bluuebunny/crossref_metadata_2025 huggingface dataset:
Fairness Reactions to Personnel Selection Methods: An international comparison between the Netherlands, the United States, France, Spain, Portugal, and Singapore
Authors: Anderson Neil , Witvliet Carlijn
Published: January 2008

This paper reports reactions to employee selection methods in the Netherlands and compares these findings internationally against six other previously published samples covering the United States, France, Spain, Portugal, and Singapore. A sample of 167 participants rated 10 popular assessment techniques using a translated version of Steiner and Gilliland's measure. In common with other country samples, we found that the most popular methods among applicants were interviews, work sample tests, and resumes. Least popular methods were graphology, personal contacts, and honesty and integrity tests. Generally, method favorability was found to be highly similar to the US and other published studies internationally. Across the six countries mean process favorability correlated at .87 and mean cross‐national procedural justice correlated .68. Process dimension ratings correlated at between .79 and .97 between the United States and the Netherlands. Only medium effect size differences (Cohen's d) were found between Dutch and US reactions to resumes and personality tests, the former being more favorably rated in the United States (d=.62) and the latter being more positively rated in the Netherlands (d=−.76). Implications for the design of selection procedures are discussed, especially implications for likely similarities and differences in applicant reactions internationally.
Selection Test Anxiety: Investigating applicants' self‐ vs other‐referenced anxiety in a real selection setting
Authors: Proost Karin , Derous Eva , Schreurs Bert , Hagtvet Knut A. , De Witte Karel
Published: January 2008

Test anxiety has received limited attention in personnel selection research, although it may impair the test performance of applicants. This paper describes the development and validation of a new two‐dimensional measure of applicants' test anxiety, namely the Self‐ versus Other‐Referenced Anxiety Questionnaire (SOAQ), that embeds worrisome cognitions of anxious applicants in the social evaluative context of ‘self’ (Self‐Referenced Anxiety) and ‘significant others’ (Other‐Referenced Anxiety). An exploratory factor analysis (calibration sample), followed by a confirmatory factor analysis (validation sample) and correlations with several proximal and distal theoretical constructs indicated satisfactory psychometric properties and construct validity for both SOAQ scales. Structural equation modeling further showed a differential impact of Self‐ and Other‐Referenced Anxiety on applicants' test performance within a real personnel selection context. The scientific and practical relevance of these findings are discussed.
Psychometric Correlates of FIRO‐B Scores: Locating the FIRO‐B scores in personality factor space
Authors: Furnham Adrian
Published: January 2008

This paper investigated the relationship between the six Fundamental Interpersonal Relations Orientation (FIRO)‐B scales, the Big Five Personality traits assessed by the NEO PI‐R, the Hogan Development Survey (HDS) and two measures of cognitive ability (Watson Glaser; Graduate and Managerial Assessment). It examined the concurrent and construct validity of the measure in various adult groups attending assessment centres in order to locate the FIRO‐B dimensions in established personality factor space. The FIRO‐B was consistently correlated with Extraversion, though analysis at the primary factor (facet) level showed many traits from all five factors were strongly correlated with the six FIRO‐B scores. Regressing the six FIRO‐B facets onto each of the Big Five in turn showed all were significant particularly for Expressed Inclusion and Wanted Control. The second study also showed considerable and logical overlap between the six FIRO‐B scales and the 11 dysfunctional personality strategies as measured by the HDS. There were also strong correlational patterns for the Cautious, Reserved, Colourful and Dutiful type disorders. The third study showed the FIRO‐B was statistically associated with both cognitive ability tests though it only accounted for small percentages of the explained variance. Expressed Control was the most consistently correlated of the intelligence test scores. Despite the fact that many explicable associations were found between the FIRO‐B and other measure the effect sizes were not large. Thus only 4% of the trait facet scores and 4.5% of the HDS showed medium effect sizes. Results are discussed in terms of the usefulness and possible discriminant validity of the instrument for use in selection and assessment.
Multisource Assessments of Behavioral Competencies and Selection Interview Performance
Authors: Darr Wendy , Catano Victor M.
Published: January 2008

This study sought to determine whether and how ratings of leadership in a developmental multisource feedback program compare against those obtained by leadership selection decision makers. Seventy‐seven senior managers received feedback on eight competencies that also formed the basis of a subsequent promotional interview for senior executive positions. Each rating source displayed a unique perspective on the participants, but only the supervisor and peer ratings predicted performance on the interview. As well, peer, subordinate, and self‐ratings failed to improve upon the supervisors' predictions. The results also suggested a general performance factor underlying both the multisource assessments and the interview ratings.
Immunohistochemical staining of human islet cells with region‐specific antibodies against secretogranins II and III
Authors: Stridsberg M. , Grimelius L. , Portela‐Gomes G. M.
Published: January 2008

Chromogranins and secretogranins belong to the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In earlier publications we have described the development of region‐specific antibodies against CgA and CgB. In this study we describe antibodies to SgII and SgIII and their usefulness for immunohistochemical staining. Peptides homologous to defined parts of secretogranins II and III were selected and synthesized. Antibodies were raised and immunostainings were performed on normal human pancreas. The SgII 154–165 (N‐terminal secretoneurin), SgII 172–186 (C‐terminal secretoneurin) and SgIII antibodies immunostained all insulin‐immunoreactive cells, most of the glucagon cells and some of the pancreatic polypeptide cells. The SgII 225–242 antibody immunostained only the insulin‐containing cells. None of the antibodies immunostained the somatostatin cells. This study is the first observation of the expression of SgIII in human tissues, where we show expression of SgIII in three of the four major islet cell types in human pancreas.
The pathways connecting the hippocampal formation, the thalamic reuniens nucleus and the thalamic reticular nucleus in the rat
Authors: Çavdar Safiye , Onat Filiz Y. , Çakmak Yusuf Özgür , Yananli Hasan R. , Gülçebi Medine , Aker Rezzan
Published: January 2008

