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Biomedical subjects

A M Simons

Publications and source records attributed to A M Simons.

At least 19 recordsLinked to original sources
PubMed2004

The repeatability of the 24-hour pad test.

A prospective observational study was conducted in a tertiary urogynaecology unit in women with the primary symptom of urinary incontinence to assess the repeatability of the 24-hour pad test. One hundred and eight women undertook seven 24-hour pad tests over 7 consecutive days together with 7 simultaneous fluid and activity charts. The results were analysed collectively and according to urodynamic subsets. Repeatability was assessed by repeated measures analysis of variance and univariate analysis of variance for each urodynamic diagnosis group (USI, mixed and no USI). Variation between pad test weights over the 7 days was low, supporting good repeatability. The number of days of pad testing required to approximate the 7-day average was 3 days. However, a single 24-hour pad test correlated highly with the 7-day average (r=0.881) and was considered sufficient to gauge leakage severity.

Aged↗
PubMed2003

Suboptimal timing of reproduction in Lobelia inflata may be a conservative bet-hedging strategy.

Age and size at reproduction are important components of fitness, and are variable both within and among angiosperm species. The fitness consequences of such life-history variation are most readily studied in organisms that reproduce only once in their lifetime. The timing of the onset of reproduction (bolting) in the monocarpic perennial, Lobelia inflata, occurs over a range of dates within a season, and may be postponed to a later year. Empirical relationships among life-history traits, derived from over 950 wild-growing and experimentally manipulated plants in the field, are used to model an optimal changing size threshold (norm of reaction) for bolting over the growing season. Comparisons are made between observed and expected norms of reaction governing bolting. An apparently suboptimal bolting schedule that precludes bolting beyond an early (conservative) date is observed, and is found to be qualitatively consistent with conservative bet hedging under unpredictable season lengths. On this basis we propose the schedule of bolting as a plausible example of a conservative bet-hedging strategy. The results underscore the critical need for long-term studies of fluctuating selection to distinguish suboptimality from bet hedging.

Adaptation, Biological↗
PubMed2001

Use of the Dowell Bryant Incontinence Cost Index as a post-treatment outcome measure after non-surgical therapy.

The aim of this study was to use the previously validated Dowell Bryant Incontinence Cost Index (DBICI) as a post-treatment outcome measure after non-surgical therapy and to determine whether the magnitude of reduced leakage would correlate with the magnitude of reduced personal cost. A simple urethral occlusive device (Femassist) was employed in 57 women with stress, urge, or mixed incontinence for 1 month. The DBICI was administered at baseline and after device use, along with a visual analogue scale (VAS) for severity of incontinence impact, a 3-day frequency volume chart (FVC) that documented leaks per 24 hours and pad usage, a 1-hour ICS pad test at standard volume, and two disease-specific quality of life measures (Urogenital Distress Inventory [UDI] and Incontinence Impact Questionnaire [IIQ]). The severity of leakage was significantly reduced on all parameters, and the median personal costs of incontinence fell from AU$6.52 per week (IQR 1.50-10.59) to a median of AU$ 1.57 per week (IQR 0-4.89). A significant correlation (Kendall's rank, tau) was observed between reduction in personal costs and reduction in VAS (tau = 0.24, P= 0.01), leaks/day (tau = 0.20, P = 0.03), pad test loss (tau = 0.29, P = 0.002), and quality of life scores (UDI, tau = 0.23, P = 0.01; IIQ, tau = 0.26, P = 0.005). The personal costs subset of the DBICI appears to be a useful outcome measure for urinary incontinence research and could be widely employed to assess the impact of continence treatments on the patient's economic burden.

Aged↗
PubMed2001

Inadequate repeatability of the one-hour pad test: the need for a new incontinence outcome measure.

