bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability of color doppler imaging parameters and consequences for sample size calculations
Authors: VANDEWALLE E , SIESKY B , ZEYEN T , HARRIS A , STALMANS I
Published: November 2009

Purpose The aims of this study were: 1) to determine the intra‐observer variability of color Doppler imaging (CDI) measurements, 2) to compare the difference in variability of these measurements in healthy controls versus glaucoma patients, and 3) to provide calculations of minimum sample sizes for future CDI studies.

Methods Patients with normal tension glaucoma (n=28), primary open angle glaucoma (n=19) and age‐matched healthy controls (n=22)underwent CDI on two occasions one month apart. Variability in CDI measurements was quantified using (within‐subjects) coefficients of variation. Based on this variability, minimum sample sizes were calculated to guide the design of future studies comparing CDI between and within groups.

Results In general, within‐subject coefficients of variation for measurements one month apart were comparable to previously reported short‐term variations. Variability was higher in glaucoma patients than in healthy controls. The minimum sample size required for glaucomatous study populations is larger than for healthy controls. Smaller patient groups are required to detect change using the peak systolic velocities than using end diastolic velocities. Studies using a cross‐over design require smaller sample sizes than studies with a pre‐post or parallel design.

Conclusion This study provides extensive information on long‐term intra‐observer variability of CDI measurements in healthy controls as well as glaucoma patients. Moreover, sample size calcualtions are provided for studies involving glaucoma patients as well as healthy individuals using three different study designs.
Selection and assessment of vital dyes to improve the endothelial quality control of organ cultured corneas
Authors: THURET G , DUBAND S , CAMPOLMI N , PIPPARELLI A , PISELLI S , DUMOLLARD JM , PEOC'H M , ACQUART S , GARRAUD O , GAIN P
Published: November 2009

Purpose In eye banks, corneal quality control requires an accurate endothelial cell density (ECD). ECs are counted after osmotic preparation (NaCl/sucrose) that makes cells visible. Nevertheless, endothelial images remain often poorly contrasted, non uniform, with a high background noise. Aim: to replace this technique by a non toxic ‘endothelial dye’

Methods 30 dyes were pre‐selected. Ability to stain EC was assessed on porcine, bovine and rabbit corneas. They were exposed (1 min) to pure or diluted dyes and observed under a light microscope using bright field and 4 standard fluorescent filters. Toxicity was assessed in vitro on EC cultures (live/dead assay, Hoechst Ethidium Calcein). Using the same assay, the less toxic dyes were further assessed on keratocytes cultures and on animal corneas organ cultured for 24H after exposure to dyes. Controls: exposure to BSS only or 3% H2O2

Results Only Ledermycin, Hemalun, Rose Bengal, Nuclear Red, Congo red, Evans Blue, and Chicago Sky Blue (CSB) stained ECs, and only the 3 diazoïc dyes (Congo red, Evans Blue, and CSB) stained EC borders using fluorescence (Em554/Ex568nm). Both blue dyes also stained the nuclei of dead cells. Hemalun and Rose Bengal were highly toxic. In vitro and ex vivo toxicity of CSB was negligible. The other dyes had an intermediate toxicity

Conclusion Diazoïc dyes and especially CSB could be non toxic dyes for ECs borders. They could improve the accuracy of ECD determination. Their ability to stain human endothelium and their safety (using an animal graft model) have to be assessed as well as their contribution in ECD determination versus the classical osmotic endothelial preparation
25‐hydroxycholesterol increases IL‐8 production in the RPE by activation of PI3K and p38 MAPK pathways
Authors: FERNANDES AF , BRITO A , PEREIRA P
Published: November 2009

Purpose Cholesterol oxides have been implicated in the overproduction of proinflammatory cytokines, such as IL‐8. The purpose of this study is to establish whether cholesterol oxides increase IL‐8 production in the RPE and elucidate the molecular mechanism underlying that increase.

Methods Cultured RPE (ARPE‐19) cells were incubated with 7‐ketocholesterol (7‐KC) and 25‐hydroxycholesterol (25‐OH). Levels of phosphorylated Akt and p38 MAPK in the cells were determined by Western blotting. Levels of IL‐8 mRNA were assessed by real‐time RT‐PCR. IL‐8 protein levels in the medium were determined by ELISA.

Results 25‐OH increases IL‐8 gene expression and secretion in a time‐dependent manner, whereas 7‐KC does not have a significant effect on IL‐8 production. This effect is not suppressed by antioxidants. Inhibition of the PI3K pathway using either chemical inhibitors or dominant negative forms of PI3K prevents the 25‐OH‐induced IL‐8 production. Inhibition of the p38 MAPK only partially reverses this effect on IL‐8 production. Consistently, 25‐OH activates Akt in RPE cells, whereas only a modest increase on phosphorylated p38 MAPK is observed. Data further indicates that NF‐kB is not involved in IL‐8 production following treatment with 25‐OH.

Conclusion 25‐OH increases IL‐8 production in RPE by a mechanism that requires activation of PI3K and p38 MAPK and does not involve oxidative stress. The effectors downstream of Akt and p38 MAPK remain unknown. This IL‐8 increase may account for the proinflammatory properties of cholesterol oxides in retinal diseases, such as AMD. Supported by FCT grants SFRH/BD/19039/2004 and POCI/SAU‐OBS/57772/2004
Quantification of sphero‐cylindrical defocus using refractive data
Authors: TOUZEAU O , GAUJOUX T , KOPITO R , COSTANTINI E , BORDERIE VM , LAROCHE L
Published: November 2009

Purpose To compare various indices calculated using refractive data to quantify defocus.