Most dorsal thalamic nuclei send axons to specific areas of the neocortex and to specific sectors of the thalamic reticular nucleus; the neocortex then sends reciprocal connections back to the same thalamic nucleus, directly as well indirectly through a relay in the thalamic reticular nucleus. This can be regarded as a ‘canonical’ circuit of the sensory thalamus. For the pathways that link the thalamus and the hippocampal formation, only a few comparable connections have been described. The reuniens nucleus of the thalamus sends some of its major cortical efferents to the hippocampal formation. The present study shows that cells of the hippocampal formation as well as cells in the reuniens nucleus are retrogradely labelled following injections of horseradish peroxidase or fluoro‐gold into the rostral part of the thalamic reticular nucleus in the rat. Within the hippocampal formation, labelled neurons were localized in the subiculum, predominantly on the ipsilateral side, with fewer neurons labelled contralaterally. Labelled neurons were seen in the hippocampal formation and nucleus reuniens only after injections made in the rostral thalamic reticular nucleus (1.6–1.8 mm caudal to bregma). In addition, the present study confirmed the presence of afferent connections to the rostral thalamic reticular nucleus from cortical (cingulate, orbital and infralimbic, retrosplenial and frontal), midline thalamic (paraventricular, anteromedial, centromedial and mediodorsal thalamic nuclei) and brainstem structures (substantia nigra pars reticularis, ventral tegmental area, periaqueductal grey, superior vestibular and pontine reticular nuclei). These results demonstrate a potential for the thalamo‐hippocampal circuitry to influence the functional roles of the thalamic reticular nucleus, and show that thalamo‐hippocampal connections resemble the circuitry that links the sensory thalamus and neocortex.
REINTERPRETATION OF THE SILURIAN SCORPION PROSCORPIUS OSBORNI (WHITFIELD): INTEGRATING DATA FROM PALAEOZOIC AND RECENT SCORPIONS
Authors: DUNLOP JASON A. , ERIK TETLIE O. , PRENDINI LORENZO
Published: January 2008

Abstract:  The morphology of the Late Silurian (Přídolí) scorpion Proscorpius osborni (Whitfield, 1885a) (Arachnida: Scorpiones), from the Phelps Member of the Fiddlers Green Formation of New York, the ‘Bertie Waterlime’ of earlier stratigraphic schemes, is revised based on studies of new and existing material (a total of 32 specimens). Previous reports of four cheliceral articles, gnathobasic coxae, a labium and gill slits in P. osborni can be dismissed. However, we confirm the presence of both median and compound lateral eyes, a pair of tarsal claws, albeit on a more digitigrade foot compared to that of modern scorpions, more than five ventral mesosomal sclerites and a fairly modern pattern of metasomal (i.e. tail) carinae. The co‐occurring Archaeophonus eurypteroidesKjellesvig‐Waering, 1966 and Stoermeroscorpio delicatusKjellesvig‐Waering, 1986 are regarded as junior synonyms of P. osborni. Fossil scorpion higher systematics is plagued by a plethora of unnecessary and largely monotypic higher taxa and we draw on the results of Jeram’s cladistic analysis from 1998 to synonymize formally a series of families and superfamilies with Proscorpiidae Scudder, 1885.
Pertussis vaccination and epilepsy—an erratic history, new research and the mismatch between science and social policy
Authors: Shorvon Simon , Berg Anne
Published: January 2008

Summary

For over 50 years, concerns have been raised about the risk of pertussis vaccine‐induced childhood encephalopathy and epilepsy. This article reviews the scientific literature, and the social and historical context in which the scientific, public health and societal views have not always been aligned. Large‐scale studies of this issue have produced conflicting results, although the recent consensus is that the risk of vaccine‐induced encephalopathy and/or epilepsy, if it exists at all, is extremely low. Risk estimates in the literature have included: risk of a febrile seizure 1 per 19,496 vaccinations; risk of an afebrile seizure 1 per 76,133 vaccinations; risk of encephalopathy after pertussis infection nil—3 cases per million vaccinations. A recent study showed that encephalopathy in 11 out of the 14 children studied, although previously attributed to vaccination, was in fact due an inherited genetic defect of the SCNIA gene that codes for the voltage gated neuronal sodium channel. This study is important because it provides a solid alternative explanation for the perceived pertussis vaccine‐encephalopathy association. The interesting possibility is raised that the encephalopathy apparently due to pertussis itself may, in some cases, be due to an SCNIA mutation. It may also, by analogy, shed some light on the continuing debate about other serious long‐term adverse effects of vaccination in general.
Correlates of Urinary, Fecal, and Dual Incontinence in Older African‐American and White Men and Women
Authors: Markland Alayne D. , Goode Patricia S. , Burgio Kathryn L. , Redden David T. , Richter Holly E. , Sawyer Patricia , Allman Richard M.
Published: January 2008

OBJECTIVES: To determine prevalence and correlates of urinary (UI), fecal (FI), and dual (DI) incontinence in community‐dwelling older adults.

