Publications by authors named "Leonard Blackwell"

Natural family planning (NFP) methods have served many generations well, and in particular, the symptothermal or symptohormonal methods. The comparison of daily mucus and temperature records for individual cycles with daily hormone measurements, which is now possible, shows that some of the assumptions underlying NFP may not be completely accurate. The various methods are inadvertently depending on an element of chance, which, of course, cannot be known by the NFP user.

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The patterns of a woman's normal ovarian activity can take many forms from childhood to menopause. These patterns lie on a continuum ranging from no ovarian activity to a fully fertile ovulatory cycle, but among the other defined patterns are cycles with anovulatory ovarian activity, including luteinized unruptured follicles (LUFs), and ovulatory cycles with deficient or short luteal phases. For any woman, these patterns can occur in any order, and one can merge into the next, without an intervening bleed, or be missed entirely.

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An enzyme-linked immunosorbent assay (ELISA) for measurement of pregnanediol-3α-glucuronide (PdG) excretion rates in urine samples diluted to 150 mL/h before analysis is described. The sensitivity of the 9 optimized standard curves was 0.093 ± 0.

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Study Question: Do the basal body temperature (BBT) shift and the cervical mucus markers for the beginning of the post-ovulatory infertile phase (POIP) of a menstrual cycle agree with the corresponding urinary pregnanediol glucuronide (PdG) threshold value?

Summary Answer: Perfect agreement between the cervical mucus markers and BBT shift and the hormonal definition of the start of post-ovulatory infertility occurred for only 7-17% of the cycles.

What Is Known Already: The PdG threshold of 7.0 µmol/24 h is an objective and accurate marker for the beginning of the POIP.

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Ligand-binding assays, such as immunoassays, are usually analysed using standard curves based on the four-parameter and five-parameter logistic models. An estimate of the uncertainty of an analyte concentration obtained from such curves is needed for confidence intervals or precision profiles. Using a numerical simulation approach, it is shown that the uncertainty of the analyte concentration estimate becomes significant at the extremes of the concentration range and that this is affected significantly by the steepness of the standard curve.

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Human milk lysozyme was conjugated with estrone glucuronide to give a monoacylated conjugate, two disubstituted isoforms, and one trisubstituted isoform in 99.4% yield. The conjugates were pure and highly inhibited (>98%) by the anti-estrone glucuronide antibody.

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Objective: To compare the results of a computer programme based on the Trigg's tracking system (TTS) identification of the basal body temperature (BBT) shift day from daily records of BBT values (TTS transition day), with the BBT shift day identified from the same records using the Sensiplan(®) symptothermal method of natural family planning.

Methods: A computer programme was written to display the daily BBT readings for 364 menstrual cycles from 51 women aged 24 to 35 years, obtained from the German Natural Family Planning (NFP) database. The TTS transition day so identified from each record was then compared with the BBT shift day estimated from the same record by the Sensiplan(®) method.

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Study Question: What are the characteristics of, and how variable are, individual normal menstrual cycle profiles of excretion rates for the urinary metabolites oestrone glucuronide (E1G) and pregnanediol glucuronide (PdG)?

Summary Answer: There is a continuum of menstrual cycle profiles that differ from standard textbook profiles but which can be understood simply in terms of growth, atresia and ovulation of ovarian follicles.

What Is Known Already: Point-of-care assays with the Ovarian Monitor pre-coated assay tubes, using urine samples diluted to a constant volume per unit time, give laboratory accurate clinical data for individual menstrual cycles. Lay operators can perform the point-of-care assay system at home to achieve reliable and reproducible results, which can be used for natural family planning.

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Fertility awareness constitutes fundamental knowledge for every woman and is an important tool for health professionals. The objective of this review is to show how fertility awareness can be useful in the assessment of a woman's health. The main techniques for detecting ovulation are explained, and then the events that characterize a normal menstrual cycle are discussed.

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Background: The UNDP/WHO/World Bank/Special Programme of Research, Development and Research Training in Human Reproduction (Geneva) set up a study to determine whether it is feasible for women to monitor their ovarian activity reliably by home testing. Daily self-monitoring of urinary hormone metabolites for menstrual cycle assessment was evaluated by comparison of results obtained with the Home Ovarian Monitor by untrained users both at home and in study centres.