Methods Subjective refraction, pupil diameter (Colvard) and asphericity (Orbscan) were prospectively recorded in 200 healthy eyes (including ametropia) of 121 patients. Refractive data were expressed by a sinusoidal curve in one plane (power / meridian) and by a vector in a 3D dioptric power space. The three Cartesian coordinates of the vector respectively represented the spherical equivalent, WTR/ATR component (0°/90° Jackson), and oblique component (45°/135° Jackson). The defocus was quantified by the root‐mean‐square (RMS) value of the power curve and the length of the vector. Correlations between uncorrected visual acuity (UCVA) in LogMAR units and principal parameters including defocus indices and refractive parameters were analyzed.

Results The length of the power vector and the RMS index provided the highest correlation with UCVA (rs=0.90 p<0.001 and rs=0.88 p<0.001, respectively), whereas the correlation was less strong for subjective spherical equivalent (rs=0.70 p<0.001) and subjective cylinder (rs=0.30 p<0.001). Correlation was poor for the pupil diameter (rs=0.20, p<0.001); sex and asphericity coefficient showed no significant correlation (rs<0.08 p>0.20) with UCVA.

Conclusion The length of the sphero‐cylindrical vector is clinically relevant to quantify the defocus with the aid of a single index using both spherical and astigmatic components of refraction. The UCVA is mainly explained by the ametropia.
Methods of screening
Authors: VUJOSEVIC S
Published: November 2009

Diabetic retinopathy (DR) is one of the leading causes of adult blindness in working age population worldwide due to its late diagnosis and treatment. In effort to early detect DR, before visual loss, international guidelines for DR screening recommend an annual fundus examination for all diabetic patients. A variety of techniques can be used to detect and classify DR, including direct and indirect ophthalmoscopy, stereoscopic color film fundus photography, mydriatic and nonmydriatic (NM) digital color and monocromatic photography. Although ophthalmoscopy is the most commonly used technique to screen for DR, it has poor sensitivity when performed by nonophthalmologists in nonmydriatic conditions. The sensitivity of direct ophthalmoscopy in detecting proliferative DR is about 50% when performed by non‐ophtahlmologists in NM conditions. Seven‐field stereoscopic color fundus photographies have been considered as reference standard for diagnosing DR in randomized clinical trials. But this method is time consuming with uncertain practicity for widespread screening programs. Several studies have reported sensitivity and specificity in detecting DR and diabetic macular edema (DME) using limited number of fundus fields, proposing an alternative method for diabetic retinopathy evaluation to the ETDRS 7 fields. Recently introduced telemedicine screening programs based on digital images have the potential to allow for increased detection of DR, resulting in timely treatment and preservation of vision. Also important cost savings have been reported with DR screening, either by manual (human) or automatic (computer‐based) grading. Therefore, there is a critical need for a sensitive, specificic and cost‐effective screening method.
A 3 year retrospective case series of temporal arteritis in Portsmouth, United Kingdom
Authors: TRIKHA S , LOCKWOOD A , BUCHANAN E , KIRWAN JF
Published: November 2009

Purpose To investigate the incidence,socioeconomic status and inflammatory markers of patients with biopsy proven Temporal(Giant Cell)Arteritis(GCA)in Portsmouth, United Kingdom.

Methods A single‐centre retrospective study assessed patients referred for Temporal Artery biopsy.Serum platelet count,Erythrocyte Sedimentation Rate (ESR)and C‐Reactive Protein(CRP)were analysed. Socioeconomic status was investigated using index of deprivation scores from the national database and compared to a cataract surgery group(control). Patients received high dose oral prednisolone or intravenous methylprednisolone initially,followed by oral prednisolone.Telephone survey follow‐up for biopsy positive patients assessed smoking history and subjective visual improvement following treatment.

Results 70% of biopsies were negative. Biopsy positive age adjusted incidence was 29.3/100000.93% of cases referred were subsequently diagnosed with GCA on clinical grounds.Mean platelet count was 359.7(B‐ve)vs.438.8(B+ve)(p≤0.001),mean CRP 50.75(B‐ve)vs.98.0(B+ve)(p≤0.001)and mean ESR was 53.9(B‐ve)vs.69.9(B+ve)(p≤0.018). Insignificant differences in socioeconomic status were found in biopsy positive group compared to controls(p=0.112).33% of biopsy positive patients sustained Visual loss, all patients reported unchanged Visual function, irrespective of treatment regime.

