From socio-economic perspective, it is important to have more insight into these numbers, as new very effective, but expensive, treatment options will be available in the near future for difficult-to-treat AD. Estimating the number of patients with AD using oral immunosuppressive drugs can give an impression of the percentage of difficult-to-treat patients in the total AD population. OBJECTIVE: To give an overview of the use of oral immunosuppressive drugs in patients with AD in the Netherlands. METHODS: Prescription data of oral immunosuppressive drugs in the Netherlands were extracted from a pharmaceutical database (NControl) containing data of 557 million prescriptions and 7.2 million patients. An algorithm, based on the WHO Anatomical Therapeutic Chemical (ATC) codes, was used to identify patients with AD. The prescription of oral immunosuppressive drugs in patients with AD between 1 January 2012 and 1 January 2017 was evaluated. RESULTS: Based on the algorithm, 65 943 patients with AD were selected. 943 patients with AD (1.4%) used cyclosporine A, methotrexate, azathioprine or mycophenolic acid. Methotrexate was most commonly used, followed by azathioprine and cyclosporine A. A switch in medication was rarely seen. In the evaluation period, a decrease in the prescription of cyclosporine A was seen, together with an increase in the prescription of methotrexate. In 31% of the patients who stopped treatment, the discontinuation took place within the first months of treatment. CONCLUSION: In this study population, 1.4% of the patients with AD used oral immunosuppressive drugs for their eczema in a 5-year period. Methotrexate was the most commonly used systemic drug in the Netherlands for the treatment of AD.

[The allocation of tasks and responsibilities in oral healthcare: basic terms]. / Toedeling van taken en verantwoordelijkheden in de mondzorg: kernbegrippen.

Oral healthcare is to an ever-larger extent delivered by a team or network. Members of such a network often seem to be unsure about the rules that govern the distribution of tasks. The Individual Healthcare Professions Act (Dutch: Wet BIG) in which this distribution is defined, makes use of very specific terms. Clarity concerning these terms is a prerequisite to be able to reflect, in a subsequent contribution, on the realisation of the prerequisites that are applicable to working in a team or network.

[Authority and division of responsibility: inventory of pressure points in dental care]. / Bevoegdheden en taakverdeling: inventarisatie van knelpunten in de mondzorg.

For patient safety and public trust in dental care it is essential that the patient can trust the person who is providing him with care. It is increasingly common for dental care to be provided by non-dentists. The regulations governing this practice are contained in the Individual Healthcare Professions Act. A recent evaluation of this legislation revealed that those affected are not generally aware of the conditions under which non-dentists are permitted to carry out tasks in dental care or that they are unsure how these requirements have to be put into practice. It is a matter of concern that this knowledge, by comparison with a previous study, has hardly increased and in some cases has actually decreased.

The plastic fly: the effect of sustained fluctuations in adult food supply on life-history traits.

Many adult traits in Drosophila melanogaster show phenotypic plasticity, and the effects of diet on traits such as lifespan and reproduction are well explored. Although plasticity in response to food is still present in older flies, it is unknown how sustained environmental variation affects life-history traits. Here, we explore how such life-long fluctuations of food supply affect weight and survival in groups of flies and affect weight, survival and reproduction in individual flies. In both experiments, we kept adults on constant high or low food and compared these to flies that experienced fluctuations of food either once or twice a week. For these 'yoyo' groups, the initial food level and the duration of the dietary variation differed during adulthood, creating four 'yoyo' fly groups. In groups of flies, survival and weight were affected by adult food. However, for individuals, survival and reproduction, but not weight, were affected by adult food, indicating that single and group housing of female flies affects life-history trajectories. Remarkably, both the manner and extent to which life-history traits varied in relation to food depended on whether flies initially experienced high or low food after eclosion. We therefore conclude that the expression of life-history traits in adult life is affected not only by adult plasticity, but also by early adult life experiences. This is an important but often overlooked factor in studies of life-history evolution and may explain variation in life-history experiments.

[Oral health related quality of life among Dutch forensic psychiatric patients]. / Mondgezondheidgerelateerde levenkwalteit bij patiënten met terbeshchikingstelling.

