Treatment effect of oil-based contrast is related to experienced pain at HSG: a post-hoc analysis of the randomised H2Oil study.

STUDY QUESTION: Does pain or volume of used contrast medium impact the effectiveness of oil-based contrast during hysterosalpingography (HSG)? SUMMARY ANSWER: In women who report moderate to severe pain during HSG, the use of oil-based contrast resulted in more ongoing pregnancies compared to the use of water-based contrast, whereas in women who reported mild or no pain, no difference in ongoing pregnancies was found. WHAT IS KNOWN ALREADY: We recently showed that in infertile women undergoing HSG, the use of oil-based contrast results in more ongoing pregnancies within 6 months as compared to the use of water-based contrast. However, the underlying mechanism of this fertility-enhancing effect remains unclear. STUDY DESIGN, SIZE, DURATION: We performed a post-hoc analysis of the H2Oil study, a multicentre randomised controlled trial (RCT) evaluating the therapeutic effect of oil- and water-based contrast at HSG. Here, we evaluated the impact of pain experienced at HSG and volume of used contrast media during HSG on ongoing pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHODS: In a subset of 400 participating women, pain during HSG by means of the Visual Analogue Scale (VAS) (range: 0.0-10.0 cm) was reported, while in 512 women, we registered the volume of used contrast (in millilitres). We used logistic regression analyses to assess whether pain and volume of used contrast media modified the effect of oil-based contrast on ongoing pregnancy rates. Data were analysed according to intention-to-treat principle. MAIN RESULTS AND THE ROLE OF CHANCE: In 400 women in whom pain scores were reported, the overall median pain score was 5.0 (Interquartile range (IQR) 3.0-6.8) (oil group (n = 199) 4.8 (IQR 3.0-6.4); water group (n = 201) 5.0 (IQR 3.0-6.7); P-value 0.28). There was a significant interaction between pain (VAS ≤5 versus VAS ≥6) and the primary outcome ongoing pregnancy (P-value 0.047). In women experiencing pain (VAS ≥6), HSG with oil-based contrast resulted in better 6-month ongoing pregnancy rates compared to HSG with water-based contrast (49.4% versus 29.6%; RR 1.7; 95% CI, 1.1-2.5), while in women with a pain score ≤5, 6-month ongoing pregnancy rates were not significantly different between the use of oil- (28.8%) versus water-based contrast (29.2%) (RR 0.99; 95% CI, 0.66-1.5). In the 512 women in whom we recorded contrast, median volume was 9.0 ml (IQR 5.7-15.0) in the oil group versus 8.0 ml (IQR 5.9-13.0) in the water group, respectively (P-value 0.72). Volume of used contrast was not found to modify the effect of oil-based contrast on ongoing pregnancy (P-value for interaction 0.23). LIMITATIONS, REASONS FOR CAUTION: This was a post-hoc analysis that should be considered as hypothesis generating. The RCT was restricted to infertile ovulatory women, younger than 39 years of age and with a low risk for tubal pathology. Therefore, our results should not be generalised to infertile women who do not share these features. WIDER IMPLICATIONS OF THE FINDINGS: The underlying mechanism of the fertility-enhancing effect induced by HSG with the use of oil-based contrast remains unclear. However, these findings suggest a possible mechanistic pathway, that is increasing intrauterine pressure occurring prior to dislodging pregnancy hindering debris or mucus plugs from the proximal part of otherwise normal fallopian tubes. This information might help in the search of the underlying fertility-enhancing mechanism found by using oil-based contrast during HSG. STUDY FUNDING/COMPETING INTEREST(S): The original H2Oil RCT was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The funders had no role in study design, collection, analysis and interpretation of the data. K.D. reports consultancy for Guerbet. H.V. reports consultancy fees from Ferring. C.B.L. reports speakers' fees from Ferring and research grants from Ferring, Merck and Guerbet. V.M. reports receiving travel and speakers fees as well as research grants from Guerbet. B.W.M. is supported by an NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research grants from Merck KGaA and Guerbet. The other authors do not report conflict of interests. TRIAL REGISTRATION NUMBER: The H2Oil study was registered at the Netherlands Trial Registry (NTR 3270). TRIAL REGISTRATION DATE: 1 February 2012. DATE OF FIRST PATIENT'S ENROLMENT: 3 February 2012.