Conclusion Biopsy +ve GCA was associated with significant elevations in serum platelet count,ESR and CRP levels compared to B‐ve GCA. The incidence in Portsmouth appears higher than other Caucasian populations. GCA appears unrelated to socioeconomic status in this cohort. A large proportion of biopsies were negative or inconclusive – warranting a strict referral pathway to ease pressure on Ophthalmic services.
Electrogenesis of the retina in proceeding glaucomatous optical neuropathy
Authors: VAZHENKOV SN , SHAMSHINOVA AM
Published: November 2009

Purpose to investigate some branches of the pathogenetic mechanisms of eye function’s disturbance in patients with the glaucomatous optic neuropathy(GON) with normalized intraocular pressure(IOP)

Methods 12 p‐s(23 eyes) with primary open angle glaucoma(POAG) of I‐IIIa study and normalized IOP by conservative treatment or after operation and 7 healthy volunteers were investigated. Standard (ISCEV) methods of record of the electroretinogram (ERG)and the original method of the oscillatory potentials (OPs) recording in light adaptation were used. Oscillations O1,O2 and O3 of the flicker 30Hz ERG were filtered on frequencies of 80 and 120Hz(MBN’s equipment). Heidelberg retinal tomography(HRT), central field perimetry(CFP) on 30(Humphry) also were used

Results The correlation between decreasing of O3 and increasing of excavation of the optic nerve disc by HRT‐data was obtained. Attenuation of amplitude of cones’ oscillations O1 and O2 was linked with magnification of the degree of CFP’s declension from the age norm (PSD). Decreasing of O1‐oscillation amplitude was linked with the increasing of average elevation of CFP threshold mean(MD)

Conclusion 1.The genesis of the O1, O2 and O3 in flicker 30Hz ERG is differ in comparing with the genesis of OPs registered in dark adaptation, and is linked with the light on and dark off‐channels of the cone retinal system. 2.Appearing indices of the retinal ischemia O1, O2 and O3, picked out from the flicker 30Hz ERG, show the link with the functional state of the retinal neurons in the light on‐ and dark off‐channels of midget pathway. The O3‐oscillation displays the neuronal links disturbance of the ganglion cells that is proving the degree of apoptosis’ evolution
Regulatory T‐cells induce an immune escape in a murine model of primary intraocular B‐cell lymphoma
Authors: TOUITOU V , BODAGHI B , DAUSSY C , DONNOU S , LEHOANG P , FRIDMAN WH , FRIDMAN C , FISSON S
Published: November 2009

Purpose The role of regulatory T cells (Tregs) in the immune evasion of tumors is usually prominent. The aim of this study was to assess the presence and role of Tregs in a murine model of primary intraocular B‐cell lymphoma (PIOL).

Methods We used a syngeneic model of PIOL in immunocompetent BALB/c mice. Immunohistochemistry and flow cytometric analysis have been performed to study the tumor growth and the immune infiltrate. Depletion of Tregs was achieved using intraperitoneal injection of anti‐CD25 mAb (PC61). Splenectomy was performed to study the role of induced Tregs.

Results Tregs were recruited in PIOL eyes (16.2%) compared to control eyes (1.2%, p<0.001). The number of infiltrating Tregs was correlated with tumor burden (r2=0.76), and inversely correlated with CD4+ T‐cells (r2=‐0.79). Recruitment of Tregs was also observed in the spleen of mice bearing tumor (2.9%) compared to controls (2.1%, p<0.001), but not in the draining lymph nodes. Depletion of Tregs resulted in a significant decrease of tumor burden (53.8% in control mice compared to 37.7% in PC61 mice, p=0.03), and an increase of the immune infiltrate. Splenectomy experiments comfirmed the role of iTregs in tumor escape. Eventhough the number of tumor cells decreased, tumor growth could not be abrogated.

Conclusion We demonstrated that Tregs are recruited in the tumor microenvironment. Tregs limit the recruitement of CD4+ T‐cells in the eyes and are thought to inhibit their effector functions. The mechanisms by which Tregs are generated could be similar to ACAID, yet in the posterior chamber. Several escape mechanisms are responsible for tolerance toward the tumor in the eye.
Morphofunctional correlates in rhegmatogenous detachment of the retina
Authors: ZUEVA MV , NEROEV VV , GRINCHENKO MI , TSAPENKO IV , SARYGINA OI , RYABINA MV , TOLSTIK SI
Published: November 2009

Purpose To detect the selective reduction of retinal neurons' activity in retinal detachment (RD) of different duration and after the reattachment surgery (RS).

Methods We created earlier two protocols for 8‐30Hz flicker ERG testing in photopic (Ph) and scotopic (Sc) conditions using EP‐1000 TOMEY system. Standard and Ph/S flicker ERGs were examined in 9 healthy subjects and in 18 patients with rhegmatogenous RD (groups ≤1m, 1‐2m, >2m duration) in eyes with myopia before, 1w, 1m after the RS.

Results The comparing of Ph/Sc flicker and standard ERGs showed that in the RD group 1, the Sc system function was relatively more impaired than the Ph, confirming literature histological data about rods' alterations in the earlier period after RD. In RD<1m, ERGs at 8‐10Hz were more reduced than at higher frequencies. Our data showed the greater functional changes in photoreceptors for ≤1m, in cones and bipolar cells ‐ for 1‐2m, and moderate general alterations of retina function in the group 3 before the RS. After the RS, the general decrease of all ERGs was found, but the cone‐ERG a‐wave and Ph 8‐12Hz flicker ERGs, which amplitudes showed the moderate increase during the follow up. It was more typical for RD duration < 1m, and a recovery was the worst in 1‐2m RD.