In order to determine the effects ofa new approach to preventive oral health treatment for forensic psychiatric patients, 3 studies were carried out using a Dutch version of the Oral Health Impact Profile-14 (OHIP-14-NL), among Dutch forensic psychiatric patients. In the first study, it was determined that the psychometric characteristics of the OHIP-14-NL were good and that attention to oral healthcare contributed positively to quality of life. The second study, which made use of an improved version of the OHIP-14-NL indicated that patients with a high level of anxiety for dental treatment and poor oral health reported a lesser quality of life. The third study showed that an effectively carried out programme of personal oral care can play an important role in the reduction of halitosis and in the improvement of quality of life. Moreover, it appeared that the retrospective version of the OHIP-14-NL was a useful method for determining the correlation between quality of life and oral health and for evaluating change therein within a relatively short period of time.

Decision-making in imminent extreme premature births: perceived shared decision-making, parental decisional conflict and decision regret.

OBJECTIVE: To describe levels of perceived shared decision making (SDM), decisional conflict (DC), and decision regret (DR) in prenatal counseling by pregnant women, partners, neonatologists, and obstetricians regarding decision-making around imminent extreme premature birth in which a decision about palliative comfort care versus early intensive care had to be made. STUDY DESIGN: Multicenter, cross-sectional study using surveys to determine perceived SDM at imminent extreme premature birth in parents and physicians, and to determine DC and DR in parents. RESULTS: In total, 73 participants from 22 prenatal counseling sessions were included (21 pregnant women, 20 partners, 14 obstetricians, 18 neonatologists). High perceived levels of SDM were found (median 82,2), and low levels of DC (median 23,4) and DR at one month (median 12, 5). CONCLUSIONS: Reported levels of self-perceived SDM in the setting of prenatal counseling in extreme prematurity were high, by both the parents and the physicians. Levels of DC and DR were low.

Robotic compounding versus manual compounding of chemotherapy: Comparing dosing accuracy and precision.

BACKGROUND: Cytostatic drugs are increasingly being prepared with a cytostatic robot, though it is not known whether the dose of the final product is more accurate after automated or manual preparation. This study is the first to compare accuracy and precision of automated preparations with manual preparations by measuring volumes and drug concentrations. METHODS: The accuracy and precision of automated and manual preparations were compared by gravimetric and concentration measurements. During ten days 80 solutions were prepared; 40 robot preparations and 40 manual preparations. With both preparation methods, 20 methotrexate (MTX) and 20 cyclophosphamide (CP) bags were compounded. We simulated normal working conditions by performing the preparations on Monday till Friday. The MTX and CP concentrations were measured with validated ultra high performance liquid chromatography (UHPLC) methods on the last preparation day. RESULTS: With UHPLC analysis, dose accuracy (mean dose error) of robotic or manual preparation of MTX were 1.70% and 0,96% respectively. With gravimetric analysis, these values were 0.50% and 1.96%. Precision (standard error) of the robotic preparation for MTX was significantly smaller than that of manual preparation (p < 0.001). Dose accuracy (mean dose error) of robotic or manual preparation of CP, with UHPLC analysis, were 6.10% and 5.20% respectively. With gravimetric analysis, these values were 0,67% and 0,18%. CONCLUSION: We conclude that both robotic and manual compounding produce accurate cytostatic products in which the mean percentage of active substance differs by less than 10% from the prescribed amount. Both preparation methods are compliant with the Dutch Medicines Act and the European Pharmacopoeia.

Neuropeptide Y Signaling in the Lateral Hypothalamus Modulates Diet Component Selection and is Dysregulated in a Model of Diet-Induced Obesity.

