Predictive limitations of spatial interaction models: a non-Gaussian analysis

We present a method to compare spatial interaction models against data based on well known statistical measures that are appropriate for such models and data. We illustrate our approach using a widely used example: commuting data, specifically from the US Census 2000. We find that the radiation model performs significantly worse than an appropriately chosen simple gravity model. Various conclusions are made regarding the development and use of spatial interaction models, including: that spatial interaction models fit badly to data in an absolute sense, that therefore the risk of over-fitting is small and adding additional fitted parameters improves the predictive power of models, and that appropriate choices of input data can improve model fit.

Abstract P4-15-04: A longitudinal cohort study to identify risk factors for the development of invasive cancer in unresected DCIS

Background: The variable natural history of ductal carcinoma in situ (DCIS) remains poorly understood. Randomized trials of active surveillance versus guideline concordant care are currently underway: the Comparison of Operative to Monitoring and Endocrine Therapy (COMET) trial in the US, LOw Risk dcIS (LORIS) trial in the UK and Low Risk Dcis (LORD) in Europe. Given this context, we examined the outcomes of a contemporary group of women with DCIS who did not undergo initial surgical resection.

Methods: A longitudinal cohort of women diagnosed with DCIS on needle biopsy who did not undergo initial surgical excision for ≥1 year were identified through the Cancer Registry with case note and death certificate review for subsequent outcomes.

Results: Eighty-nine eligible women with DCIS alone diagnosed on needle biopsy (most with 14-gauge core needle biopsy) between 1998 and 2010 were identified. The mean age at diagnosis was 72 years (range 44-94 years) with mean follow-up (diagnosis to death, invasive disease or last review) of 62 months (range 12-180 months). Twenty-nine women (33%) developed histologically proven invasive breast cancer, 28 at the site of the initial DCIS biopsy, after a mean interval of 54 months (range 12-144 months): 14/29 (48%) women originally had high grade DCIS, 10/31 (32%) intermediate grade and 3/17 (18%) low grade DCIS (initial grade not known in 12). Time to detect a diagnosis of invasive breast cancer was associated with initial grade of DCIS (p=0.0016, log-rank test): after mean intervals of 41 months (high grade), 69 months (intermediate grade) and 78 months (low grade) respectively. Younger age was associated with development of invasive disease (p<0.003, Mann-Whitney U-Test). High grade (grade 3) invasive breast cancer exclusively occurred in women with a prior diagnosis of high grade DCIS. Invasion was more frequent in lesions with calcification as the predominant feature than those without (23/50 v. 5/25; p<0.05, Fisher exact test). Forty-four women were prescribed endocrine therapy, use of which was associated with a lower rate of invasive breast cancer (p<0.05). Ultimately 18 women underwent surgery, 17 for invasive cancer. The mean interval from DCIS diagnosis to death was 76 months for those who developed invasive cancer; 48/89 women died, 12 had a certified cause of death as breast cancer.

Conclusion: High grade DCIS, mammographic microcalcification and lack of endocrine therapy were associated with progression to invasion. The findings suggest surgical excision of high grade DCIS should continue but provides support that women with DCIS features which include low grade should be considered for the COMET, LORIS or LORD active surveillance trials.

Citation Format: Maxwell AJ, Clements K, Hilton B, Dodwell DJ, Evans A, Olive K, Pinder SE, Thomas J, Matthew WG, Thompson AM. A longitudinal cohort study to identify risk factors for the development of invasive cancer in unresected DCIS [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-04.

Recombinant human luteinizing hormone: a partial physicochemical, biological and immunological characterization

The aim of this study was to partially characterize the glycoform composition of a recombinant human luteinizing hormone preparation (rhLH; Serono), an early version of the material (LHadi) which is currently being assessed for clinical application. Specifically, the charge (pl) and internal carbohydrate complexity of this rhLH was examined and compared with that of an alternative commercially available form of recombinant LH (Crystal Chem) and a pituitary International Reference Preparation (IRP). All preparations were separated by charge by chromatofocusing them on a pH gradient (7-4) using a 4 ml mono-P column is conjunction with a fast performance liquid chromatography system and by complexity of the oligosaccharide structures using concanavalin A (con-A) lectin affinity chromatography. LH in both the unfractionated and fractionated material was assessed by immunoradiometric assay (IRMA, I-LH) and by the in-vitro Leydig cell bioassay (B-LH). Both assays were calibrated against IRP 80/552. The in-vitro biopotency of the preparations was 18187 (Serono rhLH), 12063 (Crystal Chem rhLH) and 6658 (80/552) IU/mg; biological:immunological ratios were 1.14 (80/552), 1.90 (Crystal Chem rhLH) and 1.99 (Serono rhLH). However, similar qualitative data were obtained by both bioassay and immunoradiometric assay following fractionation, with the median pl of the bioactive LH in the preparations being 5.5 (24% > pH 6), 5.52 (18% > pH 6) and 4.97 (0% > pH 6) for the Serono, Crystal Chem and pituitary preparations respectively. Further all three contain < 1% of the complex carbohydrate structures and between 36-44% and 56-63% of the intermediate and simple forms of bioactive LH. In conclusion, the Serono recombinant LH preparation has a higher in-vitro bioactivity and is more basic than the other two preparations although the complexity of its carbohydrate moities appears to be similar.