DESIGN: Cross‐sectional, population‐based in‐home survey.

SETTING: Three rural and two urban Alabama counties (1999–2001).

PARTICIPANTS: Stratified random sample of 1,000 Medicare beneficiaries aged 65 and older: 25% African‐American men, 25% white men, 25% African‐American women, 25% white women.

MEASUREMENTS: UI defined as involuntary urine loss at least monthly; FI defined as “In the past year, have you had any loss of control of your bowels, even a small amount that stained the underwear?” Independent variables were sociodemographics, medical history, and activities of daily living (ADLs) excluding toileting. Multinomial logistic regression models were constructed using UI, FI, and DI as dependent variables.

RESULTS: UI, FI, and DI prevalences were 27%, 6%, and 6%, respectively. White women had higher prevalence of UI (41.1% vs 24.6%, P<.001) and DI (18.5% vs 8.0%, P=.07) but not FI (4.4% vs 3.8%, P=.83) than African‐American women. Men had no racial differences in prevalence (UI 22.2%, FI 7.7%, DI 4.6%). In women, UI, FI, and DI correlates included higher Charlson comorbidity score and depressive symptoms and greater ADL difficulty for UI and DI. In men, UI was associated with prostate disease and depressive symptoms; FI with chronic diarrhea, history of transient ischemic attack (TIA), and poor self‐perceived health; and DI with history of TIA, foot and leg swelling, and depressive symptoms.

CONCLUSION: Women had racial differences as well as similar correlates of incontinence subtypes, whereas men did not.
Antioxidant Vitamin Supplement Use and Risk of Dementia or Alzheimer's Disease in Older Adults
Authors: Gray Shelly L. , Anderson Melissa L. , Crane Paul K. , Breitner John C. S. , McCormick Wayne , Bowen James D. , Teri Linda , Larson Eric
Published: January 2008

OBJECTIVES:To examine whether use of vitamins C or E alone or in combination was associated with lower incidence of dementia or Alzheimer's disease (AD).

DESIGN:Prospective cohort study.

SETTING:Group Health Cooperative, Seattle, Washington.

PARTICIPANTS:Two thousand nine hundred sixty‐nine participants aged 65 and older without cognitive impairment at baseline in the Adult Changes in Thought study.

MEASUREMENTS:Participants were followed biennially to identify incident dementia and AD diagnosed according to standard criteria. Participants were considered to be users of vitamins C or E if they self‐reported use for at least 1 week during the month before baseline.

RESULTS:Over a mean follow‐up±standard deviation of 5.5±2.7 years, 405 subjects developed dementia (289 developed AD). The use of vitamin E was not associated with dementia (adjusted hazard ratio (HR)=0.98, 95% confidence interval (CI)=0.77–1.25) or with AD (HR=1.04; 95% CI=0.78–1.39). No association was found between vitamin C alone (dementia: HR=0.90, 95% CI=0.71–1.13; AD: HR=0.95, 95% CI=0.72–1.25) or concurrent use of vitamin C and E (dementia: HR=0.93, 95% CI=0.72–1.20; AD: HR=1.00, 95% CI=0.73–1.35) and either outcome.

CONCLUSION:In this study, the use of supplemental vitamin E and C, alone or in combination, did not reduce risk of AD or overall dementia over 5.5 years of follow‐up.
Excellent Early and Late Outcomes of Aortic Valve Replacement in People Aged 80 and Older
Authors: Filsoufi Farzan , Rahmanian Parwis B. , Castillo Javier G. , Chikwe Joanna , Silvay George , Adams David H.
Published: January 2008

OBJECTIVES: To investigate early and late outcome of aortic valve replacement (AVR) in a large cohort of patients aged 80 and older.

DESIGN: Retrospective study of consecutive patients undergoing AVR using a computerized database based on the New York State Department of Health registry. Data collection was performed prospectively.

SETTING: University hospital (single institution).

PARTICIPANTS: One thousand three hundred eight patients undergoing AVR (231 (17.6%) aged ≥80, 1,077 (82.4%) <80).

MEASUREMENTS: Patient characteristics, hospital mortality, morbidity, length of stay and long‐term survival were analyzed.

RESULTS: Subjects aged 80 and older were more likely to be female, had a lower body mass index, and presented significantly more often with comorbidities such as heart failure, renal failure, and extensive aortic calcification. Crude hospital mortality was 5.2% (n=12) in subjects age 80 and older, compared with 4.5% (n=48) in those younger than 80 (P=.37). Respiratory failure occurred more frequently in those aged 80 and older. In multivariate logistic regression analysis, age of 80 and older was not a predictor of hospital mortality. The median length of stay was significantly higher in those aged 80 and older than in those younger than 80 (10 days vs 7 days, P=.01). Five‐year survival was 64±5% in those aged 80 and older, which was similar to that of the age‐ and sex‐matched general U.S. population.