The preclinical multicomponent free-choice high-fat high-sucrose (fcHFHS) diet has strong validity to model diet-induced obesity (DIO) and associated maladaptive molecular changes in the central nervous system. fcHFHS-induced obese rats demonstrate increased sensitivity to intracerebroventricular infusion of the orexigenic Neuropeptide Y (NPY). The brain region-specific effects of NPY signaling on fcHFHS diet component selection are not completely understood. For example, fcHFHS-fed rats have increased intake of chow and fat following intracerebroventricular NPY infusion, whereas NPY administration in the nucleus accumbens, a key hub of the reward circuitry, specifically increases fat intake. Here, we investigated whether NPY infusion in the lateral hypothalamic area (LHA), which is crucially involved in the regulation of intake, regulates fcHFHS component selection, and if LHA NPY receptor subtypes 1 or 5 (NPYR1/5) are involved. Male Wistar rats were fed a chow or fcHFHS diet for at least seven days, and received intra-LHA vehicle or NPY infusions in a cross-over design. Diet component intake was measured two hours later. Separate experimental designs were used to test the efficacy of NPY1R- or NPY5R antagonism to prevent the orexigenic effects of intra-LHA NPY. Intra-LHA NPY increased caloric intake in chow- and fcHFHS-fed rats. This effect was mediated specifically by chow intake in fcHFHS-fed rats. The orexigenic effects of intra-LHA NPY were prevented by NPY1R and NPY5R antagonism in chow-fed rats, but only by NPY5R antagonism in fcHFHS-fed rats. Thus, NPY signaling has brain region-specific effects on fcHFHS component selection and LHA NPYR sensitivity is dysregulated during consumption of a fcHFHS diet.

The MCRA toolbox of models and data to support chemical mixture risk assessment.

A model and data toolbox is presented to assess risks from combined exposure to multiple chemicals using probabilistic methods. The Monte Carlo Risk Assessment (MCRA) toolbox, also known as the EuroMix toolbox, has more than 40 modules addressing all areas of risk assessment, and includes a data repository with data collected in the EuroMix project. This paper gives an introduction to the toolbox and illustrates its use with examples from the EuroMix project. The toolbox can be used for hazard identification, hazard characterisation, exposure assessment and risk characterisation. Examples for hazard identification are selection of substances relevant for a specific adverse outcome based on adverse outcome pathways and QSAR models. Examples for hazard characterisation are calculation of benchmark doses and relative potency factors with uncertainty from dose response data, and use of kinetic models to perform in vitro to in vivo extrapolation. Examples for exposure assessment are assessing cumulative exposure at external or internal level, where the latter option is needed when dietary and non-dietary routes have to be aggregated. Finally, risk characterisation is illustrated by calculation and display of the margin of exposure for single substances and for the cumulation, including uncertainties derived from exposure and hazard characterisation estimates.

Two novel functional mutations in the Na+,K+-ATPase alpha2-subunit ATP1A2 gene in patients with familial hemiplegic migraine and associated neurological phenotypes.

Mutations in the ATP1A2 gene, encoding the alpha2-subunit of the Na+,K+-ATPase, are associated with familial hemiplegic migraine type 2. The majority of ATP1A2 mutations were reported in patients with hemiplegic migraine without any additional neurological findings. Here, we report on two novel ATP1A2 mutations that were identified in two Portuguese probands with hemiplegic migraine and interesting additional clinical features. The proband's of family 1 (with a V362E mutation) had mood alterations, classified as a borderline personality. The proband in family 2 (with a P796S mutation) had mild mental impairment, in addition to hemiplegic migraine; more severe mental retardation was observed in his brother, who also had hemiplegic migraine and carried the same mutation. Cell-survival assays clearly showed abnormal functioning of mutant Na+,K+-ATPase, indicating that both ATP1A2 mutants are disease causing. Additionally, our results suggest a possible causal relationship of the ATP1A2 mutations with the complex clinical phenotypes observed in the probands.

Recognition and receptors in virus transmission by arthropods.

Fundamental knowledge of the molecular mechanisms underlying virus transmission by arthropods is a prerequisite for the creation of new strategies to modulate vector competence. There have been several recent advances in identifying the viral and vector determinants involved in virus recognition, attachment and retention.

Conjugated linoleic acid activates peroxisome proliferator-activated receptor alpha and beta subtypes but does not induce hepatic peroxisome proliferation in Sprague-Dawley rats.