Oestradiol and immunoreactive inhibin-like secretory patterns following controlled ovarian hyperstimulation with urinary (Metrodin) or recombinant follicle stimulating hormone (Puregon)

Inhibin (and its alpha-subunit) may be of particular value as a marker for follicular development in in-vitro fertilization (IVF) in comparison with the classic follicle stimulating hormone (FSH)-dependent marker oestradiol in patients following pituitary desensitization and treatment with recombinant FSH (rFSH). This preparation lacks luteinizing hormone (LH), which is essential for thecal cell androgen secretion and thus oestradiol production. Our study has assessed oestradiol and immunoreactive inhibin-like secretion following ovarian stimulation with rFSH or a purified urinary FSH preparation (Metrodin) (uFSH). A randomized, assessor-blind study was initiated using patients receiving a single treatment cycle of IVF (using fresh embryos) following pituitary desensitization with intranasal buserelin (500 microg daily) and the i.m. injection of either rFSH (n = 38) or uFSH (n = 17). Ovarian ultrasound examinations were performed and bloods (10 ml) collected prior to FSH treatment and every 1-2 days until ovulation induction with human chorionic gonadotrophin. LH and FSH concentrations were measured by an immunoradiometric assay, and inhibin-like immunoreactivity by a radioimmunoassay and an enzyme-linked immunosorbent assay, both with alpha-subunit specificity. Oestradiol concentration was measured with a coated tube radioimmunoassay. Following desensitization, basal LH, FSH and oestradiol concentrations were measured, as was that of immunoreactive inhibin. Following treatment with either rFSH or uFSH, LH concentrations remained low while FSH concentrations rose to a plateau of 5.6-6.7 IU/l in both groups. In contrast, the concentration of oestradiol was higher (P < 0.05) with rFSH than with uFSH in the last four days of treatment, a pattern that was repeated for inhibin-like immunoreactivity. The change in oestradiol and inhibin concentrations during treatment was approximately 2-fold higher with rFSH. The total number of follicles obtained with rFSH was similar to that with uFSH. However, the number of follicles with a diameter of >/= 15 mm was higher the rFSH group, and there was a concomitant increase in the number of oocytes recovered. Oestradiol concentration and inhibin-like immunoreactivity (determined by either method) were associated with total follicle number and number of follicles >/= 15 mm in diameter, as well as with each other (P < 0.001). When ovarian hormone output was normalized per follicle produced, oestradiol output was higher for rFSH than for uFSH P = 0.04). Inhibin output was clearly higher using rFSH than uFSH. There were seven pregnancies (one miscarriage) with rFSH and two with uFSH. Despite similar concentrations od FSH in patients, rFSH (Puregon) appears to be more potent in vitro in terms of follicular number, ovarian hormone secretion (both concentration and output/follicle) and oocyte recovery. In both groups, LH concentrations of approximately 1.3 IU/l were sufficient to support oestradiol secretion similar to that normally found in IVF programmes using human menopausal gonadotrophin preparations containing large amounts of LH. Despite known problems of specificity with the assays od inhibin, its measurement was of similar value to oestradiol as a marker of follicular development.

In-vitro biopotency and glycoform distribution of recombinant human follicle stimulating hormone (Org 32489), Metrodin and Metrodin-HP

In this study the in-vitro biopotency and glycoform distribution of human recombinant follicle stimulating hormone (FSH, Org 32489) has been assessed. The biopotency of recombinant FSH was studied using animal (rat Sertoli) and human (granulosa-lutein) cell models. Recombinant FSH, as measured in the rat Sertoli cell assay, was more potent than the urinary preparations Metrodin, Metrodin-HP and IS 70/45 with half maximal stimulation (ED50; mean +/- SEM, n > 3) occurring at 2.2 +/- 0.5 IU/I (recombinant FSH), 4.7 +/- 1.1 IU/I (Metrodin), 13.2 +/- 0.7 IU/I (Metrodin-HP) and 6.4 +/- 0.3 IU/I (IS 70/45); the pituitary preparation IRP 83/575 had an ED50 of 10.4 +/- 0.1 IU/I. Using human granulosa-lutein cells, cultured for up to 4 days in the absence of exogenous steroid precursors, recombinant FSH was either without effect (three out of five patients) or inhibited both oestradiol and progesterone secretion. FSH (83/575) was without effect on oestradiol with preparations from any of the patients but slightly stimulated (134 +/- 8%; mean +/- SEM, P < 0.05) progesterone production at the highest dose (80 IU/I). The distribution of FSH isoforms, assessed by polyclonal radioimmunoassay, following chromatofocusing over the ranges pH < 3.5 and pH 3.5-7.0 respectively was recombinant FSH, 12.4 and 87.6%; Metrodin, 19.8 and 80.2%; Metrodin-HP, 50.2 and 49.8%; IS 70/45, 15.0 and 85.0%; IS 83/575, 70.9 and 29.1%. All glycoforms were pI < 7.0 for the five preparations.(ABSTRACT TRUNCATED AT 250 WORDS)