The production of intrinsically labeled milk protein provides a functional tool for human nutrition research.

Oral or intravenous administration of labeled, free amino acids does not allow the direct assessment of protein digestion and absorption kinetics following dietary protein intake. Consequently, dietary protein sources with labeled amino acids incorporated within the protein are required. The aim of this study was to produce milk proteins intrinsically labeled with l-[1-(13)C]phenylalanine that would allow the assessment of protein digestion and absorption kinetics and the subsequent muscle protein synthetic response to dietary protein intake in vivo in humans. Two Holstein cows (body weight of 726 +/- 38 kg) were continuously infused with l-[1-(13)C]phenylalanine at 402 micromol/min for 44 to 48 h, during and after which plasma samples and milk were collected. After milk protein separation, casein was used in a subsequent human proof-of-principle experiment. Two healthy males (aged 61 +/- 1 yr; body mass index of 22.4 +/- 0.1 kg/m(2)) ingested 35 g of casein highly enriched with [1-(13)C] phenylalanine. Plasma samples were collected at regular intervals, and skeletal muscle biopsies were collected before and 6 h after casein ingestion. In the initial experiment, a total of 5.83 kg of l-[1-(13)C]phenylalanine-enriched milk protein (casein enrichment was 29.4 molar percent excess) was collected during stable isotope infusion in the cows. In the proof-of-principle study, ingestion of 35 g of intrinsically labeled casein resulted in peak plasma l-[1-(13)C]phenylalanine enrichments within 90 min after protein ingestion (9.75 +/- 1.47 molar percent excess). Skeletal muscle protein synthesis rates calculated over the entire 6-h period averaged 0.058 +/- 0.012%/h. The production of intrinsically labeled milk protein is feasible and provides dietary protein that can be used to investigate protein digestion and absorption and the subsequent muscle protein synthetic response in vivo in humans.

Derangement in aerobic and anaerobic energy metabolism in skeletal muscle of critically ill and recovering rats.

As part of our research into the mechanisms of protein wasting and muscle weakness during critical illness, we here investigate various aspects of energy metabolism. Intraperitoneal injection of zymosan in rats leads to an acute phase of critical illness followed by a prolonged recovery phase. Previously we observed low activities of mitochondrial enzymes, reduced protein synthesis rates and low concentrations of glutamine in skeletal muscle of zymosan-treated rats. In the present study we investigated (1) whether decreases in high energy phosphates are present in skeletal muscle of these rats and (2) whether an impairment in the glycolytic pathway or the tricarboxylic acid cycle leads to these decreases. Concentrations of creatine phosphate and ATP were decreased in zymosan-treated rats to approx. 85% of pair-fed control values respectively on day 2 and on days 4 and 6 after treatment. Concentrations of tricarboxylic acid (TCA) cycle intermediates were decreased to 80% on day 6 after zymosan treatment. Lactate/pyruvate ratio and concentrations of lactate and glycogen were normal at all sampling times. We conclude that no major changes in concentrations of high energy phosphates and in concentrations of intermediates of TCA cycle, glycolysis and glycogenolysis were present. This indicated that, although the maximal oxidative capacity (mitochondrial content) is decreased, no derangement in energy metabolism seems to be present in skeletal muscle of critically ill and recovering rats.

Do health care providers' attitudes towards back pain predict their treatment recommendations? Differential predictive validity of implicit and explicit attitude measures.