Conclusion The flicker ERGs of broad frequency range seems to provide functional correlates of morphological alterations in RD, and may be useful in indirect estimation of retina recovery after the RS. In myopic eyes, even the earlier RS does not result in immediate recovering of retinal function. Earlier signs of restoration are characteristic only for the cone’s function, and they are more manifested after the RS for less than 1m RD.
Amniotic membrane transplantation (AMT): Implications for corneal wound healing
Authors: SAID DG , NUBILE M , HOPKINSON A , GRAY T , LOWE J , DUA HS
Published: November 2009

Purpose When transplanted as a graft AM is incorporated into the cornea. Our aim was to ascertain by immunohistology the fate of the incorporated membrane over time.

Methods Corneal buttons from 8 eyes treated by AMT for bullous keratopahty and subsequently had penetrating keratoplasty were examined by electron microscopy and by immunohistology with markers for keratocytes (CD34), fibroblasts (vimentin) and myofibroblasts (SMactin). Time from AMT to PK was between 2 to 32 months

Results Amnion tissue was covered with stratified corneal epithelium with well‐defined hemidesmosomes. At places a fluid cleft was seen between amnion and underlying Bowman’s zone. Transformed keratocytes/fibroblasts could be seen migrating from the anterior stroma, through breaks in the Bowman’s zone, into connective tissue of the amniotic membrane. Immunohistology showed that the cells populating amnion stroma were CD34 negative but positive for vimentin and smooth muscle actin. In 2 samples where corneal transplants were performed more than 1 year following AMT, some cells in the amniotic stroma showed CD34+ staining

Conclusion The amniotic basement membrane facilitates epithelial cell migration and adhesion. Corneal stromal keratocytes can migrate through breaks in Bownans zone, into the amniotic tissue thus integrating it with the host. Despite the presence of large fluid clefts between amniotic membrane and Bowman’s zone, the overlying epithelium remained compact. Repopulation of the amniotic stroma by corneal keratocytes allows for rebuilding of corneal stroma with an indication that over time they may revert to the resting keratocyte immunophenotype.
Clinical and microbiological features of acute bacterial conjunctivitis at the primary eye care unit in a hospital of central Italy
Authors: FRUSCHELLI M , MONTAGNANI F , PARADISO A , STOLZUOLI L , ZANCHI A , MOTOLESE I , MOTOLESE E
Published: November 2009

Purpose Aim of this study is to identify bacteria causing conjunctivitis in a central Italian area and to analyze their chemosusceptibility.

Methods From 2005 to 2006, 91 conjunctival swabs were collected from acute conjunctivitis cases who were examined in the primary eye care unit at the "S. Maria alle Scotte" Hospital in Siena. All swabs collected were screened for common bacteria and fungi. Susceptibility tests were performed on isolates.

Results Isolated bacteria were Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae for an amount of 86.2%. Overall, 100% of strains were susceptible to chloramphenicol and 96.6% to quinolones. Conversely, 20.7% of isolates were tetracycline‐resistant and, even if all Gram negative isolates were susceptible to gentamicin, more frequently isolated pneumococci are constitutively resistant.

Conclusion Acute “red eye” is one of the commonest reasons for consultation with primary eye care physicians; in the majority of cases an acute bacterial conjunctivitis is diagnosed, the pathogens most frequently responsible are Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus. Guidelines on the management of conjunctivitis recommend antibiotic routine use where bacterial infection is suspected. This study provides a support in rational choice of empiric therapy with distinct regional preferences in the topical agent to be used.
New optical device for functional studies of the optic nerve head
Authors: GEISER MH , TRUFFER F , KHAYI H , CHIQUET C
Published: November 2009

Purpose To develop a confocal ocular laser Doppler device for the recording of functional optic nerve head (ONH) blood flow responses to various physiological stimuli.

Methods The flowmeter consists of a self‐aligned confocal system, a fundus illumination (green light) and CCD based observation unit, a target fixation system and a CCD camera to observe the pupil. This CCD allows monitoring of the position of the probing laser beam at the pupil to insure constant entrance point in successive measurements of ONH blood flow. The Doppler signal is digitized and a dedicated software operating on a portable computer calculates the relative velocity, volume and flux of the red blood cells in the ONH microcirculation. Synchronization of theses parameters with the heart pulse allows determination of the flow pulsatility. Flicker stimulation of the macular area can be performed at 2 wavelengths. Three measurements were performed at rest in each of 29 normal subjects to determine the variability of ONH blood flow parameters. Preliminary responses of these parameters to the breathing of various gases were obtained.

Results Variability of blood flow obtained from 3 successive measurements from the same site ranged from 0.5 to 33% (mean 11%, n = 29). The breathing of carbogen (95% O2, 5% CO2) for 5 min by subjects with optimal target fixation induced an increase of ONH blood flow of 28 +/‐ 16 (sd) % (p = 0.03, n = 11) in accordance with previously published data.

Conclusion This new confocal device combined with monitoring of the entrance site of the laser beam at the pupil provides laser Doppler blood flow data at the ONH that show a variability that makes the device potentially useful for physiological and clinical investigations.
The future of neuroprotection in glaucoma therapeutics
Authors: WHEELER LA
Published: November 2009

Purpose Give an overview on the future of neuroprotection in light of the announcements concerning the memantine phase 3 clinical trial.

Methods Allergan recently unmasked the second memantine phase 3 clinical trial examining the efficacy and safety of oral memantine for the treatment of glaucoma.

Results While the study failed to meet its primary endpoint to sufficiently replicate the results of the first phase 3 trial; additional data analyses are ongoing. What have we learned about studing neuroprotection in this pioneering effort?

