15 research outputs found

    A more reliable PCR for detection of Mycobacterium tuberculosis in clinical samples

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    Diagnostic techniques based on PCR have two major problems: false-positive reactions due to contamination with DNA fragments from previous PCRs (amplicons) and false-negative reactions caused by inhibitors that interfere with the PCR. We have improved our previously reported PCR based on the amplification of a fragment of the Mycobacterium tuberculosis complex-specific insertion element IS6110 with respect to both problems. False-positive reactions caused by amplicon contamination were prevented by the use of uracil-N-glycosylase and dUTP instead of dTTP. We selected a new set of primers outside the region spanned by the formerly used primers to avoid false-positive reactions caused by dTTP-containing amplicons still present in the laboratory. With this new primer set, 16 copies of the IS6110 insertion element, the equivalent of two bacteria, could be amplified 10(10) times in 40 cycles, resulting in a mean efficiency of 77% per cycle. To detect the presence of inhibitors of the Taq polymerase, which may cause false-negative reactions, part of each sample was spiked with M. tuberculosis DNA. The DNA purification method using guanidinium thiocyanate and diatoms effectively removed most or all inhibitors of the PCR. However, this was not suitable for blood samples, for which we developed a proteinase K treatment followed by phenol-chloroform extraction. This method permitted detection of 20 M. tuberculosis bacteria per ml of whole blood. Various laboratory procedures were introduced to reduce failure or inhibition of PCR and avoid DNA cross contamination. We have tested 218 different clinical specimens obtained from patients suspected of having tuberculosis. The samples included sputum (n=145), tissue biopsy samples (n=25), cerebrospinal fluid (n=15), blood (n=14), pleural fluid (n=9), feces, (n=7), fluid from fistulae (n=2), and pus from a wound (n=1). The results obtained by PCR were consistent with those obtained with culture, which is the "gold standard." We demonstrate that PCR is a useful technique for the rapid diagnosis of tuberculosis at various sites

    Endometrial scratching in women with one failed IVF/ICSI cycle-outcomes of a randomised controlled trial (SCRaTCH)

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    STUDY QUESTION: Does endometrial scratching in women with one failed IVF/ICSI treatment affect the chance of a live birth of the subsequent fresh IVF/ICSI cycle? SUMMARY ANSWER: In this study, 4.6% more live births were observed in the scratch group, with a likely certainty range between -0.7% and +9.9%. WHAT IS KNOWN ALREADY: Since the first suggestion that endometrial scratching might improve embryo implantation during IVF/ICSI, many clinical trials have been conducted. However, due to limitations in sample size and study quality, it remains unclear whether endometrial scratching improves IVF/ICSI outcomes. STUDY DESIGN, SIZE, DURATION: The SCRaTCH trial was a non-blinded randomised controlled trial in women with one unsuccessful IVF/ICSI cycle and assessed whether a single endometrial scratch using an endometrial biopsy catheter would lead to a higher live birth rate after the subsequent IVF/ICSI treatment compared to no scratch. The study took place in 8 academic and 24 general hospitals. Participants were randomised between January 2016 and July 2018 by a web-based randomisation programme. Secondary outcomes included cumulative 12-month ongoing pregnancy leading to live birth rate. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with one previous failed IVF/ICSI treatment and planning a second fresh IVF/ICSI treatment were eligible. In total, 933 participants out of 1065 eligibles were included (participation rate 88%). MAIN RESULTS AND THE ROLE OF CHANCE: After the fresh transfer, 4.6% more live births were observed in the scratch compared to control group (110/465 versus 88/461, respectively, risk ratio (RR) 1.24 [95% CI 0.96-1.59]). These data are consistent with a true difference of between -0.7% and +9.9% (95% CI), indicating that while the largest proportion of the 95% CI is positive, scratchin

    Residual ovarian activity during oral steroid contraception

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    Steroid drugs with contraceptive properties have been available in the clinical setting for over four decades and are still subject to improvement. Estrogens, progestins and anti-progestins have been used alone or in various combinations, regimens and routes of administration to favour the balance between efficacy and undesirable effects. One of the most important changes in this respect is the gradual lowering of steroid dosage in commercially available contraceptives. Current steroid contraceptive pills still achieve the goal of suppression of pituitary-ovarian activity, but the margins for error are minimal. In this review the available data on modes of action and the effects on suppressing pituitary-ovarian activity by different forms of oral contraception are reassessed. Although pregnancy rates provide a crude measure of contraceptive efficacy, no benchmark for pituitary-ovarian inhibition is available to test the suppressive potential of contraceptive drugs. Consequently, many studies provide incomplete and/or incomparable results. For the further study of those forms of steroid contraception that rely predominantly on suppression of ovarian activity, prevention of dominant follicles selection should be the objective

