Planimetric Analysis Research Articles

Summary of: Evaluation of in vivo denture plaque assessment methods

Background Measurement and assessment of denture plaque can provide valuable information regarding an individual's oral health status and assessment of new treatments or products. Current methods tend to rely on subjective indices or image analysis derived planimetric (area measurement) assessment of stained plaque on dentures. Plaque indices are most commonly used to assess plaque coverage without image capture. This is not ideal because the methods are subjective, examiner bias may occur, there is no reproducibility between studies, the methods have lower accuracy and sensitivity than image analysis, and there is no record. To the authors' knowledge, no standardised published method of denture plaque assessment is currently employed for product development and testing. Method In this study visual and planimetric plaque assessment methods were compared using reference dentures. In addition, an in vivo study compared these methods for evaluating denture cleanser efficacy. Results and conclusions The results show that blinded image scoring is more representative of the true plaque area coverage than 'live' denture scoring, detecting significant decreases in plaque coverage. Planimetric analysis provides a more sensitive and less subjective technique with greater differentiation between treatments. However, analysis is very time consuming. Thus, a number of recommendations are made regarding quantification of denture plaque for the assessment of cleanser products.

Evaluation of in vivo denture plaque assessment methods

Measurement and assessment of denture plaque can provide valuable information regarding an individual's oral health status and assessment of new treatments or products. Current methods tend to rely on subjective indices or image analysis derived planimetric (area measurement) assessment of stained plaque on dentures. Plaque indices are most commonly used to assess plaque coverage without image capture. This is not ideal because the methods are subjective, examiner bias may occur, there is no reproducibility between studies, the methods have lower accuracy and sensitivity than image analysis, and there is no record. To the authors' knowledge, no standardised published method of denture plaque assessment is currently employed for product development and testing. In this study visual and planimetric plaque assessment methods were compared using reference dentures. In addition, an in vivo study compared these methods for evaluating denture cleanser efficacy. The results show that blinded image scoring is more representative of the true plaque area coverage than 'live' denture scoring, detecting significant decreases in plaque coverage. Planimetric analysis provides a more sensitive and less subjective technique with greater differentiation between treatments. However, analysis is very time consuming. Thus, a number of recommendations are made regarding quantification of denture plaque for the assessment of cleanser products.

Presence of vulnerable coronary plaques in middle-aged individuals who suffered a brain death

Vulnerable plaques in coronary arteries are frequently found in individuals who died suddenly or due to an acute coronary syndrome. The prevalence and characteristics of these plaques in the middle-aged apparently healthy population are unknown. From a total of 652 hearts from transplant donors collected between 1996 and 2007, we selected those from apparently healthy individuals older than 40 years old who died of head trauma or stroke and had no evidence of prior vascular diseases. The coronary arteries were examined by serial sectioning at 3 mm intervals, and all areas of cross-sectional luminal narrowing were processed for histological, immunohistochemical, and morphometric studies. The atherosclerotic plaques were classified according to the American Heart Association Report. A total of 160 hearts were examined. Mean age was 50.3 +/- 5.8 years. Sixty-eight hearts had no advanced coronary atherosclerotic lesions (Type I, II, and III of the American Heart classification). In the remaining 92 hearts, we found 179 plaques considered high-risk lesions (American Heart Association Type IV, V, and VI). These plaques were more frequently found in males (P < 0.001) and in those with a higher heart weight (P < 0.001). The median (25th and 75th percentiles) vascular narrowing value using a planimetric analysis was 32% (21-53). No significant association with the cause of death was found (P = 0.09). High-risk coronary artery plaques not associated with significant vascular lumen reduction exist in 57% of patients who suffered a brain death with a mean of 1.11 lesions prone to rupture per individual.