Since conjugated linoleic acid (CLA) has structural and physiological characteristics similar to peroxisome proliferators, we hypothesized that CLA would activate peroxisome proliferator-activated receptor (PPAR). We compared the effects of dietary CLA (0.0, 0.5, 1.0 and 1.5% by weight) with a peroxisome proliferator (0.01% Wy-14,643) in female and male Sprague-Dawley (SD) rats. Dietary CLA had little effect on body weight, liver weight, and hepatic peroxisome proliferation, compared to male rats fed Wy-14,643 diet. Lipid content in livers from rats fed 1.5% CLA and Wy-14,643 diets was increased (P < 0.01) when compared to rats fed control diets regardless of gender. Hepatic acyl-CoA oxidase (ACO) mRNA levels were increased 3-fold in male rats fed 1.5% CLA diet compared to rats fed control diets while Wy-14,643 supported approximately 30-fold ACO mRNA accumulation. A similar response was observed for liver fatty acid-binding protein (L-FABP) mRNA. The effect of dietary treatments on hepatic PPAR-responsive genes in female rats was weaker than in male rats. The (9Z,11E)-CLA isomer activated PPAR alpha in transfected cells to a similar extent as Wy-14,643, whereas the furan-CLA metabolite was comparable to bezafibrate on activating PPAR beta. These data suggest that while CLA was able to activate PPARs it is not a peroxisome proliferator in SD rats.

The highly acidic C-terminal region of the yeast initiation factor subunit 2 alpha (eIF-2 alpha) contains casein kinase phosphorylation sites and is essential for maintaining normal regulation of GCN4.

Regulation of the effective activity of eukaryotic initiation factor 2 (eIF-2) in protein synthesis is known to involve phosphorylation of its alpha subunit. Two mammalian enzymes, the haem-controlled repressor (HCR) and the double-stranded RNA-activated inhibitor (dsI), phosphorylate Ser-51 of the alpha subunit, thereby inhibiting the exchange of bound nucleotides on, and thus the recycling of, eIF-2. In Saccharomyces cerevisiae, the equivalent serine seems to be phosphorylated by the GCN2 protein kinase, which is activated by amino acid starvation. However, in the present paper we show that this is not the only site of phosphorylation in yeast eIF-2 alpha. We report the preparation of recombinant yeast eIF-2 alpha from Escherichia coli and its use in in vitro phosphorylation studies. Mammalian HCR and dsI are shown to phosphorylate specifically Ser-51 of yeast eIF-2 alpha, whereas extracts from yeast cells do not. Instead, at least one of three serine residue in the acidic C-terminal region of this protein is phosphorylated by fractions of yeast possessing casein kinase activities 1 and 2. A triple Ser-->Ala mutant form of yeast eIF-2 alpha was found to be no longer phosphorylated by either of the yeast (or mammalian) casein kinase activities in vitro. Isoelectric focusing of yeast extracts confirmed that the mutated sites normally act as sites of phosphorylation in vivo. The same mutant was used to show that the three sites have no essential function under normal physiological conditions in yeast. In contrast, deletion of the 13 amino acid long C-terminal region of eIF-2 alpha, including the three phosphorylation sites, led to derepression of GCN4 in vivo. Thus removal of the short, highly acidic C-terminal region of eIF-2 alpha has the same regulatory effect on translational (re)initiation as phosphorylation of the Ser-51 residue of the wild-type protein. This result provides new insight into the role of eIF-2 alpha activity in the regulation of translational (re-) initiation.

Expression of the potato leafroll virus ORF0 induces viral-disease-like symptoms in transgenic potato plants.

The role of the open reading frame 0 (ORF0) of luteoviruses in the viral infection cycle has not been resolved, although the translation product (p28) of this ORF has been suggested to play a role in host recognition. To investigate the function of the potato leafroll luteovirus (PLRV) p28 protein, transgenic potato plants were produced containing the ORF0. In the lines in which the ORF0 transcripts could be detected by Northern (RNA) analysis, the plants displayed an altered phenotype resembling virus-infected plants. A positive correlation was observed between levels of accumulation of the transgenic transcripts and severity of the phenotypic aberrations observed. In contrast, potato plants transformed with a modified, untranslatable ORF0 sequence were phenotypically indistinguishable from wild-type control plants. These results suggest that the p28 protein is involved in viral symptom expression. Southern blot analysis showed that the transgenic plants that accumulated low levels of ORF0 transcripts detectable only by reverse transcription-polymerase chain reaction, contained methylated ORF0 DNA sequences, indicating down-regulation of the transgene provoked by the putatively unfavorable effects p28 causes in the plant cell.