The current study aimed to measure the differential predictive value of implicit and explicit attitude measures on treatment behaviour of health care providers. Thirty-six physiotherapy students completed a measure of explicit treatment attitude (Pain Attitudes And Beliefs Scale For Physiotherapists-PABS-PT) and a measure of implicit treatment attitude (Extrinsic Affective Simon Task-EAST). Furthermore, they gave treatment recommendations for a patient simulating back pain on three video scenes. The implicit and explicit measures of attitudes were only weakly related to each other. However, both were differentially related to treatment recommendations. The implications of the differential predictive value of implicit and explicit attitude measures for treatment behaviour are discussed.

Cervical tourniquet in case of uncontrollable haemorrhage during caesarean section owing to a placenta accreta.

This case report describes a 38-year-old woman in whom a primary caesarean section for placenta previa was complicated by postpartum haemorrhage due to a placenta accreta. Despite tamponade with a Bakri balloon and placement of a B-Lynch suture, the amount of blood loss could not be effectively reduced. The blood loss was eventually minimised by the placement of a Penrose drain around the cervix as a cervical tourniquet. We think that a cervical tourniquet is an effective method of stopping haemorrhage during caesarean section, as shown in this case report, and we consider this technique to be a valuable addition to several existing methods through which fertility is preserved by preventing emergency hysterectomy.

Inhibition of adipose tissue lipolysis increases intramuscular lipid use in type 2 diabetic patients.

AIMS/HYPOTHESIS: In the present study, we investigated the consequences of adipose tissue lipolytic inhibition on skeletal muscle substrate use in type 2 diabetic patients. MATERIALS AND METHODS: We studied ten type 2 diabetic patients under the following conditions: (1) at rest; (2) during 60 min of cycling exercise at 50% of maximal workload capacity and subsequent recovery. Studies were done under normal, fasting conditions (control trial: CON) and following administration of a nicotinic acid analogue (low plasma non-esterified fatty acid trial: LFA). Continuous [U-13C]palmitate and [6,6 -2H2]glucose infusions were applied to quantify plasma NEFA and glucose oxidation rates, and to estimate intramuscular triacylglycerol (IMTG) and glycogen use. Muscle biopsies were collected before and after exercise to determine net changes in lipid and glycogen content specific to muscle fibre type. RESULTS: Following administration of the nicotinic acid analogue (Acipimox), the plasma NEFA rate of appearance was effectively reduced, resulting in lower NEFA concentrations in the LFA trial (p<0.001). Plasma NEFA oxidation rates were substantially reduced at rest, during exercise and subsequent recovery in the LFA trial. The lower plasma NEFA oxidation rates were compensated by an increase in IMTG and endogenous carbohydrate use (p<0.05). Plasma glucose disposal rates did not differ between trials. In accordance with the tracer data, a greater net decline in type I muscle fibre lipid content was observed following exercise in the LFA trial (p<0.05). CONCLUSIONS/INTERPRETATION: This study shows that plasma NEFA availability regulates IMTG use, and that adipose tissue lipolytic inhibition, in combination with exercise, could be an effective means of augmenting intramuscular lipid and glycogen use in type 2 diabetic patients in an overnight fasted state.

Carbohydrate ingestion can completely suppress endogenous glucose production during exercise.

The purposes of this study were 1) to investigate the effect of carbohydrate (CHO) ingestion on endogenous glucose production (EGP) during prolonged exercise, 2) to study whether glucose appearance in the circulation could be a limiting factor for exogenous CHO oxidation, and 3) to investigate whether large CHO feedings can reduce muscle glycogen oxidation during exercise. Six well-trained subjects exercised three times for 120 min at 50% maximum workload while ingesting water (FAST), a 4% glucose solution (LO-Glc), or a 22% glucose solution (HI-Glc). A primed continuous intravenous [6, 6-2H2]glucose infusion was given, and the ingested glucose was enriched with [U-13C]glucose. Glucose ingestion significantly elevated CHO oxidation as well as the rates of appearance (Ra) and disappearance. Ra glucose equaled Ra of glucose in gut (Ra gut) during HI-Glc, whereas EGP was completely suppressed. During LO-Glc, EGP was partially suppressed, whereas Ra gut provided most of the total glucose Ra. We conclude that 1) high rates of CHO ingestion can completely block EGP, 2) Ra gut may be a limiting factor for exogenous CHO oxidation, and 3) muscle glycogen oxidation was not reduced by large glucose feedings.