MMP-13 Plays a Role in Keratinocyte Migration, Angiogenesis, and Contraction in Mouse Skin Wound Healing

Matrix metalloproteinases (MMPs) have been implicated in wound healing. To analyze the roles of MMP-9 and MMP-13 in wound healing, we generated full-thickness cutaneous wounds in MMP-9 knockout (KO), MMP-13 KO, MMP-9/13 double KO, and wild-type mice. Macroscopic wound closure was delayed in all of the KO mice, as compared with wild-type mice. The rate of re-epithelialization was significantly delayed in MMP-9 KO and MMP-13 KO mice and remarkably delayed in MMP-9/13 double KO mice, as compared with wild-type mice. Both MMP-9 and MMP-13 were expressed by the leading edges of epidermal cells in wild-type mice, and the migration of keratinocytes was suppressed by treatment with an MMP inhibitor or transfection of small interfering RNAs for MMP-9 or MMP-13, as compared with controls. The vascular density in wound granulation was significantly lower in both MMP-13 KO and MMP-9/13 double KO mice than in wild-type mice. Degradation of connective tissue growth factor in wound tissue was transiently prevented in MMP-13 KO mice. Morphometric analyses demonstrated a reduction in both wound contraction and myofibroblast formation in both MMP-13 KO and MMP-9/13 double KO mice. Proliferation and transforming growth factor-beta1-induced myofibroblast differentiation of dermal fibroblasts from MMP-13 KO mice were decreased, as compared with wild-type dermal fibroblasts. These data suggest that MMP-13 plays a role in keratinocyte migration, angiogenesis, and contraction in wound healing, while MMP-9 functions in keratinocyte migration.

Expression and location of intracellular tissue factor in atherosclerosis stable plaque of ApoE−/− mice

In the ApoE(-/-) mouse model of atherosclerosis (AS) stable plaque, the expression and location of intracellular tissue factor (TF) in the cellular components of AS stable plaque were investigated in order to explore the cellular mechanism of AS thrombosis. Pathological changes of the stable plaque were observed under a microscope. The expression of TF protein was examined in aortic stable plaque of mice by using immunohistochemistry. Color image planimetric system was used to analyze the histological components of the stable plaque and the TF distribution. Under the confocal microscope, the intracellular TF location in the stable plaque of mice was observed. The results showed the cellular area was the major part of stable plaque (67.36%+/-6.52%, P<0.01). The percentage of total area occupied by cellular area was significantly larger than atheromatous gruel and acellular area (P<0.01). Macrophages and smooth muscle cells (SMC) were major cells in the cellular area. The percentage of total area occupied by SMC was significantly larger than by macrophages (P<0.01). Multiple linear regression analysis showed there was a positive correlation between TF area and SMC area (r=0.616, P=0.008), and no correlation was found between TF area and macrophage area (r=0.437, P=0.08). Pictures of color image planimetric analysis of TF and SMC were merged to highlight areas with co-localization (yellow), it was concluded that the process could be a cell-mediated TF expression in the stable plaque. SMC may be the major source of TF in AS without plaque rupture.

Fixation of mesh to the peritoneum using a fibrin glue: investigations with a biomechanical model and an experimental laparoscopic porcine model

In recent years, the use of fibrin glue has become an established practice in several areas of surgical treatment. For example, fibrin glue is used increasingly as an alternative method for mesh fixation in hernia surgery, significantly helping to reduce the incidence of chronic pain. The experiments in this study were aimed at elucidating the extent to which tack- or suture-based permanent fixation can be replaced by fixation with fibrin glue for laparoscopic intraperitoneal repair of abdominal wall hernias. In an initial series of experiments conducted with a biomechanical model, the strength of the fibrin glue for fixation of lightweight mesh (TiMesh light) to muscle tissue was compared with its strength of fixation to the peritoneum. In a second series of experiments, mesh was laparoscopically implanted in an established porcine model. Fibrin glue was used for mesh fixation in six animals. Laparoscopic exploration and explantation of the meshes were conducted after 4 months. Planimetric analysis was performed to investigate adhesion and shrinkage of the mesh surface. The strength of fibrin glue for fixation of mesh to the peritoneum was significantly less than for its fixation to muscle tissue (11.86 N vs. 47.88 N; p = 0.001). Three of the implanted meshes were not completely integrated, and two of these were dislocated. On the average, adhesions were seen on 16% of the mesh surfaces. The mesh shrinkage rate was 24.2%. Mesh fixation alone to the undamaged peritoneum in the intraperitoneal region cannot be recommended because of the risk for dislocation. Additional fixation using sutures, tacks, or both is needed until the mesh material is completely integrated.