    Tussenresultaten project Informatielogistiek Natuurplanbureau

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    Cumulative pregnancy rates and selective drop-out of patients in in-vitro fertilization treatment

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    The validity of the cumulative pregnancy rate (CPR) calculated by life-table approach, obtained in a transport in-vitro fertilization (IVF) programme, was tested by the determination of possible influence of selective drop-out of patients with a poor treatment prognosis. A cohort of 1211 patients who had a first IVF cycle was followed, and the CPR after three IVF cycles was assessed. First cycles of patients who discontinued treatment after failed IVF, and of those who did not achieve a pregnancy but proceeded to a subsequent cycle, were compared for fertilization rate and for occurrence of prognosticators of poor treatment outcome: oocyte yield < or =2, and replacement of <2 embryos. The CPR after three cycles was 54.9%. No differences were found in the first and second cycles of patients who continued treatment and those who dropped out. Selective drop-out of patients with a poor treatment prognosis was not found. Therefore, although calculations of CPR using life-table analysis generally overestimate the real probability of pregnancy after successive IVF cycles, the calculated CPR after three IVF cycles gives a reliable indication of the chance of occurrence of a pregnancy for the population studied

    Compliance in a randomized controlled trial: The implementation of emotion-orientated care in psycho-geriatric facilities

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    Aim. The aim of this study was to gain insight into compliance with the introduction of a new care model [emotion-orientated care (EOC)] as part of an intervention study (RCT) in psycho-geriatric care. The success of the implementation (compliance), as well as the expectations and experiences concerning the training were studied. Methods. Observations were conducted in four intervention homes and four control homes, and care-plans of residents were also analysed to see whether the implementation had succeeded. Semi-structured interviews were conducted with four persons in each of the four intervention sites (a total of 16 interviews) to study the experiences with the training and implementation. Findings. The observations showed no clear differences between intervention and control homes with regard to the interactions between residents and professional caregivers. Analysis of the reporting systems revealed differences within, as well as between, the intervention and control homes. The content of the reports showed no differences between the intervention and control homes. The interviewees had different expectations of the EOC training, depending on their disciplinary background. The caregivers regarded the training as a confirmation of their current practice. They experienced some changes at the individual level and some of them reported that the co-operation between units had become better. At the home-level no changes were reported. Every interviewee indicated that the implementation of EOC was difficult and laborious and that there were (mainly organizational) obstacles that could hinder the implementation of the EOC training. Conclusions. Observations and the analysis of the reporting systems indicated that there was no clear difference between intervention homes and control homes as to the actual implementation of the intervention, indicating that the compliance with the new care model was not optimal. The interviews gave some insight into factors that caused lack of compliance

    Single monthly administration of the anti-progestagen Org 31710 in users of the 75 microg desogestrel progestagen-only pill: effects on pituitary-ovarian activity

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    Endocrine and ultrasound effects were studied of an intermittent (every 28 days) oral administration of 150 mg of the anti-progestagen Org 31710 during the continued daily use of 75 microg desogestrel (DSG) for progestagen-only contraception. A randomized, double-blind, placebo-controlled two-centre study was conducted in 50 healthy volunteers. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol and progesterone concentrations, and follicle number and size were studied, as well as endometrial thickness, which was assessed by transvaginal sonography at least twice weekly during a single medication cycle (cycle 3-5). Forty-eight women were evaluated (Org 31710, n = 25; placebo, n = 23). Seven ovulations were observed in the treated group versus none in the placebo group. LH concentrations were higher on days 9 and 11 and oestradiol concentrations lower on day 3 in the treated group, irrespective of whether ovulation occurred. No parameter could predict ovulation. Endometrial thickness was greater on cycle days 7-13 and 19 in the treated group. However, within the Org 31710 group, no significant differences were found in volunteers who did or did not ovulate. Observed differences may be attributed to a competitive effect of Org 31710 with progestagen-induced suppression of the pituitary-ovarian axis, altered oestradiol feedback mechanisms, and/or altered receptor availability
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