Glucose kinetics during prolonged exercise in highly trained human subjects: effect of glucose ingestion.

1. The objectives of this study were (1) to investigate whether glucose ingestion during prolonged exercise reduces whole body muscle glycogen oxidation, (2) to determine the extent to which glucose disappearing from the plasma is oxidized during exercise with and without carbohydrate ingestion and (3) to obtain an estimate of gluconeogenesis. 2. After an overnight fast, six well-trained cyclists exercised on three occasions for 120 min on a bicycle ergometer at 50 % maximum velocity of O2 uptake and ingested either water (Fast), or a 4 % glucose solution (Lo-Glu) or a 22 % glucose solution (Hi-Glu) during exercise. 3. Dual tracer infusion of [U-13C]-glucose and [6,6-2H2]-glucose was given to measure the rate of appearance (Ra) of glucose, muscle glycogen oxidation, glucose carbon recycling, metabolic clearance rate (MCR) and non-oxidative disposal of glucose. 4. Glucose ingestion markedly increased total Ra especially with Hi-Glu. After 120 min Ra and rate of disappearance (Rd) of glucose were 51-52 micromol kg-1 min-1 during Fast, 73-74 micromol kg-1 min-1 during Lo-Glu and 117-119 micromol kg-1 min-1 during Hi-Glu. The percentage of Rd oxidized was between 96 and 100 % in all trials. 5. Glycogen oxidation during exercise was not reduced by glucose ingestion. The vast majority of glucose disappearing from the plasma is oxidized and MCR increased markedly with glucose ingestion. Glucose carbon recycling was minimal suggesting that gluconeogenesis in these conditions is negligible.

Chlamydia pneumoniae and screening for tubal factor subfertility.

Chlamydia antibody testing (CAT) by micro-immunofluorescence (MIF) tests has been introduced into the fertility work-up as a screening test for tubal factor subfertility. In this study the role of C. pneumoniae antibodies, as a cause for false positive CAT results due to cross-reactivity with C. trachomatis antibodies in the MIF test, has been evaluated. In 240 subfertile women serological data were compared to laparoscopy findings. The prevalence of C. pneumoniae antibodies using enzyme-linked immunosorbent assay (ELISA) was 75% and did not differ between patients with and without tubal pathology. C. pneumoniae antibodies were found in 87% of women with a positive MIF test (> or =32), and in 66% with a negative MIF test (P < 0.0005). Using ELISA instead of MIF for the detection of C. trachomatis antibodies, C. pneumoniae antibodies were found in 87% of C. trachomatis positive women, and in 69% of C. trachomatis negative women (P < 0.0005). Patients without tubal factor subfertility but a positive MIF test showed C. pneumoniae antibodies more frequently than patients without tubal factor subfertility and a negative MIF test. Therefore it was suggested that C. pneumoniae antibodies may be the cause of false positive CAT results. Remarkably, tubal pathology was more common in patients who had antibodies to both C. trachomatis and C. pneumoniae.

Performance of five serological chlamydia antibody tests in subfertile women.