The use of composite meshes in laparoscopic repair of abdominal wall hernias: are there differences in biocompatibily?

In recent years, laparoscopic repair of abdominal wall hernias has become increasingly established in routine clinical practice thanks to the myriad advantages it confers. Apart from the risk of intestinal damage following adhesiolysis, to date no information is available on the best way of preventing the formation of new adhesions in the vicinity of the implanted meshes. Numerous experimental investigations, mainly conducted on an open small-animal model, have demonstrated the advantages of coating meshes, inter alia with absorbable materials, compared with uncoated polypropylene meshes. In our established laparoscopic porcine model we set about investigating three of these meshes, which are already available on the market. In total, 18 domestic pigs underwent laparoscopic surgery and three different composite meshes were tested in each case on six animals (Dynamesh IPOM, Proceed, Parietene Composite). At 4 months, postmortem diagnostic laparoscopy was carried out, followed by full-wall excision of the specimens. Planimetric analysis was conducted to investigate the size of the entire surface area and the extent of adhesions. Histological investigations were performed on five sections for each specimen. These focused on the partial volumes of inflammatory cells, the proliferation marker Ki67, apoptotic index, inflammatory cell marker CD68 and transforming growth factor beta (TGF-beta) as a marker of the extracellular matrix. A similar value of 14% was obtained for shrinkage of Dynamesh IPOM and Parietene Composite, while Proceed showed a 25% reduction in its surface area. Markedly lower values of 12.8% were obtained for Parietene Composite in respect of adhesions to the greater omentum, compared with 31.7% for Proceed and 33.2% for Dynamesh IPOM (p = 0.01). Overall, Parietene Composite performed best in the histological and immunhistochemistry tests. On the whole, all composite meshes showed evidence of good biocompatibility. However, none of the coatings was completely able to prevent adhesions. Coating of polypropylene meshes with collagen appears to confer significant advantages compared with other coatings.

Intravitreal bevacizumab (Avastin®) in proliferative diabetic retinopathy

To evaluate the efficacy and safety of intravitreal bevacizumab in proliferative diabetic retinopathy (PDR) patients. This interventional case series study included 15 eyes of 10 patients with bilateral PDR: 13 eyes with severe PDR and active new vessels (NV) and two eyes with recurrent vitreous haemorrhages. Study eyes received a single intravitreal injection of 1.25 mg (0.05 ml) bevacizumab. All eyes were followed up for 3 months, and eight of them for 9 months. Reinjection was performed in three eyes 4-6 months after the first injection. Study eyes were evaluated by fluorescein angiography at baseline, 1, 3 and 9 months. Quantitative planimetric analysis (QPA) of NV area was measured before and after treatment. All eyes received or completed panretinal photocoagulation (PRP) 1 month after the first injection. As early as at 1 month, all study eyes had a regression (paired t-test, P = 0.01) of QPA-estimated NV area. The eyes with recurrent vitreous haemorrhages had clearing of bleeding. These early effects were maintained at 3 months for all eyes and tended to be stable at 9 months. The fast and measurable efficacy of bevacizumab allowed a subsequent complete and safe PRP. Intravitreal bevacizumab did not reveal any side-effects and was effective in the regression of NV areas and the resolution of vitreous haemorrhages. This approach is potentially useful in allowing (within a planned temporal window) a safe and efficient PRP to be performed while minimizing the risk of its complications.