Conclusion An update on the status of the glutamate hypothesis and the implications for future neuroprotective therapies in glaucoma will be discussed.

Commercial interest
The lens response to daily in vivo exposures to UVR
Authors: GALICHANIN K , LI Y , MEYER L , LÖFGREN S , SÖDERBERG PG
Published: November 2009

Purpose Epidemiological data indicate correlation between life long exposure to ultraviolet radiation and cortical cataract. There is no experimental data on the effect of daily repeated in vivo exposures of the eye to UVR. This experiment was designed to verify whether the dose additivity for UVR exposures holds through periods of time up to 30 days.

Methods Eighty rats were conditioned to a rat restrainer five days prior to exposure. All animals were divided into 4 exposure period classes of 1, 3, 10 and 30 days of exposure to UVR. Each exposure period class of 20 animals was randomly divided into five cumulated UVR dose sub‐groups. Eighteen‐week‐old non‐anesthetized albino Sprague‐Dawley(SD) rats were exposed daily to UVR‐300 nm for 15 minutes. One week after the last exposure, animals were sacrificed. The lenses were extracted for macroscopic imaging of dark‐field anatomy and degree of cataract was quantified by measurement of intensity of forward lens light scattering. Maximum tolerable dose (MTD2.3:16), statistically defined standard for sensitivity for threshold for UVR cataract, was estimated for the periods of exposure and plotted with a linear regression as a function of days during which dose was accumulated.

Results All exposed lenses developed anterior subcapsular cataract with varying appearance depending on the period of days exposed to UVR. Small single doses of UVR accumulated to cause cataract during the periods up to 30 days. MTD2.3:16 for 1, 3, 10 and 30 days of repeated exposures was estimated to 4.7, 4.74, 4.8 and 6.0 kJ/m2, respectively.

Conclusion The tolerance to UVR‐B for 18 week old SD rat increases with increasing number of days being exposed. With lower single dose and longer duration for daily exposure the lens is more tolerant to UVR.
Cis‐urocanic acid, a novel anti‐inflammatory and cytoprotective drug, decreases effectively UVB‐induced IL‐6 secretion and cytotoxicity in human corneal and conjunctival epithelial cells in vitro
Authors: VIIRI J , RYHÄNEN T , PAIMELA T , LAIHIA J , LEINO L , SALMINEN A , KAARNIRANTA K
Published: November 2009

Purpose Urocanic acid (UCA) is a major UV‐absorbing chromophore in the epidermis and has been suggested to act as one of the initiators of UV‐induced immunosuppression. The anti‐inflammatory and cytoprotective effects of cis‐UCA were studied in human corneal and conjunctival epithelial cells in response to UVB‐irradiation in vitro.

Methods Human corneal epithelial cells (HCE‐2) and human conjunctival epithelial cells (HCEC) were exposed to 10, 100, 1000, and 5000 µg/ml concentrations of cis‐UCA (BioCis Pharma, Turku, Finland) with and without UVB‐radiation (4 x Philips TL 20W/12 lamps; total irradiation dose 153 mJ/cm2). Secreted interleukin‐6 (IL‐6) levels were analyzed with ELISA assay. Cell viability was measured by a colorimetric MTT (3‐(4,5‐dimethyldiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay.

Results The 100 µg/ml and 1000 µg/ml concentrations of cis‐UCA significantly suppressed IL‐6 secretion induced by UVB‐irradiation in both cell types. In addition, the same concentrations improved the viability of the UVB‐irradiated cells when analyzed by MTT assay. No significant alterations in IL‐6 expression levels or viability were observed in response to 10, 100, and 1000 µg/ml cis‐UCA only, while 5000 µg/ml cis‐UCA evoked cytotoxicity in both cell types.

Conclusion Our findings suggest that cis‐UCA is a promising novel drug to suppress UVB‐induced inflammation and cellular damage in human corneal and conjunctival epithelial cells.
Variability in short‐wavelength automated perimetry among peri‐ or postmenopausal women: a dependence on phyto‐oestrogen consumption?
Authors: Eisner Alvin , Demirel Shaban
Published: November 2009

Purpose:  To determine whether the hill of vision for Short‐Wavelength Automated Perimetry (SWAP) is shallower for women who consume phyto‐oestrogen‐rich foods than for women who do not.

Methods:  Visual field data were compared for two groups of healthy amenorrhoeic women 48–69 years‐old with normal vision and not using hormone replacement: (1) 24 subjects who reported consuming soy and/or flax products and (2) 20 subjects who reported not consuming these products. Two types of 24‐2 visual fields were measured: (1) Full Threshold SWAP and (2) a white‐on‐white (W/W) field obtained using a Swedish Interactive Threshold Algorithm (SITA Standard).

Results:  The reduction of SWAP sensitivity from the centre of the field (4 loci, mean eccentricity = 4.2°) to the periphery (20 loci, mean eccentricity = 21.9°) was less for soy/flax consumers than for nonconsumers, both with age‐referencing (mean difference = 1.7 dB, p = 0.018) and without (p = 0.012). Corresponding distinctions existed for the SWAP – W/W difference, and there was minimal effect for W/W fields alone. The peripheral age‐referenced SWAP sensitivities averaged 2.5 dB higher for consumers than nonconsumers (p = 0.022).