CONCLUSION: Excellent results after AVR can be expected in patients aged 80 and older, with minimal increase in postoperative mortality and acceptable postoperative morbidity. Respiratory failure is the main postoperative complication in patients aged 80 and older. Recent advances in operative techniques and perioperative management have contributed to better surgical outcomes in these patients than found in historical reports.
Attitudes, Experiences, and Interest in Geriatrics of First‐Year Allopathic and Osteopathic Medical Students
Authors: Voogt Shannon J. , Mickus Maureen , Santiago Olga , Herman Sandra E.
Published: January 2008

A cross‐sectional survey was designed to assess interest in geriatric medicine of allopathic and osteopathic medical students and to determine whether their career interests were related to past experiences with and current attitudes toward older adults. The study was conducted at an allopathic and osteopathic medical school with 231 first‐year medical students. Experiences with elderly people were measured using survey questions assessing amount and quality of experiences with grandparents, as well as experiences caring for, volunteering with, or having a paid position working with older adults. Attitudes were measured using the University of California at Los Angeles Geriatric Attitudes Scale, revised for applicability to medical students. Interest in geriatrics was measured using a 4‐point scale. Overall, students expressed positive attitudes toward older adults. Past experiences, including positive relationships with older relatives (P<.001) and experiences providing care for older adults (P<.001), were related to more‐positive attitude scores toward elderly people. Students had low interest in geriatric medicine, but those with more‐positive attitudes were more likely to consider geriatrics as a career (odds ratio=8.18, P<.001). Furthermore, having prior experience caring for older persons increased interest in the field (P=.001). No significant differences were found between allopathic and osteopathic student interest in geriatrics or attitudes toward older adults. Efforts toward increasing the pool of future geriatricians and increasing positive attitudes toward older patients could be improved by providing quality experiences caring for and interacting with older adults before medical school training.
Kidney Transplantation in Elderly People: The Influence of Recipient Comorbidity and Living Kidney Donors
Authors: Wu Christine , Shapiro Ron , Tan Henkie , Basu Amit , Smetanka Cynthia , Morgan Claire , Shah Nirav , McCauley Jerry , Unruh Mark
Published: January 2008

OBJECTIVES: To examine the extent to which donor and recipient characteristics were associated with transplant outcomes in elderly kidney transplant recipients.

DESIGN: Retrospective review.

SETTING: Single university center.

PARTICIPANTS: One thousand one hundred two patients, including 266 patients aged 60 and older.

MEASUREMENTS: Recipient and donor characteristics and patient and graft outcomes.

RESULTS: Of the 1,102 patients included in this study, 266 (25%) were aged 60 and older, and 117 (11%) were aged 67 and older. According to Cox proportional hazards analysis, patient survival was worse in elderly recipients, although the survival outcome in the oldest group (ages 68–86) was comparable with that in their slightly younger peers (ages 61–67). Graft function did not differ according to age. Comorbidity was a significant predictor of patient survival in elderly recipients (hazard ratio (HR)=1.17, 95% confidence interval (CI)=1.03–1.34, P=.02) but not in the subset of elderly recipients of living donor kidneys (HR=1.01, 95% CI=0.8–1.3, P=.9).

CONCLUSION: Older adults can achieve good outcomes with kidney transplantation, although in recipients with significant comorbid illness, careful donor selection and selective use of living donors may be vital to achieving good outcomes.
Melatonin and Bright‐Light Treatment for Rest–Activity Disruption in Institutionalized Patients with Alzheimer's Disease
Authors: Dowling Glenna A. , Burr Robert L. , Van Someren Eus J. W. , Hubbard Erin M. , Luxenberg Jay S. , Mastick Judy , Cooper Bruce A.
Published: January 2008

OBJECTIVES: To test whether the addition of melatonin to bright‐light therapy enhances the efficacy in treating rest–activity (circadian) disruption in institutionalized patients with Alzheimer's disease (AD).

DESIGN: Randomized, controlled trial.

SETTING: Two nursing homes in San Francisco, California.

PARTICIPANTS: Fifty subjects (mean age 86) with AD.

INTERVENTION: Experimental subjects received 1 hour of morning light exposure (≥2,500 lux in gaze direction) Monday to Friday for 10 weeks and 5 mg melatonin (LM, n=16) or placebo (LP, n=17) in the evening. Control subjects (n=17) received usual indoor light (150–200 lux).

MEASUREMENTS: Nighttime sleep variables, day sleep time, day activity, day:night sleep ratio, and rest–activity parameters were determined using actigraphy.

RESULTS: Linear mixed models were employed to test the primary study hypotheses. No significant differences in nighttime sleep variables were found between groups. At the end of the intervention, the LM group showed significant improvement in daytime somnolence as indicated by a reduction in the duration of daytime sleep, an increase in daytime activity, and an improvement in day:night sleep ratio. The LM group also evidenced a significant increase in rest–activity rhythm amplitude and goodness of fit to the cosinor model.

CONCLUSION: Light treatment alone did not improve nighttime sleep, daytime wake, or rest–activity rhythm. Light treatment plus melatonin increased daytime wake time and activity levels and strengthened the rest–activity rhythm. Future studies should resolve the question of whether these improvements can be attributed to melatonin or whether the two zeitgebers interact to amplify efficacy.
Beliefs, Risk Perceptions, and Gaps in Knowledge as Barriers to Colorectal Cancer Screening in Older Adults
Authors: Berkowitz Zahava , Hawkins Nikki A. , Peipins Lucy A. , White Mary C. , Nadel Marion R.
Published: January 2008

OBJECTIVES: To assess beliefs and perceptions of risk about colorectal cancer (CRC) and gaps in knowledge about screening in adults aged 65 to 89.

DESIGN: A population‐based survey.

SETTING: United States.

PARTICIPANTS: A total of 1,148 respondents with no history of CRC, representing an estimated population of 31.6 million persons, who were stratified according to screening behavior (up to date (n=457) vs not up to date (n=691)) and age (65–74 vs 75–89).