Sustained (rh)VEGF165 release from a sprayed fibrin biomatrix induces angiogenesis, up‐regulation of endogenous VEGF‐R2, and reduces ischemic flap necrosis

This study investigated (1) the release of recombinant human vascular endothelial growth factor ([rh]VEGF(165)) from an in vitro fibrin matrix, (2) the effects of (rh)VEGF(165) released from an in vivo fibrin matrix on ischemic flap necrosis in the rat dorsal skin flap model, and (3) the effects of (rh)VEGF(165) released from an in vivo fibrin matrix on VEGF-R2 expression in transgenic VEGF-R2/luc mice. In vitro fibrin matrices were spiked with (rh)VEGF(165) and demonstrated (rh)VEGF(165) release over 88 hours with 66% recovery. Ischemic dorsal flaps were treated with a fibrin sealant (FS), FS spiked with (rh)VEGF(165), or left untreated. Flaps treated with FS spiked with (rh)VEGF(165) showed greater viability than controls as measured by planimetric analysis. Immunohistochemical analyses revealed stronger neovascularization than that exhibited by controls. Transgenic mice implanted with FS spiked with (rh)VEGF(165) had significant increases in VEGF-R2 expression relative to controls at days 5-13 after implantation. Conclusions drawn from this work are that (1) (rh)VEGF(165) is released from an in vitro fibrin matrix at clinically appropriate times, (2) (rh)VEGF(165) increases the viability of tissue flaps in vivo, and (3) (rh)VEGF(165) induces the expression of VEGF-R2 expression. This work demonstrates the clinical ability of sprayed FS to locally deliver growth factors to ischemic tissue of patients.

Is triploidy indisputably determinable in hybridogenetic hybrids by planimetric analyses of erythrocytes?

The size of amphibian erythrocytes is positively correlated to their DNA content. Therefore, planimetry of erythrocytes has long been used to determine ploidy levels in amphibians. In Rana esculenta. a hybrid originating from Rana ridibunda x Rana lessonae natural crosses, planimetric determination of erythrocyte size is used to distinguish diploid and triploid specimen. In the present study we performed planimetric analyses on the hybrid Rana grafi, comprising a second hybridogenetic system with its parental species Rana ridibunda and Rana perezi in southern parts of France. We found size differences of diploid and triploid erythrocytes to range between 26 and 33% in studies on adult R. esculenta and calculated a mean difference of 30%. Our results strongly support a significant influence of the factors snout-vent-length (SVL), geographic location, organic matter of substratum, and relative amount of oxygen on the erythrocyte size of these hybrids. Discriminant analyses proved a probability of approximately 30% to disaffiliate individuals in our data set and indicated that ploidy determinations on individuals will be most unprobable, if the SVL of individuals strongly staggers and the habitats differ in their environmental characteristics. Due to the found dependencies of the erythrocyte size to several factors we consider planimetric analysis for reasons of ploidy determination as unprobable and thus we favour more sophisticated techniques such as DNA-flowcytometry or karyotype analyses.

A de novo splice donor mutation in the thrombopoietin gene causes hereditary thrombocythemia in a Polish family

Hereditary thrombocythemia is an autosomal dominant disorder with clinical features resembling sporadic essential thrombocythemia. Germline mutations in families with hereditary thrombocythemia have been identified in the gene for thrombopoietin (TPHO) and its receptor, MPL. Here we characterized a THPO mutation in a hereditary thrombocythemia pedigree with 11 affected family members. Affected family members carry a G --> C transversion in the splice donor of intron 3 of THPO that co-segregated with thrombocytosis within the pedigree. We previously described the identical mutation in a Dutch family with hereditary thrombocythemia. Haplotype analysis using single nucleotide polymorphisms surrounding the mutation indicated that the mutations arose independently in the two families. MPL protein levels, but not mRNA levels, were low in platelets from affected family members. Bone marrow histology showed features compatible with those of essential thrombocythemia, but the megakaryocytes were unusually compact, as assessed by planimetric analysis. Impaired microcirculation resulting in brief episodes of fainting and dizziness that responded well to aspirin were the predominant clinical features in a total of 23 affected family members studied. Disease onset is earlier in patients with hereditary thrombocythemia than in those with essential thrombocythemia, but the frequencies of thrombotic, vascular and hemorrhagic events are similar in the two groups. A mutation in THPO occurred de novo in the same position as in a previously described family with hereditary thrombocythemia. Patients with this mutation have elevated serum levels of thrombopoietin and a phenotype that responds to aspirin and does not require cytoreductive treatment.