Effect of deletions in the 5'-noncoding region on the translational efficiency of phosphoglycerate kinase mRNA in yeast.

Deletions of various sizes were introduced into the region of the yeast PGK gene encoding the 5'-nontranslated portion of the phosphoglycerate kinase (PGK) mRNA. The effect of these deletions on the translational efficiency of the mutant transcripts was analysed by assaying the levels of mutant PGK mRNA and PGK protein in cells transformed with the mutant genes. Quantification of transcript levels by either Northern analysis or a reverse transcription assay demonstrated that there were no significant differences in the levels of mutant PGK mRNA between the various mutants. Thus, the leader sequence does not appear to play a role in determining the relatively long half-life of yeast PGK mRNA. Analysis of PGK protein levels in the various mutants revealed no effect when the length of the leader was reduced from 45 to 27 nucleotides (nt). Protein levels dropped by about a factor 2, however, upon a further decrease to 21 nt. Additional shortening did not cause a further dramatic reduction in translational yield. Even an mRNA containing a leader of only 7 nt was still translated at about 50% of the optimal rate. Therefore, while optimal translation of a yeast mRNA requires a leader length of at least some 30 nt, shorter leaders still allow considerable translation to take place.

Differences in intermediary energy metabolism between juvenile and adult Fasciola hepatica.

A comparison of glucose catabolism by juvenile and adult liver flukes, Fasciola hepatica, showed that in the adult the cytosolic degradation of glucose via phosphoenolpyruvate carboxykinase (PEPCK) was the most important route, whereas in the freshly excysted juvenile a large part was degraded via pyruvate kinase (PK). However, it was also shown that the adult did not exclusively use the PEPCK pathway, nor did the juvenile exclusively use the PK pathway. When the juvenile was forced to anaerobic functioning it produced propionate and acetate just like the adult, but this did not imply that it switched to the pathways of the adult: the pathway via PK remained important. Malic enzyme (NADP(H)-dependent) was demonstrated to be present in the cytosol and in the mitochondria of both juveniles and adults. These enzyme activities enable the parasite to use a mixture of malate and pyruvate in any ratio as substrate for the mitochondrial production of propionate and acetate. Pyruvate dismutation was important in the anaerobically functioning juvenile, whereas in the adult malate was the major, but not the only mitochondrial substrate. The pH profiles of PK and PEPCK showed that the pathway of PEP metabolism at the PK/PEPCK branchpoint can be regulated by the pH. However, the end products of glucose breakdown were not dependent on the pH. During its development, the liver fluke will gradually be forced to anaerobic functioning. At first, the acidic end product will favour a partitioning of PEP at the PK/PEPCK branchpoint towards malate formation. Later, a lasting predominance of the PEPCK pathway occurs as PK activity almost completely disappears.(ABSTRACT TRUNCATED AT 250 WORDS)

The energy metabolism of Fasciola hepatica during its development in the final host.

Mature liver flukes, Fasciola hepatica, of different ages were isolated from the bile ducts of experimentally infected rats. Their energy metabolism was studied during aerobic incubation with [6-14C]glucose. The results showed that the aerobic potentials of the parenchymal liver flukes are not lost immediately after arrival in the bile ducts, but in a later phase. During the development of the newly excysted juvenile into the mature adult the major part of ATP production in aerobic incubations is successively contributed by three different pathways of glucose breakdown. The Krebs cycle, which is by far the main energy-yielding pathway of the juvenile fluke, is gradually replaced by aerobic acetate formation and, finally, by the anaerobic dismutation reactions of the adult liver fluke. This observed decrease in Krebs-cycle activity per mg protein is not the result of a decrease in activity per individual fluke. The Krebs-cycle activity per fluke actually increases enormously during its whole development. This indicates that the aerobic potential of adult F. hepatica is not just a remnant of earlier aerobic stages but that classical, mammalian type mitochondria are produced during the entire development of the fluke. Calculations are presented which demonstrate that the Krebs-cycle activity of the developing F. hepatica is directly proportional to the surface area of the fluke. This supports our view that Krebs-cycle activity is limited by the diffusion of oxygen and can only occur in the outer layer of the liver fluke during its entire development in the final host.