MEASUREMENTS: The Health Information National Trends Survey (2003) questionnaire.

RESULTS: An estimated 25% of adults aged 65 to 89 had not heard of the fecal occult blood test, 17% had not heard of sigmoidoscopy or colonoscopy, and 42% were not up to date with either screening modality. Not visiting a healthcare provider in the previous year, not knowing about tests available for colon cancer, perceiving the arrangements to be checked for detecting colon cancer to be difficult, and not having an opinion about it and its cost, were significantly associated with not being up to date (each P<.03). Persons who were not up to date were frequently unaware of the importance of CRC screening, and often reported lack of a provider's recommendation to be screened (>75%). Lack of knowledge and awareness were more prevalent in those aged 75 to 89 than those aged 65 to 74.

CONCLUSION: Lack of knowledge and awareness and the absence of a physician's recommendation to be tested might explain not being up to date with CRC screening in adults in these age groups. These findings suggest a potential value for better communication between older adults and their providers regarding screening for CRC, when appropriate.
Psychometric Properties of the Activities‐Specific Balance Confidence Scale and the Survey of Activities and Fear of Falling in Older Women
Authors: Talley Kristine M.C. , Wyman Jean F. , Gross Cynthia R.
Published: January 2008

OBJECTIVES: To compare the psychometric properties of the Activities‐specific Balance Confidence Scale (ABC) and the Survey of Activities and Fear of Falling in the Elderly (SAFE).

DESIGN: Secondary analysis using baseline and 12‐week data from a randomized, controlled trial on fall prevention.

SETTING: Upper Midwest metropolitan area with assessments conducted in participants' homes.

PARTICIPANTS: Population‐based sample of 272 noninstitutionalized female Medicare beneficiaries aged 70 and older at risk of falling.

MEASUREMENTS: Participants self‐administered the ABC, SAFE, Geriatric Depression Scale, and Medical Outcomes Study 36‐item Short Form Survey. During a home visit, a nurse practitioner administered the Berg Balance Test and Timed Up and Go, measured gait speed, and asked about falls and chronic illnesses.

RESULTS: Baseline internal consistency measured using Cronbach alpha was 0.95 for the ABC and 0.82 for the SAFE. Baseline concurrent validity between the ABC and SAFE measured using a correlation coefficient was −0.65 (P<.001). ABC and SAFE scores were significantly correlated at baseline with physical performance tests and self‐reported health status. The ABC had stronger baseline correlations than the SAFE with most measures. Neither instrument demonstrated responsiveness to change at 12 weeks.

CONCLUSION: The ABC and SAFE demonstrated strong internal‐consistency reliability and validity when self‐administered. The ABC had stronger associations with physical functioning and may be more appropriate for studies focused on improving physical function. Both instruments demonstrated ceiling effects, which may explain the lack of responsiveness to change in relatively nonfrail older women. Instruments sensitive to measuring lower levels of fear of falling are needed to capture the full range of this phenomenon in this population.
Voluntary Listing Requirements and Corporate Performance: The Case of the Dey Report and Canadian Firms
Authors: Panasian Christine , Prevost Andrew K. , Bhabra Harjeet S.
Published: January 2008

We investigate the determinants and consequences of compliance with the Dey Committee recommendations encouraging greater board independence in Canada. Companies that acted on this recommendation appear to have done so to improve their performance and not for cosmetic purposes. Poorly performing firms that modified their boards experienced a greater increase in performance compared to those that did not. Overall, it appears that the primary function of the Dey Report was to refocus firms' attention on the quality of board monitoring, particularly those with poor relative performance.
Adaptation of the Fungal Parasite Zygorhizidium planktonicum During 200 Generations of Growth on Homogeneous and Heterogeneous Populations of Its Host, the Diatom Asterionella formosa1
Authors: DE BRUIN ARNOUT , IBELINGS BAS W. , KAGAMI MAIKO , MOOIJ WOLF M. , VAN DONK ELLEN
Published: January 2008

ABSTRACT. We followed adaptation of the chytrid parasite Zygorhizidium planktonicum during 200 generations of growth on its host, the freshwater diatom Asterionella formosa, in a serial passage experiment. Evolution of parasite fitness was assessed both on a homogenous and heterogeneous host population, consisting of respectively a single new and ten different new host strains. These 10 host strains were genetically different and also varied in their initial susceptibility to the parasite. Parasite fitness increased significantly and rapidly on the new, genetically homogenous host population, but remained unaltered during 200 generations of growth on the heterogeneous host population. Enhanced parasite fitness was the result of faster and more efficient transmission, resulting in higher values of R0 (number of secondary infections). Consequently, parasites that evolved within the uniclonal host population infected significantly more of these hosts than did their ancestors. We thus provide experimental evidence for the widely held view that host genetic diversity restricts evolution of parasites and moderates their harmful effects. Genetically uniform host populations are not only at increased risk from fungal epidemics because they all share the same susceptibility, but also because new parasite strains are able to adapt quickly to new host environments and to improve their fitness.
The Search Finds an End: Colpodidiids Belong to the Class Nassophorea (Ciliophora)
Authors: BREINER HANS‐WERNER , FOISSNER WILHELM , STOECK THORSTEN
Published: January 2008