Control of Pseudomonas aeruginosa Skin Infections in Mice Is Mast Cell-Dependent

Mast cells (MCs) have recently been shown to be essential for the elicitation of efficient immune responses in murine sepsis. To explore whether MCs also contribute to the control of bacterial skin infections, we studied skin lesions induced by Pseudomonas aeruginosa (PA) in genetically MC-deficient Kit(W)/Kit(W-v) mice, normal Kit(+/+) mice, and MC-reconstituted Kit(W)/Kit(W-v) mice. PA injections resulted in strikingly (>2-fold) larger skin lesions in Kit(W)/Kit(W-v) mice than in Kit(+/+) mice, which exhibited pronounced MC degranulation at infection sites. In addition, neutrophil recruitment following PA injections and bacterial clearance from sites of infection was significantly impaired in Kit(W)/Kit(W-v) mice compared with Kit(+/+) mice. Notably, the adoptive transfer of MCs to the skin of Kit(W)/Kit(W-v) mice before PA infection resulted in normal neutrophil accumulation as well as skin lesions comparable with those in Kit(+/+) mice in both bacterial burden and size. These findings demonstrate for the first time that activated MCs are crucial for the induction of protective innate immune responses to bacterial skin infections.

Fructose-Fed Rat Hearts are Protected Against Ischemia-Reperfusion Injury

High fructose-fed (HFF) rat model is known to develop the insulin-resistant syndrome with a very similar metabolic profile to the human X syndrome. Such metabolic modifications have been associated with a high incidence of cardiovascular disease. The role of free radical attack in diabetes mellitus and its cardiovascular complications have been abundantly documented. The present study examined the susceptibility to myocardial ischemic injury and the involvement of free radical attack and/or protection in the metabolic disorders of high FF rats. Rats were divided into two experimental groups that received diet for 4 weeks: a control group (C, n=28) receiving a standard diet and a HFF group (FF, n=28), in which 58% of the total carbohydrate was fructose. The euglycemic clamp technique was performed to assess insulin resistance. For the ischemia-reperfusion procedure, rat hearts were isolated and perfused at constant pressure before they were subjected to a 30-min occlusion of the left coronary artery followed by 120 mins of reperfusion. Hemodynamic parameters were measured throughout the protocol. Infarct-to-risk ratio (I/R) was assessed at the end of the protocol by 2,3,4-triphenyltetrazolium chloride staining and planimetric analysis. Lipid peroxidation, antioxidant enzyme activity, level of vitamin E, and trace element status were measured in blood samples from both groups. Rats of the FF group developed an insulin resistance indicated by the glucose infusion rate, which was decreased by 47%. Infarct size was significantly reduced in rats from the FF group (19.9% +/- 6.6%) compared to rats from the control group (34.6% +/- 4.9%), and cardiac functional recovery at reperfusion was improved in the FF group. Lipid peroxidation and oxidative stress were higher in the FF group, as indicated by higher malonedialdehyde level, whereas plasma vitamin E/triacylglycerol ratio was also enhanced in this group. This study indicates that fructose feeding affords protection against in vitro ischemia-reperfusion injury, potentially implicating vitamin E.