Conclusion:  The between‐group distinctions are consistent with the possibility (derived from the women’s health literature) that phyto‐oestrogens may counteract a decline of short‐wavelength‐sensitive cone‐mediated response among postmenopausal women. These results suggest another potential application for SWAP outside its original intended purpose as a glaucoma test. Future studies should assess whether phyto‐oestrogen consumption is most beneficial for women who are sufficiently young and/or not too far beyond menopause.
EDUCATIONAL ATTAINMENT DIFFERENCES BETWEEN POPULATION GROUPS IN SOUTH AFRICA AND THE TIMING AND NUMBER OF BIRTHS
Authors: Gustafsson Siv , Kalwij Adriaan , Worku Seble
Published: November 2009

From 1981 to 2005, the total fertility rate in South Africa has been reduced from an estimated level of 4.6 to 2.8 children per woman. The relative differences in the total fertility rate between population groups, however, remain large. Our empirical analysis of the determinants of the timing of births shows that better‐educated women schedule birth later and have fewer children. The differences in education between population groups account for a substantive part (up to 40%) of the differences in completed fertility between the population groups. Our findings suggest that educational reforms aimed at equal access to education, which benefit African women most, may not only improve the quality of life of women but also, through their impact on fertility behaviour, yield long‐run benefits, as they will have fewer children and more resources to invest in the next generation.
Internal bleaching of teeth: an analysis of 255 teeth
Authors: Abbott P , Heah SYS
Published: November 2009

Background:  Studies about bleaching have not analysed factors that affect the outcome. This aim of this study was to analyse the outcome of, and the factors associated with bleaching.

Methods:  Internal bleaching was done on 255 teeth in 203 patients. Colour was assessed pre‐operatively, postoperatively and at recalls. The cause and type of discolouration, number of applications, bleaching outcome, and colour stability were assessed.

Results:  The most common teeth were upper central (69 per cent) and lateral (20.4 per cent) incisors. Trauma was the most common cause (58.8 per cent), followed by previous dental treatment (23.9 per cent), pulp necrosis (13.7 per cent) and pulp canal calcification (3.6 per cent). Dark yellow and black teeth required more applications of bleach than light yellow and grey teeth. Colour modification was “good” (87.1 per cent) or “acceptable” (12.9 per cent). Teeth restored with glass ionomer cement/composite resin had good colour stability, but this was less predictable with other restorations. No teeth had external invasive resorption.

Conclusions:  Bleaching endodontically treated teeth was very predictable, especially for grey or light yellow discolourations. Glass ionomer cement/composite restorations were effective at preventing further discolouration. Patient age and tooth type did not affect treatment outcome and no cases of external invasive resorption were observed.
Localization of matrix metalloproteinases (MMPs‐2, 8, 9 and 20) in normal and carious dentine
Authors: Shimada Y , Ichinose S , Sadr A , Burrow MF , Tagami J
Published: November 2009

Background:  Dentine matrix metalloproteinases (MMPs) may participate in the destruction of dentine following demineralization by bacterial acids. This study investigated the localization of MMPs in carious dentine.

Methods:  Frozen sections of dentine caries were prepared without demineralization and immersed in monoclonal antibody against MMP‐2, ‐8, ‐9 and ‐20. The sections were labelled by IgG conjugated with gold colloidal particles, and observed under FE‐SEM. Labelling indexes (number of gold particles/μm2) of outer and inner carious dentine, respectively, with and without bacterial infection, were compared with that of normal dentine.

Results:  MMP‐2 was distributed in both carious and normal dentine; the level of MMP‐2 showed no significant difference among the outer caries, inner caries, and normal dentine. The labelling indexes of MMP‐8 and MMP‐9 both significantly decreased at the inner carious dentine compared with the level of normal dentine, but intensified again at the outer caries region. The labelling index of MMP‐20 was the highest at normal dentine.

Conclusions:  The localization of MMPs was visibly detected using immunogold labelling. The localization of MMP‐2 showed no significant difference among the three regions, while MMP‐8 and MMP‐9 showed significant reduction at the inner caries layer, and MMP‐20 reduced toward the outer caries.
Pre‐emptive ibuprofen arginate in third molar surgery: a double‐blind randomized controlled crossover clinical trial
Authors: Lau SL , Chow RLK , Yeung RWK , Samman N
Published: November 2009

Background:  This study evaluated the effectiveness of 400 mg ibuprofen arginate either as a pre‐emptive (PRE group) or postoperative (POST group) analgesic using a common dental pain model.

Methods:  A randomized double‐blind crossover clinical trial involving a series of consecutive patients admitted for bilateral third molar surgery. Results were analysed according to the self‐reported pain score and the pattern of rescue medication taken.

Results:  The mean pain score ranged from 0.73 to 1.60 for the PRE group and 0.47 to 1.41 for the POST group among 30 included subjects. The mean time point when first rescue medication taken was 7.3 hours and 8.3 hours postoperative, respectively. Nine patients (30 per cent) in the PRE group and 12 patients (40 per cent) in the POST group took no rescue medication. There was no statistically significant difference for all parameters between groups, while a majority (53 per cent) found the drug “good” to “excellent” in both groups.

Conclusions:  Ibuprofen arginate may be considered effective in reducing surgically induced moderate to severe pain when administered either pre‐operatively or postoperatively due to the reported relatively low pain score, less consumption of rescue medication, delayed onset of pain, good number of pain‐free patients and a high rating in the global assessment score.
Outcomes of dental implants placed in a surgical training programme
Authors: Smith LP , Ng M , Grubor D , Chandu A
Published: November 2009

Background:  This study evaluates surgical outcomes and survival rates of implants placed in a multidisciplinary implant teaching programme.