ABSTRACT.At its discovery in 1982, the ciliate genusColpodidiumwas assigned to the Class Colpodea. Redescriptions of the type speciesColpodidium caudatumcaused the establishment of a new family (Colpodidiidae). Based on ontogenetic data, eventually a new order—Colpodidiida—was established and hypothesized to belong to the Class Nassophorea. Despite a remarkable increase in the number of colpodidiid species, no sequence data were available to confirm or reject either class assignment or to assess the phylogenetic validity of the Colpodidiidae and the Colpodidiida. We here retrieved and phylogenetically analyzed the SSrDNA sequences ofC. caudatumfrom a Namibian soil and an as‐yet undescribed colpodidiid ciliate from the Chobe River floodplain, Botswana. Bayesian inference methods and evolutionary distance analyses confirmed the assignment of these taxa to the class Nassophorea.
Combined treatment of acute subretinal haemorrhages with intravitreal recombined tissue plasminogen activator, expansile gas and bevacizumab: a retrospective pilot study
Authors: Meyer Carsten H. , Scholl Hendrik P. , Eter Nicole , Helb Hans‐Martin , Holz Frank G.
Published: January 2008

Purpose:  To assess the effectiveness of consecutive intravitreal injections of recombined tissue plasminogen activator (rtPA), expansile gas and bevacizumab in eyes with acute subretinal haemorrhage (SRH).

Methods:  A retrospective, non‐randomized consecutive case series included 19 eyes in 19 patients with SRH related to exudative age‐related macular degeneration (AMD). The initial size of the subfoveal SRH was 1–3 disc diameters. Each patient received a triple procedure using 0.05 ml rtPA (50 μg), 0.3 ml of sulphur hexafluoride (SF6) gas and 0.05 ml bevacizumab (1.25 mg). Lesion size, location of the SRH and early treatment in diabetic retinopathy study (ETDRS) visual acuity were evaluated pretreatment as well as 1 and 3 months after the procedure.

Results:  At the initial presentation, the patients’ mean age was 77 years (range 63–88 years) and the mean duration of symptoms was 9.3 days (range 4–12 days). The mean visual acuity pretreatment (20/133) improved significantly to 20/86 at 1 month and to 20/74 at 3 months. The mean ETDRS visual acuity improved from baseline by 2.1 lines at 1 month (Wilcoxon ranks test; P < 0.005) and 3.7 lines at 3 months after treatment (Wilcoxon ranks test; P < 0.005). None of our patients had reading visual acuity prior to treatment, with visual acuity below 0.3. One month after the triple procedure, 25% of our patients had reading visual acuity (≥ 0.4); at 3 months, the figure was 35%. A successful inferior displacement of the SRH was achieved in 17/19 eyes. Eyes with elevated intraocular pressure were treated immediately by a corneal paracentesis.

Conclusion:  The intravitreal application of rtPA, gas and bevacizumab appears to be beneficial and well tolerated in the treatment of SRH in the short term. The triple approach seems a logical alternative to the current combined dual approach in limiting the progression of the underlying disease and achieving better visual outcome. Further randomized evaluations are warranted.
Formation of stromal collagen fibrils and proteoglycans in the developing zebrafish cornea
Authors: Akhtar Saeed , Schonthaler Helia B. , Bron Anthony J. , Dahm Ralf
Published: January 2008

Purpose: Collagen fibrils and proteoglycans are the main components of the corneal extracellular matrix and corneal transparency depends crucially on their proper arrangement. In the present study, we investigated the formation of collagen fibrils and proteoglycans in the developing cornea of the zebrafish, a model organism used to study vertebrate embryonic development and genetic disease.

Methods: We employed thin‐section electron microscopy to investigate the ultrastructure of the zebrafish cornea at different developmental stages.

Results: The layering of the zebrafish cornea into an epithelium, a Bowman’s layer, stroma and endothelium was observed starting at 72 hr post‐fertilization. At this stage, the stroma contained orthogonally arranged collagen fibrils and small proteoglycans. The density of proteoglycans increased gradually throughout subsequent development of the cornea. In the stroma of 2‐week‐old larvae, the collagen fibrils were organized into thin lamellae and were separated by very large, randomly distributed proteoglycans. At 4 weeks, a regular arrangement of proteoglycans in relation to the collagen fibrils was observed for the first time and the lamellae were also thickened.

Conclusion: The present study, for the first time, provides ultrastructural details of collagen fibril and proteoglycan development in the zebrafish cornea. Furthermore, it directly correlates the collagen fibril and proteoglycan composition of the zebrafish cornea with that of the human cornea. The similarities between the two species suggest that the zebrafish could serve as a model for investigating the genetics of human corneal development and diseases.
Short‐term clinical results of Nobel Direct implants: a retrospective multicentre analysis
Authors: Sennerby Lars , Rocci Antonio , Becker William , Jonsson Lars , Johansson Lars‐Åke , Albrektsson Tomas
Published: January 2008

Purpose: The present retrospective clinical study was undertaken to evaluate the survival rate and marginal bone conditions around Nobel Direct one‐piece implants. The purpose was also to compare the results with when these implants are used for immediate/early loading with implants allowed to heal before loading.

Material and methods: Forty‐three consecutive patients previously treated with 117 Nobel Direct implants at four different centres were evaluated. The implants had been used in both jaws for treatment after loss of single and multiple teeth. Immediate/early loading (within 2 weeks) with a provisional crown/bridge was applied to 95 implants, while 22 implants healed unloaded for 6 weeks to 6 months before loading. Calculations of marginal bone loss were performed in radiographs taken at placement and after an average of 10.2 months (range 1–18 months) of loading.