Radiographic Characteristics Fail to Predict Clinical Course after Subdural Electrode Placement

Subdural arrays of grid and strip electrodes are frequently used in epilepsy patients to localize the seizure focus and determine the location of critical brain functions via stimulation mapping. Postoperatively, the majority of patients with implanted subdural electrodes develop subacute extra-axial collections (EACs). Although conservative management is appropriate in most of these cases, occasionally patients manifest neurological symptoms that may necessitate reoperation for collection evacuation. Currently, there is little information available regarding the range of EAC size and the potential correlation between EAC size and symptom development. To facilitate treatment decision-making in postoperative subdural electrode patients, we reviewed and compared the computed tomographic (CT) features of postelectrode placement EACs in asymptomatic and symptomatic patients. We retrospectively reviewed the medical records and CT scans of 22 consecutive patients who underwent craniotomy for placement of subdural grid and strip electrodes at Columbia University Medical Center. Medical records were reviewed for neurological complications from the time of grid placement until its removal. Each EAC was measured on CT for volume (% of total cranial volume), maximal thickness, and midline shift. One patient was excluded secondary to the development of an intracerebral hemorrhage. Thirteen of 21 patients remained asymptomatic or minimally symptomatic during their hospitalization, with only mild to moderate, intermittent, postoperative headaches. The remaining eight developed symptoms such as persistent and severe headache, transient motor deficit, or speech impairment. Two of these patients underwent reoperation for hematoma evacuation. EACs in asymptomatic patients had a mean volume, maximal thickness, and midline shift of 5.7%, 1.25 cm, and 0.33 cm, respectively. EACs in symptomatic patients had a mean volume, maximal thickness, and midline shift of 7.7%, 1.46 cm, and 0.5 cm, respectively. Differences between maximal thickness and midline shift did not approach statistical significance. Despite this, the difference between the mean volume of symptomatic and asymptomatic EACs was statistically significant (P = 0.04). The conventional methods of midline shift and maximal thickness for assessing EAC size did not adequately differentiate symptomatic and asymptomatic subdural electrode patients with EACs. Although total volume calculation using digital planimetric analysis demonstrated a statistically significant difference, we found no clear threshold volume that correlated with clinical course. Therefore, the appearance of EACs on CT scans is of limited use in predicting the development of symptoms and possible postoperative complications after subdural grid placement. Clinical judgment must guide management and determine the potential need for reoperation.

Comparison of ABC/2 Estimation Technique to Computer-Assisted Planimetric Analysis in Warfarin-Related Intracerebral Parenchymal Hemorrhage

The ABC/2 formula is a reliable estimation technique of intracerebral hematoma volume. However, oral anticoagulant therapy (OAT)-related intracerebral hemorrhage (ICH) compared with primary ICH is based on a different pathophysiological mechanism, and various shapes of hematomas are more likely to occur. Our objective was to validate the ABC/2 technique based on analyses of the hematoma shapes in OAT-related ICH. We reviewed the computed tomography scans of 83 patients with OAT-associated intraparenchymal ICH. Location was divided into deep, lobar, cerebellar, and brain stem hemorrhage. Shape of the ICH was divided into (A) round-to-ellipsoid, (B) irregular with frayed margins, and (C) multinodular to separated. The ABC/2 technique was compared with computer-assisted planimetric analyses with regard to hematoma site and shape. The mean hematoma volume was 40.83+/-3.9 cm3 (ABC/2) versus 36.6+/-3.5 cm3 (planimetric analysis). Bland-Altman plots suggested equivalence of both estimation techniques, especially for smaller ICH volumes. The most frequent location was a deep hemorrhage (54%), followed by lobar (21%), cerebellar (14%) and brain stem hemorrhage (11%). The most common shape was round-to-ellipsoid (44%), followed by irregular ICH (31%) and separated and multinodular shapes (25%). In the latter, ABC/2 formula significantly overestimated volume by +32.1% (round shapes by +6.7%; irregular shapes by +14.9%; P ANOVA <0.01). Variation of the denominator toward ABC/3 in cases of irregularly and separately shaped hematomas revealed more a precise volume estimation with a deviation of -10.3% in irregular and +5.6% in separately shaped hematomas. In patients with OAT-related ICH, >50% of bleedings are irregularly shaped. In these cases, hematoma volume is significantly overestimated by the ABC/2 formula. Modification of the denominator to 3 (ie, ABC/3) measured ICH volume more accurately in these patients potentially facilitating treatment decisions.