OBJECTIVE: To assess the reproducibility of two one-hour pad tests performed within one week using serial ultrasound scanning to obtain identical bladder volumes, and to measure the effect of patient anxiety upon test reproducibility. DESIGN: Prospective observational study. SETTING: Tertiary urogynaecological unit. SAMPLE: Fifty-six incontinent women undergoing 112 pad tests. METHOD: Two one-hour pad tests were performed with natural diuresis one week apart prior to treatment. At the second test, serial ultrasound scans were performed until bladder volume reached that of the first test, followed by identical provocation. MAIN OUTCOME MEASURES: One-hour pad loss, bladder volumes (Vol1, Vol2), anxiety VAS questionnaire. RESULTS: Despite serial scanning, bladder volumes differed significantly. Median volume before second pad test was 541 mL, compared with 433 mls before first test (P < 0.001). The second pad test was also significantly larger than first (median 16g vs 4g, P = 0.017), and 13/56 (23%) women were dry on the first test but incontinent on the second. In 26 women (46%) both bladder volumes were similar, but the second pad loss was still significantly greater (median 14g vs 4g, P = 0.037). The mean difference between tests was 10g and the limits of agreement were wide (ranging from -44 to +66 g difference for the test result). Women were more anxious about leaking during the first test (Median VAS during the first test was 2.8cm, compared with 0.6cm during the second test, P = 0.008). 42.5% found the second test to be more typical. CONCLUSION: In women with similar bladder volumes, the test-retest reliability of the one-hour pad test was judged to be clinically inadequate, as the first and second pad test could differ by -44 to +66g. Lower anxiety levels at the second test may account for this finding. The one-hour pad test is a useful baseline measure of incontinence, but the poor repeatability suggests that is not an optimal measure of post-treatment change.

Anxiety↗
PubMed2000

Plasticity and the genetics of reproductive behaviour in the monocarpic perennial, Lobelia inflata (Indian tobacco).

The timing of reproduction is an important life-history variable, especially for organisms that die following a single reproductive episode, such as the monocarp Lobelia inflata. The propensity to initiate flowering (to bolt) under a given set of conditions is expected to be shaped by natural selection acting on the norms of reaction for bolting behaviour over, for example, changing photoperiods. We study the genetic basis of bolting and of the plasticity of bolting using three continuously changing photoperiod regimes over two generations in a growth chamber experiment. Multiple genotypes from three populations are tested under three different photoperiod treatments mimicking early, mid, and late 'summer' during both generations. The frequency of bolting ranges from 88% under long days to 1% under short days. The overall heritability (h2) of bolting is found to be high, and increases later in the flowering season. Genetic variance for bolting is explained by genetic variance for threshold size itself, rather than for capacity to attain a fixed threshold size: genotypes that bolt most readily tend to be those that bolt at a smaller rosette size. No significant heritability of the plasticity of bolting behaviour is detected. Similarly to within populations, variation at the among-population level exists for bolting behaviour. There is no evidence for genetic population differentiation with respect to plasticity for bolting: although plasticity differs among populations within a generation, this population effect is not consistent between the two generations of the experiment.

Asteraceae↗
PubMed2000

Variation in seed traits of Lobelia inflata (Campanulaceae): sources and fitness consequences.

Seed germination constitutes an important event in the life cycle of plants. Two related seed traits affect fitness: seed size and the timing of seed germination. In three sets of experiments, we (1) partition the sources of seed-size variance in Lobelia inflata into components attributable to fruit size, relative fruit position, and parental identity; (2) examine the influence of pregermination conditions and seed size on time to germination; and (3) assess the fitness consequences of seed size and germination timing under seminatural, harsh conditions. Seed-size variance is attributable to both parental identity and fruit position within an individual. Distal fruits produce larger but fewer seeds. No significant correlation exists between fruit size and seed size, but a trade-off is found between the number and size of seeds contained in a fruit after correcting for fruit size. The timing of germination is influenced by seed size, light conditions before winter, and winter duration. Germination timing influences survival, and despite small seed size in this species (2 × 10 g/seed), seed size has a persistent and significant association with both final plant size and the probability of survival to autumn.

Journal Article↗
PubMed1999

Calculating the direct costs of urinary incontinence: a new test instrument.