Results: Six (5.1%) of the 117 implants were removed during the follow up. All failed implants belonged to the immediate/early loading group giving a failure rate of 6.3% for this group and 0% for two‐stage implants. The failure rate was higher for flapless (7.9%) than for flap surgery (0%). The marginal bone loss was −2.4 mm (SD 1.5) for all implants, while 37.6% showed more than 3 mm of loss during the follow up. Bone loss increased with time of follow up. Implants subjected to immediate/early loading showed more bone loss than two‐stage implants: −2.6 mm (SD 1.5) vs. −1.6 mm (SD 1.1). Moreover, 41.3% of immediately loaded and 22.7% of two‐stage implants presented with more than 3 mm of bone loss.

Conclusions: This short‐term retrospective analysis showed a poor clinical outcome of Nobel Direct implants. Extensive marginal bone loss (>3 mm) was found around more than 1/3 of the implants evaluated. Less resorption and no failures were experienced when implants were allowed to heal from 6 weeks to 6 months before occlusal loading. Within the limitations of the present study design, data indicate that immediate loading, the use of this implant for multi‐unit constructions and flapless surgery are risk factors for failure of Nobel Direct implants.
Step‐wise analysis of the dental implant insertion process using the finite element technique
Authors: Van Staden Rudi C. , Guan Hong , Johnson Newell W. , Loo Yew‐Chaye , Meredith Neil
Published: January 2008

Objectives: Using the finite element method (FEM), the insertion process of a dental implant into a section of the human mandible is analysed. The ultimate aim of this article is to advance the use of an innovative engineering approach in dental practices, especially in the process of dental implantation.

Material and methods: The FEM and analysis techniques are used to replicate and evaluate the stress profile created within the mandible during the implantation process.

Results: The von Mises stress profiles in both cancellous and cortical bone are examined during implant insertion. The applied torque and the insertion stage are found to strongly influence the resulting stress profile within the surrounding jawbone.

Conclusions: Through the combination of both dental and engineering expertise, a simplified and efficient modelling technique is developed. This improves the understanding of the biomechanical reaction that the jawbone exhibits due to the insertion of implant. The current research is a pilot study using the FEM to model and simulate the dental implantation process. The assumptions made in the modelling and simulation process are: (1) the implantation process is simulated as a step‐wise process instead of a continuous process; (2) the implant is parallel threaded and the implant does not rotate during insertion into the jawbone. Although the modelling and simulation techniques had to be simplified, a significant amount of information is gained that helps lay a good foundation for future research. Recommendations for future studies include the variation of the torque applied during the implantation process and upgrading the software capabilities to simulate the full dynamical process of implantation.
Immediately loaded titanium implant with a tissue‐stabilizing/maintaining design (‘beyond platform switch’) retrieved from man after 4 weeks: a histological and histomorphometrical evaluation. A case report
Authors: Degidi Marco , Iezzi Giovanna , Scarano Antonio , Piattelli Adriano
Published: January 2008

Background: After implant insertion and loading, crestal bone usually undergoes remodeling and resorption. If the horizontal relationship between the outer edge of the implant and a smaller‐diameter component (‘platform switching’) is altered, there seems to be reduced crestal bone loss. Immediate loading allows immediate restoration of esthetics and function, reduces morbidity, and facilitates functional rehabilitation.

Materials and methods: Three Morse cone connection implants were inserted in the right posterior mandible in a 29‐year‐old partially edentulous patient. The platform of the implant was inserted 2 mm below the level of the alveolar crest. After a 1‐month loading period, the most distal mandibular implant was retrieved with a trephine bur for psychological reasons.

Results: At low‐power magnification, it was possible to see that bone was present 2 mm above the level of the implant shoulder. No resorption of the coronal bone was present. No infrabony pockets were present. At the level of the shoulder of the implant, it was possible to observe the presence of dense connective tissue with only a few scattered inflammatory cells. Newly formed bone was found in direct contact with the implant surface. The bone–implant contact percentage was 65.3±4.8%.

Conclusions: Abutments smaller than the diameter of the implant body (platform switching) in combination with an absence of micromovement and microgap may protect the peri‐implant soft and mineralized tissues, explaining the observed absence of bone resorption. Immediate loading did not interfere with bone formation and did not have adverse effects on osseointegration.
Osteoprotegerin levels in peri‐implant crevicular fluid
Authors: Arıkan Fatih , Buduneli Nurcan , Kütükçüler Necil
Published: January 2008

Aims: To evaluate the levels of soluble receptor activator of nuclear factor‐κB ligand (sRANKL) and osteoprotegerin (OPG) in crevicular fluid of endosseous dental implants.

Methods: Eighty‐six implants in 39 patients were evaluated. All patients were treated with root‐type implants placed at least 16 months and loaded at least 12 months before the examination. Peri‐implant crevicular fluid (PICF) samples were obtained from buccal and lingual aspects of implants. Modified plaque index, probing depth, gingival index, and bleeding on probing (BOP) were recorded at four sites per implant. PICF levels of sRANKL and OPG were analysed by ELISA. Spearman's correlations were utilised to relate biochemical data and clinical parameters.

Results: The PICF level of sRANKL did not show significant correlation with the clinical parameters or the OPG level. The total amount of OPG was positively correlated with PICF volume, gingival index, and BOP (P<0.05) and negatively correlated with pack years (P<0.05).