Methods:  A retrospective review of all implant surgery performed over a 6‐year period by accredited oral and maxillofacial surgery trainees at the Royal Dental Hospital of Melbourne was undertaken. Patients were reviewed for a minimum of 6 months post‐implant placement. Implant survival was defined as those implants which were not removed, were clinically integrated as assessed by torque testing and in an appropriate position to receive a subsequent prosthesis. Kaplan‐Meier analysis was used to assess overall survival and univariate factors affecting survival. Multivariate analysis used Cox proportional hazards models.

Results:  Over 6 years, 127 patients were treated. Follow‐up data were present for 105 patients with 236 implants placed. Survival of implants at 1 and 5 years was 94 per cent and 92.8 per cent, respectively. The only univariate and multivariate factor which affected implant survival was perioperative bone grafting. All failed implants were single stage. Other factors such as patient age, smoking status, implant site, anaesthetic type, immediate or delayed placement, implant length and diameter, and medical comorbidities did not significantly affect implant survival.

Conclusions:  A satisfactory implant survival rate was found in a tertiary teaching centre. Perioperative bone grafting significantly increased the risk of implant failure.
The Caries Management System: an evidence‐based preventive strategy for dental practitioners. Application for children and adolescents
Authors: Evans RW , Dennison PJ
Published: November 2009

The application of the Caries Management System (CMS) for children and adolescents follows the rationale underlying the application of the CMS for adults. Briefly, the CMS is a 10‐step, risk‐based, non‐invasive strategy to arrest and remineralize early lesions and to enhance caries primary prevention. The method for assessing each patient’s diet, plaque distribution, and signs of caries as shown in bitewing radiograph images, follows the protocols for adults. Protocols presented here relating to caries risk assessment, lesion diagnosis and management, and patient recall are specific for children and adolescents.

Fundamentally, non‐cavitated lesions in primary and especially permanent teeth are managed: (1) professionally by preservative non‐invasive means, including fluoride varnish and sealants; and (2) daily home toothbrushing using fluoride toothpaste where the aim is to arrest lesion progression so that restorations will not be necessary.

Monitoring of lesions through the review of clinical signs and bitewing images is the means for assessing caries activity. For those who fail to respond to advice to reduce cariogenic exposures and continue to develop new lesions at a steady or increased rate, a more intensified programme is required; their higher risk status is confirmed and treatment follows the corresponding protocol.
Efficient and Automated Analysis of Potentially Slender Structures
Authors: Jorabchi Kavous , Danczyk Joshua , Suresh Krishnan
Published: November 2009

Computer-based engineering analysis is now a routine process in virtual product design. However, when an object becomes slender, i.e., beam, plate, or shell like, 3D computational analysis is known to slowdown, or even lead to erroneous results. Indeed, the recommended method for analyzing slender objects is to replace them with equivalent lower-dimensional entities. However, explicit geometric reduction and replacement is impractical during automated product design, and requires specialized software tools. In this paper, we therefore develop an implicit dimensional reduction method, where the reduction is achieved through an algebraic process. The proposed reduction method is computationally efficient, and numerically equivalent to explicit geometric reduction. Moreover, standard off-the-shelf 3D finite element packages can be used to implement the proposed methodology. The efficacy of the proposed method is demonstrated within the context of shape optimization. Finally, the related problem of “automatic slenderness-detection” is also addressed briefly.
Large Nonlinear Responses of Spatially Nonhomogeneous Stochastic Shell Structures Under Nonstationary Random Excitations
Authors: To C. W. S.
Published: November 2009

A novel approach for determining large nonlinear responses of spatially homogeneous and nonhomogeneous stochastic shell structures under intensive transient excitations is presented. The intensive transient excitations are modeled as combinations of deterministic and nonstationary random excitations. The emphases are on (i) spatially nonhomogeneous and homogeneous stochastic shell structures with large spatial variations, (ii) large nonlinear responses with finite strains and finite rotations, (iii) intensive deterministic and nonstationary random disturbances, and (iv) the large responses of a specific spherical cap under intensive apex nonstationary random disturbance. The shell structures are approximated by the lower order mixed or hybrid strain based triangular shell finite elements developed earlier by the author and his associate. The novel approach consists of the stochastic central difference method, time coordinate transformation, and modified adaptive time schemes. Computed results of a temporally and spatially stochastic shell structure are presented. Computationally, the procedure is very efficient compared with those entirely or partially based on the Monte Carlo simulation, and it is free from the limitations associated with those employing the perturbation approximation techniques, such as the so-called stochastic finite element or probabilistic finite element method. The computed results obtained and those presented demonstrate that the approach is simple and easy to apply.
Prognostics of Machine Condition Using Energy Based Monitoring Index and Computational Intelligence
Authors: Samanta B. , Nataraj C.
Published: November 2009