OBJECTIVES: To develop a universally applicable test instrument to measure the total direct costs of urinary incontinence, including personal costs and treatment costs, i.e. the Dowell-Bryant Incontinence Cost Index (DBICI), and to study the construct validity and test-retest reliability of the instrument. PATIENTS AND METHODS: In a prospective observational study, 100 consecutive community-dwelling ambulatory women who presented with stress, urge or mixed incontinence were asked to complete the DBICI questionnaire on two occasions, 7 days apart, before any treatment. The construct validity of the DBICI was ascertained by correlation with other standard measures of urinary incontinence severity; (i) a visual analogue scale (VAS) to assess the impact of leakage upon lifestyle; (ii) frequency-volume charts (voids/24 h, leaks/week); (iii) urine loss during a standard 1 h pad test; and (iv) two disease-specific quality of life questionnaires. The test-retest reliability was measured by comparing the two test results and the construct validity of the individual subsets (personal and treatment) of the DBICI similarly assessed. RESULTS: Ninety-seven women completed the baseline assessment and 84 completed the re-test. The median (interquartile range) total direct incontinence cost (in Au$) was 12. 89 (5.26-22.67) per week, which comprised the median personal costs of 5.61 (1.68-10.36) and the median treatment costs of 4.96 (1.22-13. 37). The total direct incontinence cost was significantly correlated with the severity of urinary leakage on a 1 h pad test (Kendall's rank correlation, P=0.01), with the VAS impact score (P<0.001) and with the number of leaks/week (P=0.005). The correlation between the personal cost subset and other quantitative measures was also highly significant. Test-retest analysis of the personal costs subset revealed that this subset was robust and satisfied the statistical criteria of repeatability. CONCLUSIONS: The DBICI gives a detailed measure of the direct economic costs of urinary incontinence in ambulatory home-dwelling women, with the construct validity confirmed by the significant correlation with other quantitative measures of incontinence. By substituting local prices into the test format, the index should be useful in other countries. In the current climate of economic rationalization, such an index should be a part of future urinary incontinence research.

Adult↗
PubMed1998

Strand exchange protein 1 (Sep1) from Saccharomyces cerevisiae does not promote branch migration in vitro.

It has been shown in vitro that Saccharomyces cerevisiae strand exchange protein 1 (Sep1) promotes the transfer of one strand of a linear duplex DNA to a homologous single-stranded DNA circle. Sep1 also has an exonuclease active on DNA and RNA. By using exonuclease III-treated linear duplex DNA with various lengths of single-stranded tail as well as Ca2+ to inhibit the exonuclease activity of Sep1, we show that the processivity of exonuclease activity of Sep1 is greater than previously reported. The results in this work also demonstrate that the joint molecule between the linear duplex and single-stranded circle observed from the Sep1-promoted strand transfer reaction is just the pairing between the long single-stranded tail of the linear duplex DNA (generated by the exonuclease activity of Sep1) and the single-stranded circular DNA. When a synthetic Holliday junction was used as substrate, branch migration facilitated by Sep1 could not be detected. Finally, using electron microscopy no alpha-structure, a joint molecule with displaced single-stranded DNA tail that indicates branch migration could be observed. The results imply that Sep1 cannot promote branch migration in vitro. Further investigation is needed to determine the role of Sep1 in recombination in vivo.

DNA, Circular↗
PubMed1998

Phylogenetic relationships of the western North American phoxinins (Actinopterygii: Cyprinidae) as inferred from mitochondrial 12S and 16S ribosomal RNA sequences.

Parsimony analysis of the mitochondrial 12S and 16S rRNA sequences of North American phoxinin taxa indicated the existence of three major clades, the Western Clade, the Creek Chub Clade, and the Open Posterior Myodome Clade. The monophyletic Western Clade identified in this paper contained fewer taxa than that identified by previous authors. This clade contained species restricted to drainages west of the Continental Divide, such as Gila, Acrocheilus, Relictus, Eremichthys, Siphateles, Ptychocheilus, Lavinia, and Orthodon, and the wide-ranging genus Phoxinus found in eastern North America and Eurasia. Within this Western Clade Phoxinus was the basal sister group. Gila was recognized as a monophyletic group exclusive of Siphateles and Snyderichthys, clades traditionally recognized as subgenera of Gila. The genus Gila was most closely related to the genus Acrocheilus and together these formed the sister group to the genus Relictus. These relationships were supported independent of weighting schemes used in analyses. Identification of Phoxinus as the basal sister taxon of the Western clade implies that other major clades of North American Phoxinins likely have Asian or European relatives.

Animals↗
PubMed1997

Repair of a fractured implant-supported mesiostructure bar.

Osseointegrated implants are often used for mandibular denture retention. Although clinical success rates are high, complications can occur. A specific clinically relevant example of a fractured bar is presented along with a procedure for its repair. This procedure allows the repair to be done in a timely and cost-efficient manner.

Dental Casting Technique↗
PubMed1996

The rationale for soft-tissue grafting and vestibuloplasty in association with endosseous implants: a literature review.