Discrimination of Glaucomatous Optic Neuropathy by Digital Stereoscopic Analysis

To evaluate the diagnostic power of a novel digital stereoscopic imaging system in the diagnosis of glaucomatous optic neuropathy. Prospective cross-sectional analysis of the diagnostic accuracy of digital stereoscopic optic disc analysis in the diagnosis of glaucomatous optic neuropathy exhibiting mild to moderate field loss. Fifty-two patients with open-angle glaucoma and 54 normal individuals were recruited. The presence of a reproducible visual field loss characteristic of glaucoma was used as the reference standard for the presence of glaucoma independent of the optic nerve head appearance. Patients were excluded if the optic disc, fundus, or visual field indicated other disease. One eye from each patient and individual was included in the study, the eye with the least field loss and a randomly designated normal eye, respectively. Simultaneous stereoscopic optic disc photography was performed on each specified eye. Three experienced observers viewed the resultant stereoscopic image of each nerve head using a Z screen, recorded a subjective clinical diagnosis, and undertook digital stereoscopic planimetry. Separate linear regression analysis was performed, post hoc, from the planimetric results for each observer of the logarithm of neuroretinal rim (NRR) against optic disc area derived from each normal eye. Eyes with NRR areas below the 95th prediction interval of the normal cohort were then classified as glaucomatous. Sensitivity and specificity for the detection of glaucomatous optic neuropathy. With subjective stereoscopic analysis, sensitivity for glaucoma detection among the 3 observers was 80.8%, 76.9%, and 90.4%, with respective specificities of 94.4%, 79.6%, and 79.6%. Regression analysis of the NRR in 30 degrees segments gave sensitivities between 69.2% and 80.8% and specificities between 83.3% and 90.7%. A combination of the subjective and quantitative analysis did not significantly improve discrimination. The subjective analysis of digital stereoscopic images provides a useful method for the discrimination of normal and glaucomatous optic nerves. Planimetric analysis does not significantly improve the diagnostic precision of this technique.

Measuring carotid artery stenosis

Five different calliper methods for assessing the degree of carotid artery stenosis and visual estimation ("eyeballing") of postmortem carotid arteriograms were compared with the planimetric gold standard of the area reduction at the site of the stenosis. During autopsy 53 carotid specimens were removed in toto from 31 neurological patients. Carotid arteries were ligated and redistended to a physiological degree for standardised three-plane arteriography. Afterwards, the entire specimen was filled with an embedding medium under the same conditions and sectioned. Slices at the site of stenoses were histologically processed. Computerised planimetric analysis of the lumen area reduction was performed and compared with the arteriographic findings. Arteriograms were evaluated by two independent observers by means of linear Common Carotid Artery (CC), the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and squared measurements (NASCET2, ECST2) after applying the pi r2 function. Further, three independent observers performed eyeballing of the degree of stenosis from the postmortem arteriographies. Planimetry was carried out in 29 internal carotid artery (ICA) and 17 common carotid artery (CCA) stenoses ranging from 8.5 to 100%. The smallest mean differences of the degree of stenosis in % between planimetry and arteriography were -0.5 and 0.6%. The narrowest 95 %-limits of agreement covered a range of +/-24.1 and 26.3% of stenoses, and the highest correlation coefficients were both 0.9 for the CC and ECST2 techniques, respectively. By eyeballing, the degree of stenosis was underestimated by 13.5 to 15.8% on average. The narrowest limits of agreement between two observers for eyeballing covered a range of 35%. Three-plane arteriography has only a moderate accuracy and reproducibility in detecting and measuring carotid artery stenosis independent of the technique of measurement used.