A study is presented on applications of computational intelligence (CI) techniques for monitoring and prognostics of machinery conditions. The machine condition is assessed through an energy-based feature, termed as “energy index,” extracted from the vibration signals. The progression of the “monitoring index” is predicted using the CI techniques, namely, recursive neural network (RNN), adaptive neurofuzzy inference system (ANFIS), and support vector regression (SVR). The proposed procedures have been evaluated through benchmark data sets for one-step-ahead prediction. The prognostic effectiveness of the techniques has been illustrated through vibration data set of a helicopter drivetrain system gearbox. The prediction performance of SVR was better than RNN and ANFIS. The improved performance of SVR can be attributed to its inherently better generalization capability. The training time of SVR was substantially higher than RNN and ANFIS. The results are helpful in understanding the relationship of machine conditions, the corresponding indicating feature, the level of damage or degradation, and their progression.
Modeling of 2D and 3D Assemblies Taking Into Account Form Errors of Plane Surfaces
Authors: Samper Serge , Adragna Pierre-Antoine , Favreliere Hugues , Pillet Maurice
Published: November 2009

The tolerancing process links the virtual and the real worlds. From the former, tolerances define a variational geometrical language (geometric parameters). From the latter, there are values limiting those parameters. The beginning of a tolerancing process is in this duality. As high precision assemblies cannot be analyzed with the assumption that form errors are negligible, we propose to apply this process to assemblies with form errors through a new way of allowing to parameterize forms and solve their assemblies. The assembly process is calculated through a method of allowing to solve the 3D assemblies of pairs of surfaces having form errors using a static equilibrium. We have built a geometrical model based on the modal shapes of the ideal surface. We compute for the completely deterministic contact points between this pair of shapes according to a given assembly process. The solution gives an accurate evaluation of the assembly performance. Then we compare the results with or without taking into account the form errors. When we analyze a batch of assemblies, the problem is to compute for the nonconformity rate of a pilot production according to the functional requirements. We input probable errors of surfaces (position, orientation, and form) in our calculus and we evaluate the quality of the results compared with the functional requirements. The pilot production then can or cannot be validated.
Evaluating the Use of Digital Product Repositories to Enhance Product Dissection Activities in the Classroom
Authors: Devendorf Matt , Lewis Kemper , Simpson Timothy W. , Stone Robert B. , Regli William C.
Published: November 2009

Product dissection has been used successfully in a variety of ways to actively engage students in their learning; however, using product dissection in the classroom does have drawbacks: products, tools, and their upkeep can be costly, workspace and storage space can be difficult to obtain, and even the best crafted dissection assignments can end in chaos. Recent cyberinfrastructure initiatives seek to create ubiquitous, comprehensive, interactive, and functionally complete digital environments for research communities that consist of people, data, information, tools, and instruments. With product dissection as our unifying theme, we are applying cyberinfrastructure tools and technologies to undergraduate engineering education and assessing the impact of these tools on student learning. Specifically, the project combines product dissection activities at three universities with two digital design repositories CAD modeling and animation, video, and MediaWiki technology to enable cyberinfrastructure-based product dissection activities. Lessons learned from these efforts are presented from the students’ perspectives as well as that of the faculties in both engineering and computer science. The implications for implementing the developments on a national scale are discussed along with ongoing research.
An Improved Stiffness Model for Bolted Joints
Authors: Nassar Sayed A. , Abboud Antoine
Published: November 2009

An improved stiffness model is proposed for bolted joints made of similar and dissimilar plates. A novel approach is used to obtain an expression for the effective area used for determining the joint stiffness. More accurate estimate of the joint stiffness provides a more reliable prediction of the joint behavior both during its initial assembly, as well as under subsequently applied tensile loads in service. The effect of the grip length-to-diameter ratio, joint sizes, underhead contact radii ratio, hole clearance, and plate material/thickness ratio are investigated. Experimental data are used for determining the envelope angle α in the proposed analytical model. Finite element modeling is used for evaluating the accuracy of the proposed stiffness model.
Analysis, Design, and Control of an Omnidirectional Mobile Robot in Rough Terrain
Authors: Udengaard Martin , Iagnemma Karl
Published: November 2009

An omnidirectional mobile robot is able, kinematically, to move in any direction regardless of current pose. To date, nearly all designs and analyses of omnidirectional mobile robots have considered the case of motion on flat, smooth terrain. In this paper, an investigation of the design and control of an omnidirectional mobile robot for use in rough terrain is presented. Kinematic and geometric properties of the active split offset caster drive mechanism are investigated along with system and subsystem design guidelines. An optimization method is implemented to explore the design space. The use of this method results in a robot that has higher mobility than a robot designed using engineering judgment. A simple kinematic controller that considers the effects of terrain unevenness via an estimate of the wheel-terrain contact angles is also presented. It is shown in simulation that under the proposed control method, near-omnidirectional tracking performance is possible even in rough, uneven terrain.
Sensitivity Analysis of 3-RPR Planar Parallel Manipulators
Authors: Caro Stéphane , Binaud Nicolas , Wenger Philippe
Published: November 2009

This paper deals with the sensitivity analysis of 3-RPR planar parallel manipulators (PPMs). First, the sensitivity coefficients of the pose of the manipulator moving platform to variations in the geometric parameters and in the actuated variables are expressed algebraically. Moreover, two aggregate sensitivity indices are determined, one related to the orientation of the manipulator moving platform and another one related to its position. Then, a methodology is proposed to compare 3-RPR PPMs with regard to their dexterity, workspace size and sensitivity. Finally, the sensitivity of a 3-RPR PPM is analyzed in detail and four 3-RPR PPMs are compared as illustrative examples.