Significant soft-tissue complications have been reported around endosseous implant permucosal abutments. Peri-implants with associated bone loss can have a negative effect on the long-term prognosis of the implant reconstruction. The rationale for soft-tissue grafting and vestibuloplasty techniques is presented in the form of a literature review. The implant sulcular epithelium, permucosal seal, and the peri-implant connective tissues are discussed. The etiology of soft-tissue complications as well as the significance of attached gingiva surrounding implant abutments are presented along with techniques for surgical intervention.

Dental Abutments↗
PubMed1995

Demonstration of smoking-related DNA damage in cervical epithelium and correlation with human papillomavirus type 16, using exfoliated cervical cells.

Smoking is a known aetiological risk factor for cervical cancer. Smoking-related DNA damage (DNA adducts), in cervical epithelial cells, has recently been demonstrated to suggest a causal role in the development of cervical cancer. Human papillomavirus 16 (HPV 16) is a known oncogenic virus and is also implicated as a cause of cervical cancer. It has been suggested that both smoking and HPV may act synergistically in the development of cervical cancer. We have investigated the cervical DNA adduct level and the prevalence of HPV 16 (using polymerase chain reaction) in women who had normal cervical cytology. Both the DNA adduct assay and the HPV assay were carried out on exfoliated cervical cells recovered from cervical scrapes. In 87% of the cases there was enough DNA from the exfoliative cervical cells to analyse for DNA adducts. Smokers had higher DNA adduct levels than non-smokers (P = 0.002), confirming the previous data from cervical biopsy samples. Forty-two per cent of the specimens were found to be HPV 16 positive. There was no significant difference in smoking-related DNA damage (DNA adduct levels) between HPV-positive and HPV-negative smokers. This suggests that smoking DNA damage does not augment HPV infectivity. These results do not, therefore, support the molecular synergism theory.

Adolescent↗
PubMed1995

Undergraduate education in implant dentistry.

A special interest group meeting devoted to clinical educational programs in implant dentistry for undergraduate students was held in March 1994 at the annual session of the American Association of Dental Schools in Seattle, Washington. Summaries of the presentations of representatives from three United States dental schools and the moderator's introductory remarks are included in this article.

Curriculum↗
PubMed1995

The microbial flora associated with stable endosseous implants.

Eleven patients with 36 stable endosseous implants in function for at least six months were selected for culturing in this study. Each patient had been restored with a mandibular implant-borne bar overdenture. The bacterial samples were taken from the superior aspect of the implants after bar and abutment removal. The plaque specimens contained predominantly Gram-positive microflora, although Gram-negative species were present in low numbers. This study serves to corroborate previously published reports regarding the characterization of the microflora associated with stable endosseous implants.

Actinomyces↗
PubMed1994

DNA adduct assay in cervical epithelium.

Numerous epidemiological studies have shown that there is an association between smoking and cervical cancer. However, the essential evidence to show whether this relationship is casual or causal is lacking. The demonstration of DNA modification by tobacco components in the cervical epithelium would provide biochemical evidence to support a causal role. In this study, DNA from 39 cervical biopsies was analysed for the presence of DNA adducts using the 32P-postlabeling technique. A questionnaire on smoking habit and a urinary cotinine assay were used to identify smokers and nonsmokers. DNA samples from smokers [identified from questionnaire] were found to have significantly higher adduct levels than nonsmokers (Mann-Whitney one-tailed U-test, 95% CI > 0.339, P = 0.024). Exclusion of the women whose urinary cotinine levels did not confirm their self-reported smoking status (smoker or nonsmoker) increased this significance (95% CI > 0.508, P = 0.01). Women who had abnormal cervical smears had significantly higher DNA adduct levels than those with normal smears (95% CI > 0.439, P = 0.015). Monitoring of women with high DNA adduct levels may be a way of identifying women at risk of cervical cancer. These findings demonstrate that tobacco smoking by women leads to elevated levels of DNA adducts in cervical epithelium and provides the biochemical evidence to support the concept that smoking is a cause of cervical cancer.

Adult↗
PubMed1994

Free gingival grafting and vestibuloplasty with endosseous implant placement: clinical report.

Soft-tissue complications may occur adjacent to endosseous implants and their associated transepithelial abutments. Vestibuloplasty and connective tissue grafting techniques can be used to obtain attached keratinized tissue in the anterior endentulous mandible before implant placement in an effort to improve the long-term prognosis. A clinical case is presented that was restored with a mandibular implant-supported, bar-retained overdenture opposing a maxillary complete denture after grafting and vestibuloplasty procedures.

Aged↗