BACKGROUND: Micro-immunofluorescence (MIF) is widely used for chlamydia antibody testing (CAT). Recently a species-specific MIF and three enzyme-linked immunosorbent assay (ELISA) tests have been introduced. We compared five commercially available CAT tests, using laparoscopy as a reference, and evaluated whether combinations of tests could improve the predictive value of CAT. METHODS: In a consecutive cohort of 315 subfertile women, results of the five CAT tests were correlated to findings at laparoscopy. Likelihood and odds ratios (OR) were calculated for single tests and for combinations of tests. RESULTS: Of the tests evaluated, MIF Labsystems had the best diagnostic performance (OR 15.7), while pELISA Medac (OR 8.2) was the best of the three ELISA tests. Stepwise logistic regression analysis showed that performance of MIF Labsystems could not be improved by adding a second test. Significant cross-reactivity with C. pneumoniae antibodies was found in all tests evaluated, except in pELISA Medac. CONCLUSIONS: In screening for tubal factor subfertility, MIF Labsystems was superior to the ELISA tests evaluated, and combining two CAT tests did not improve its predictive value. Economic analysis will show whether serial testing by pELISA Medac, and retesting positive samples by MIF Labsystems, is most cost-effective. In CAT, cross-reactivity with C. pneumoniae antibodies is still a major concern.

Mast cell-mediated induction of ICAM-1, VCAM-1 and E-selectin in endothelial cells in vitro: constitutive release of inducing mediators but no effect of degranulation.

Mast cell (MC)-mediated induction of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and of E-selectin was studied in cultures of rat heart endothelial cells (EC) and human umbilical vein EC (HUVEC) respectively. MC induced VCAM-1 and E-selectin, but hardly any ICAM-1 in EC. Induction was not dependent on MC degranulation, but seemed to be provoked by constitutively released substances, other than histamine, from MC. Co-incubation of MC and EC, allowing for direct contact between the two cell types, was more potent in induction than MC co-incubated separately from EC using a permeable membrane. MC were less potent in induction than exogenous added cytokines or LPS. Induction of cell adhesion molecules in rat heart EC was MC-specific, since EC incubations with either rat cardiomyocytes or heart fibroblasts had no effect. The data show that rat MC, independent of degranulation, secrete mediators relevant for the induction of a specific set of EC adhesion molecules in vitro. This suggests a (supportive) role for MC in cell-adhesion molecule induction in the endothelium in settings of early or mild inflammation. The results are discussed in the context of inflammatory processes in the heart in vivo.

Validation of the [1,2-13C]acetate recovery factor for correction of [U-13C]palmitate oxidation rates in humans.

1. The validity of estimations of plasma fatty acid oxidation using tracers has often been questioned. The appearance of isotopic markers in breath CO2 is delayed and incomplete. Recently suggestions have been made that substantial amounts of tracer are incorporated into products of the tricarboxylic acid cycle (e.g. glucose, glutamine and glutamate) and that an acetate correction factor can be used to correct for tracer fixation. In the present study we investigated whether the appearance of 13CO2 during a separate infusion of [1,2-13C]acetate could be used for correction of [U-13C]palmitate oxidation rates in studies lasting <2 h and we quantified the appearance of tracer in the glutamine, glutamate and glucose pools of the body. 2. An infusion of either [1,2-13C]acetate (0.104 micromol min-1 kg-1) or [U-13C]palmitate (0.013 micromol min-1 kg-1) was given to eight male subjects and continued for 2 h at rest. In six subjects the infusion of [1,2-13C]acetate was repeated to determine reproducibility of the acetate recovery. 3. Fractional recovery in breath from [1,2-13C]acetate gradually increased during the infusion period at rest from 14.1 +/- 0.6% at 60 min to 26.5 +/- 0.5% at 120 min after the start of the infusion. Intersubject coefficient of variance was 8.3 +/- 0.6% and intrasubject coefficient of variance of the acetate recovery tests was 4.0 +/- 1.5%. After 2 h of [1,2-13C]acetate infusion, 12.4 +/- 0.8 and 10.3 +/- 0.9% of infused 13C was incorporated in the glutamine and glutamate pools, respectively. 4. In conclusion, the [1,2-13C]acetate recovery factor can be used for correcting the rate of [U-13C]palmitate oxidation in infusing studies of 2 h in resting conditions. Failure to use this recovery factor leads to a substantial underestimation of the rate of plasma free fatty acid oxidation. The extent of label fixation could largely be explained by accumulation of tracer carbon in glutamine and glutamate, and the accumulation in glucose is negligible.