Conclusion: The findings of this preliminary study suggest that the crevicular fluid level of OPG deserves further investigation as a possible marker to evaluate the health status of surrounding tissues of dental implants, as this was not the case for the sRANKL level. Larger scale studies, particularly in peri‐implantitis cases, may shed more light on this subject.
Surgical factors influencing mesiodistal implant angulation
Authors: Payer Michael , Kirmeier Robert , Jakse Norbert , Pertl Christof , Wegscheider Walther , Lorenzoni Martin
Published: January 2008

Objectives: The aim of this experimental study was to identify relevant surgical parameters influencing the mesiodistal angular deviation of dental implants.

Material and methods: Pilot drillings of 2 mm diameter were performed in bovine ribs with a parallelometer. The subsequent preparation of the implant socket was performed freehand. Utilizing six different implant systems, at least 80 drillings per system of different diameters were performed. The pilot drillings were marked with 2 mm steel pins and cephalometric radiographs were taken. The mesiodistal angle between the longitudinal implant axis and the marked pilot drillings was measured and evaluated by a blinded investigator. To evaluate the influence of the surgeons' experience, their drillings were compared with those of a group of unexperienced surgeons. Additionally, the influence of drilling speed and size of bur steps on drilling accuracy were evaluated.

Results: The difference between the lowest value of 0.91° of mesiodistal angular deviation found for 3i® implants and the highest of 1.36° for Ankylos® implants was of low statistical significance (P=0.065). Drillings of experienced surgeons showed less deviation compared with those of a beginners group (P<0.0001). Higher deviations were measured when a bur size was skipped. Drillings performed at high speed showed significantly higher deviations than those with fewer rewinds per minute.

Conclusion: In order to achieve precise implant angulation, all bur diameters available should be used. Utilizing low drilling speeds results in less mesiodistal deviation. The surgeon's experience seems to be the most relevant factor in precise implant placement.
Dental implants placed in previously failed sites: survival rate and factors affecting the outcome
Authors: Machtei Eli E. , Mahler Dan , Oettinger‐Barak Orit , Zuabi Otman , Horwitz Jacob
Published: January 2008

Objectives: The purpose of the present study was to evaluate the survival rate of dental implants in previously failed implant sites. In addition, factors that might affect the outcome of these redo procedures were also explored.

Material and methods: Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Data on the failed implants were collected. The same parameters, along with the interval between retrieval and re‐implantation, were collected for the second set of implants. Descriptive statistics were used to describe the patients and implants. Life table analysis of these implants was tabulated for both implant sets. The effect of systemic, environmental and local factors on the survival of the redo dental implants was evaluated.

Results: Fifty‐six patients with a total of 79 redo implants were included in this study. Implants were followed for 7–78 months (mean 29.9±2). Thirteen implants failed that resulted in an overall survival rate of 83.5%. Successful implants had greater diameter (4.05±0.52 mm) than failed implants (3.72±0.56 mm); however, these differences were only marginal (P=0.06). Conversely, smoking habits, implants length and location, mode of placement and spontaneous exposure did not have a significant effect on the outcome of this procedure.

Conclusion: Redo of dental implants has a lesser survival rate compared with previous reports for implants in pristine sites. These results were not associated with most implant‐ and/or patient‐related factors. Thus, a possible negative effect that is associated with the specific implant's site might account for this phenomenon.
Effect of polyphosphoric acid pre‐treatment of titanium on attachment, proliferation, and differentiation of osteoblast‐like cells (MC3T3‐E1)
Authors: Maekawa Kenji , Yoshida Yasuhiro , Mine Atsushi , Van Meerbeek Bart , Suzuki Kazuomi , Kuboki Takuo
Published: January 2008

Purpose: To evaluate the effect of polyphosphoric acid (PPA) pre‐treatment of titanium (Ti) on the initial attachment, proliferation, and differentiation of mouse osteoblast‐like cells (MC3T3‐E1).

Materials and methods: Adsorption of PPA to Ti was achieved by immersing Ti disks (15 mm in diameter) into 0, 1, and 10 wt% PPA and 10 wt% orthophosphoric acid (OPA) for 24 h. On each pre‐treated Ti disk, 5.0 × 104 MC3T3‐E1 cells were seeded, and 1, 3, and 5 h later cell attachment was evaluated. Cell proliferation was also determined 1, 3, and 5 days after cell seed. Cell differentiation was evaluated 5, 10, and 15 days after cell seed using osteoblast marker gene expression. Total RNA was purified from each culture and Type‐I collagen, alkaline phosphatase, and osteocalcin mRNA expression levels were measured by real‐time reverse transcription polymerase chain reaction.

Results: Adsorption of PPA or OPA to Ti significantly accelerated initial cell attachment at every time point (P<0.0001). As with cell attachment, cell proliferation was also accelerated on the PPA‐treated Ti disks in a dose‐dependent manner at every time point (P<0.0001). However, OPA‐treated Ti disks did not enhance the cell proliferation. Regarding osteoblastic differentiation, PPA‐treated Ti significantly accelerated the Type‐I collagen gene expression at 5 and 10 days after cell seed. Regarding alkaline phosphatase and osteocalcin gene expression, no significant difference was found among the different Ti surface conditions.

Conclusion: The accelerated cell behavior following Ti pre‐treatment with PPA is a promising new strategy to fabricate bioactive Ti implants.