Methods: Women collected daily data for urinary estrone glucuronide (E1G) and pregnanediol glucuronide (PdG) for two cycles, then the procedure was repeated in the women's local centre (in Chile, Australia or New Zealand) giving a total of 113 duplicate cycles.

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Inhibitors of kinase activities can be mechanistically diverse, genomically selective, and pathway sensitive. This potential has made these biological targets the focus of a number of drug discovery and development programs in the pharmaceutical industry. To this end, the high-throughput screening of kinase targets against diverse chemical libraries or focused compound collections is at the forefront of the drug discovery process.

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Target specificity and off-target liabilities are routinely monitored during the early phases of drug discovery for most kinase projects. Typically these criteria are evaluated using a profiling panel comprised of a diverse collection of in vitro kinase assays and relates compound structure to potency and selectivity. The success of these efforts has led to the design of similar panels for phosphatase, protease, and epigenetic targets.

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A direct enzyme linked immunosorbent assay (ELISA) system has been optimized as a reference method for the measurement of first statistically significant rises in estrone glucuronide excretion rates in human urine by analysing samples pre-diluted at the time of the collection by the women subjects to a constant urine production rate of 150 mL/h. Validation was achieved by correlation of the individual menstrual cycle profiles with the corresponding estrone glucuronide excretion rates determined by radioimmunoassay (RIA) on the same urine samples for a total of 221 samples from nine cycles. The pre-dilution procedure removed random variations due to fluctuations in the daily rate of urine excretion and minimized between sample matrix effects.

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The p38 MAP kinases are a family of serine/threonine protein kinases that play a key role in cellular pathways leading to pro-inflammatory responses. We have developed and implemented a method for rapidly identifying and optimizing potent and selective p38alpha inhibitors, which is amenable to other targets and target classes. A diverse library of druggable, purified and quantitated molecules was assembled and standardized enzymatic assays were performed in a microfluidic format that provided very accurate and precise inhibition data allowing for development of SAR directly from the primary HTS.

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Analytical equilibrium ultracentrifugation indicates that Escherichia coli MutS exists as an equilibrating mixture of dimers and tetramers. The association constant for the dimer-to-tetramer transition is 2.1 x 10(7) M-1, indicating that the protein would consist of both dimers and tetramers at physiological concentrations.

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A study was conducted to determine the accuracy and reliability of the Home Ovarian Monitor for measuring estrone glucuronide (E1G) and pregnanediol glucuronide (PdG) during ovulatory cycles as a means of monitoring ovarian activity. Approximately 60 ovulating women in three centres collected timed specimens of urine (3h or more) for a total of six cycles each. The women measured the E1G and PdG excretion per 24h in their urine specimens using the Monitor.

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Three structurally characterized estrone glucuronide-lysozyme conjugates, E1 (a 60:40 mixture acylated at K3 and K97), E3 (acylated at K33), and E5 (acylated at both K33 and K97) were isolated and purified using a combination of cation-exchange chromatography on S-sepaharose in 7M urea and hydrophobic interaction chromatography on butyl sepharose. Urea was essential to separate the conjugates into six chromatographically homogeneous fractions. In the absence of urea, complex mixtures of lysozyme and the six conjugate fractions were always encountered.

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The defined estrone glucuronide-lysozyme conjugate E3, that is acylated solely at K33, was used as a probe for the steric requirements of the active site cleft of chicken type lysozymes. When the immune complex was formed with an anti-estrone glucuronide antiserum, the rate of lysis of the E3 conjugate with the large bacterial substrate Micrococcus lysodeikticus was inhibited by over 90%. However, when the small hexamer of N-acetyl glucosamine was used as the substrate, the rate of hydrolysis by the immune complex was accelerated by 350% compared with the control rate.

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The preparation of conjugates destined for use in homogeneous enzyme immunoassays requires careful control to maximize the yield of conjugate, limit the level of substitution and obtain highly inhibitable conjugates. Furthermore, previous studies have shown that the acylation position and orientation of haptens in enzyme conjugates is important in determining the recognition and strength of binding of the hapten by anti-hapten antibodies. In this study we have prepared and purified pregnanediol glucuronide conjugates of hen egg white lysozyme by the active ester and mixed anhydride methods and compared the resulting conjugates with those obtained when conjugating with oestrone glucuronide.

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