A study to assess the efficacy of a new detergent free, whitening dentifrice in vivo using QLF planimetric analysis

To determine the effects of a detergent-free, whitening dentifrice using an in vivo plaque regrowth model with the novel application of QLF as a planimetric analysis tool. A total of 20 subjects took part in a double blind, single-centre, crossover study in which slurry rinses were the only form of plaque control over a 5-day period. Following a washout and prophylaxis the subjects used 2 daily rinses in the absence of all other plaque control methods. Subjects returned to the clinic on the afternoon of day 5 when plaque was disclosed and assessed by the plaque index and area using both a photographic and novel fluorescent planimetric technique. A further 9-day washout was carried out and the rinse period repeated to ensure that each subject had used both experimental and comparator slurries. Twenty subjects completed the trial. The test product showed a significant inhibition of plaque re-growth (16.9%) compared with a fluoride-matched comparator using the Turesky index (P < 0.0001), the photographic planimetric technique (17.5%) (P < 0.0001) and the novel QLF technique (18.4%) (P < 0.0001). The results confirm that plaque inhibition capability of a detergent-free whitening dentifrice is at least as effective as a fluoride matched comparator. QLF is a promising tool for disclosed plaque quantification.

An in vivo efficacy study of a new detergent free whitening dentifrice

Objective To determine the effects of a detergent-free, whitening dentifrice using an in vivo plaque regrowth model with the novel application of QLF as a planimetric analysis tool. Method A total of 20 subjects took part in a double blind, single-centre, crossover study in which slurry rinses were the only form of plaque control over a 5-day period. Following a washout and prophylaxis the subjects used 2 daily rinses in the absence of all other plaque control methods. Subjects returned to the clinic on the afternoon of day 5 when plaque was disclosed and assessed by the plaque index and area using both a photographic and novel fluorescent planimetric technique. A further 9-day washout was carried out and the rinse period repeated to ensure that each subject had used both experimental and comparator slurries. Results Twenty subjects completed the trial. The test product showed a significant inhibition of plaque re-growth (16.9%) compared with a fluoride-matched comparator using the Turesky index (P < 0.0001), the photographic planimetric technique (17.5%) (P < 0.0001) and the novel QLF technique (18.4%) (P < 0.0001). Conclusion The results confirm that plaque inhibition capability of a detergent-free whitening dentifrice is at least as effective as a fluoride matched comparator. QLF is a promising tool for disclosed plaque quantification.

Studies on the differentiation pathway and growth characteristics of epithelial culture cells of the human prostate.

We established explant primary cultures in order to study the growth and hormone responsiveness, and the differentiation process of prostatic epithelial cells. Cell outgrowth was achieved from explant tissue by using a new DU145-cell-conditioned medium and special plastic coverslips. To define the present model, proliferation assays were tested by [3H]thymidine assay and planimetric analysis. Cells were analyzed using immunocytochemistry, light, phase contrast and electron microscopy, polymerase chain reaction, telomerase ELISA and immunoassay (PSA). Morphology and electron microscopy revealed typical epithelial differentiation. Immunocytochemistry showed the content of basal and secretory epithelial cells, endocrine paracrine cells and a high level of proliferation. With increasing culture time, mature epithelial differentiation (PSA) increases and the initial increase of alpha-smooth muscle actin (alpha-SMA) decreases again. After further passaging, alpha-SMA expression is no longer detected and PSA expression decreases. Furthermore, epithelial cells showed both androgen responsiveness and androgen receptor expression. These findings show the presence of epithelial cells in a process of differentiation with endocrine paracrine cells and a high level of proliferation. This model may maintain the cellular and functional properties more closely related to the human prostate and may provide a valuable tool for studying stem cells and differentiation characteristics.