The benefits of business process mapping

We believe that you should view an organization as an integrated organism. Treating parts of this organism without first understanding the whole and how the parts interrelate leads to suboptimal solutions. "Reinventing" an organization requires fresh, objective, new insights. We believe Business Process Analysis and its associated "mapping" is a superior approach to corporate improvements because of: 1. Its emphasis on business processes. 2. Its organization-wide approach. 3. The discipline of requiring process definitions and building the matrices (mapping) required. 4. The involvement of all decision makers. 5. Its usefulness in so many vital areas of management. We know that, given proper top management support and a proper implementation, valid and acceptable improvements will result.

Insulin-like growth factor-I stimulated growth and progesterone production by granulosa-lutein cells. Lack of interaction with physiological concentrations of luteinizing hormone and follicle stimulating hormone

This study examined the effect of physiological concentrations of insulin-like growth factor-I (IGF-I), follicle stimulating hormone (FSH) and luteinizing hormone (LH) alone and in combination on growth and progesterone production by human granulosa-lutein cells. Granulosa-lutein cells were obtained from patients (n > 5) undergoing in-vitro fertilization (IVF) or gamete intra-Fallopian transfer (GIFT) treatment. Cells were cultured for 2 and 4 days in the presence of physiological concentrations of human LH (code 68/40, 5 IU/l), FSH (code 83/575, 20 IU/l), or IGF-I (30 ng/ml) alone and in combination. Medium was changed every 2 days. No change in cell number (relative to each patient's own control) was observed after treatment with FSH or LH alone or in combination at any time. IGF-I alone produced a 117 +/- 8% and 176 +/- 15% (mean +/- SEM, n = 5) increase in cell number after 2 and 4 days respectively. This increase was unaffected by the addition of LH or FSH at any time. Basal progesterone secretion was variable (1633, 975-2409 nmol/l, median and interquartile range, day 2) and decreased with time in culture (564, 375-1089 nmol/l, day 4). After 2 days culture progesterone output increased by 116 +/- 5% of control in response to LH and 153 +/- 13% (mean +/- SEM, n = 5) of control in response to IGF-I. After 4 days, LH and IGF-I stimulated progesterone levels by 279 +/- 52% and 264 +/- 37% (mean +/- SEM, n = 5) respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Business process analysis. Part 2

We are addressing in this three part series, the challenge of making lasting, logical and linked improvements in your organization, aided by fresh, comprehensive and almost certainly unique, new view(s) of your organizational system. Preparing your organization for this type of needed "reinvention" of the organizational system can be better assured if some, preferably all, of the conditions listed in Figure 1 are present. These were introduced and discussed in last month's article. The last item in Figure 1 refers to a "Business Process Map" of the organization. Chances are that you have never encountered this term and only have a vague idea of what is meant by it. Explaining the basis of this evaluative approach is the purpose for this article. Next month, we will show ho useful this insight can be in many strategic decision areas of your business.

Is your organization ready for change?

This article is part of a series written for those who wish to bring about broad, permanent improvements in their organization; those who are "change managers." The subject is change management: Why is change necessary? How to approach it from an overall systems point of view? What are the most important organizational preconditions for any real change to occur? Eight key conditions you should have as a platform for change are listed in this first article. One of these is what Mr. Hilton calls "Business Process Analysis (BPA)." In the second article, this exciting methodology will be discussed. For those of you who prefer the "how to do it" over the theory, this is for you. Then, in November's issue, the benefits of BPA will be shown to have incredible leverage for the change manager and serve as a basis for sound Management Information System Planning, Corporate Restructuring, Process Reengineering, Budgeting, Departmental Productivity Improvement Programs, and Pay-for-Performance Programs. If you fancy yourself a change manager, from CEO to Junior Analyst, you will not want to miss reading this series.

Three-dimensional structure and antigenicity of transmembrane-protein peptides of the human immunodeficiency virus type 1. Effects of a neutralization-escape substitution

A point mutation (Ala-589 to Thr) in the transmembrane protein of the human immunodeficiency virus type 1 (HIV-1) has been shown to decrease the sensitivity of the virus to the neutralizing effect of human HIV-1 specific antibodies [(1990) J. Virol. 64, 3240-3248]. Here 17-residue peptides with the parental and mutant sequences were compared: the parental peptide bound antibodies of sera from HIV-1 infected persons more frequently and with higher affinity than the mutant peptide. However, according to circular dichroism (CD), NMR spectroscopy and molecular modelling the peptides have indistinguishable backbone conformations under a variety of experimental conditions. These techniques showed for both peptides that no ordered helix was present in water solution. However, for both peptides in alcohol-water solutions approximately 60% alpha-helix could be induced. The three-dimensional structures of these peptides provide a basis for understanding how this mutation in the transmembrane protein may affect the interaction with both the outer envelope glycoprotein and with antibodies.