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At least 235 records · Page 13Linked to original sources
PubMed2003

Effect of data compression on proximal caries detection: observer performance with DenOptix photostimulable phosphor images.

OBJECTIVES: To study the effect of lossy image compression on caries detection. Null hypothesis states no difference in caries detection efficacy among observers using original digital images versus images compressed at various rates of compression. METHODS: Digital images of 41 extracted posterior teeth were obtained with a storage phosphor DenOptix (Gendex DenOptix Imaging system) system. Images were exported in Tagged Image File Format (TIFF) and compressed with Joint Photographic Experts Group File Interchange Format (JFIF), as provided by the software of the imaging system. The compressions options JFIF100%, JFIF75% and JFIF50% resulted in reducing the image size to 1:2, 1:11 and 1:16, respectively. Eight observers evaluated the presence or absence of caries on a 5-point confidence scale. The actual caries status of each proximal surface was determined by ground section histology. Responses were evaluated by receiver operating characteristic (ROC) analysis. Areas under the curves (Az) were assessed using analysis of variance (ANOVA). RESULTS: The mean Az scores were 0.85 for original/uncompressed images, and 0.89 for JFIF100%, 0.88 for JFIF75% and 0.88 for JFIF50% images. These differences were not statistically significant (P = 0.26). Differences between observers were also not statistically significant (P = 0.12). CONCLUSIONS: JFIF compression at the level of 1:16 can be used without significant deterioration in diagnostic accuracy for proximal caries detection.

Analysis of Variance↗
PubMed2005

The sorption of hydrogen sulfide from hot syngas by metal oxides over supports.

Six 5 wt.% metal sorbents including Mn, Fe, Cu, Co, Ce and Zn supported on gamma-Al2O3, prepared by the incipient wetness impregnation method with calcination at 700 degrees C for 2 h, have been investigated for sorption of hydrogen sulfide in the temperature range of 500-700 degrees C. The sorption experiments were conducted in a fixed-bed reactor in terms of breakthrough curves and characterized by X-ray powder diffraction. The results reveal that the copper and manganese sorbents exhibit the best performance because they provide nearly 100% utilization, but the copper sorbent has a lower sulfur sorption capacity compared with the manganese sorbent. The zinc and cerium sorbents are not good candidates attributed to the vaporization of zinc and unexpected product for cerium. Effects of support materials on 5 wt.% manganese were also investigated by using gamma-Al2O3, SiO2 and TiO2 in this study. Five weight percent Mn/gamma-Al2O3 shows the best performance among support candidates. On the basis of XRPD and BET surface area analysis, TiO2 appears a huge loss in BET surface area associated with a significant formation of rutile form.

Adsorption↗
PubMed2004

Service quality as measured by service fit and mortality among public mental health system service recipients.

Service fit, defined as consistency between mental health services judged needed and services received was measured for a random sample of service recipients in a public mental health system (N = 6588). A variant of small area analysis was used to measure the relationship between catchment area mortality rates from natural causes, suicide, and medicolegal causes and area fit scores for a variety of services. We tested the theory-based hypothesis that service fit would predict interarea variations in mortality better than simple measures of amount of service prescribed and received. We also tested the hypothesis that, controlling for relevant demographic and clinical factors, fit would be protective for mortality from all causes. Findings supported the first hypothesis. With respect to the second, service fit for only certain services was protective. Housing and clubhouses services were particularly protective, suggesting the importance of services providing social support.

Adult↗
PubMed1991

[Obstruction of pancreatic ducts with a fibrin glue. Study after segmentary autotransplantation in dogs].

The effects of the main pancreatic duct with a fibrin sealant have been investigated on an experimental model of segmental pancreatic transplantation in the dog. Fourteen segmental pancreatic transplantations were performed. A cephalic pancreactectomy was performed during the same operating time. The main duct was obstructed with a fibrin sealant (Tissucol modified by addition of a solution of aprotinine concentrated at 10,000 KUI per mL). Biological follow-up consisted in: 1) Intravenous Glucose Tolerance Testing at Day 0 and Day 28 with glycaemia's integral calculus and K V Alues. 2) Measurements of glycaemia and serum amylase every three days from day 0 to day 28. Histological examination of the pancreatic tissue before and after transplantation involved a microscopy analysis reporting the degree of fibrosis and necrosis. The areas of the Langherans islets and of the fibrosis were calculated with informatic area analysis. The study was carried on non diabetic dogs at Day 28. The glycaemia's calculus of IVGTT were not significantly different before and after transplantation (p = 0.291). On the other hand, there was a significant difference of the K Values before and after transplantation (p = 0.006). Histology after transplantation revealed important lesions of fibrosis and normal or hypertropic Langherans islets in most cases. Pancreatic ducts presented with linings thickened with fibrosis. There was no fibrin sealant in the lumen. Obstruction of pancreatic ducts with a fibrin sealant induces an important fibrosis of the pancreatic exocrin tissue allowing the preservation of a satisfactory endocrine function. This technic may be used in clinical practice during the segmental pancreatic transplantations or after cephalic pancreatico-duodenectomy.

Amylases↗
PubMed1995

Components of small area variation in death rates: a method applied to data from Sweden.

STUDY OBJECTIVES: The study aimed to develop and evaluate a method for small area analysis of different non-random components of the variation in death rates. The method was applied to incidence and mortality data for selected malignant neoplasms in 26 administrative health areas in Sweden. DESIGN: Variation in mortality and incidence rates for malignant neoplasms of the trachea, bronchus, and lung; colon; rectum; and cervix uteri in the 26 health areas were analysed after standardisation for age. In addition, the systematic and random components of variance were estimated. The systematic component of variance in mortality was divided into two additive components-one component was dependent on the variation in the corresponding incidence rates and the other remained after adjustment for incidence. SETTING AND PARTICIPANT: All cases diagnosed between 1972 and 1983 and all deaths between 1974 and 1985 for selected malignant neoplasms in Swedish citizens and other residents in Sweden, aged between 0 and 64 years, were analysed. MAIN RESULTS: Much of the observed variation in mortality was explained by the estimated random variation. For malignant neoplasms of the trachea, bronchus, and lung the systematic variation in mortality was mainly explained by the variation in incidence. For cancer of the cervix uteri, alone, there was significant systematic variation of moderate magnitude that was not explained by the incidence rates. CONCLUSIONS: These methods made it possible to divide the observed variance in mortality into different components. Random effects and variance in incidence rates were found to be of great importance when analysing the variance in death rates between health areas. By studying different systematic components of variation it is possible to identify fields for in depth studies on the quality of prevention and treatment.

Adolescent↗
PubMedDate not supplied

[Excess mortality in an inner-city area: the case of Ciutat Vella in Barcelona].

The purpose of this study is to compare mortality indicators in the district of Ciutat Vella (the more socio-economically deprived in Barcelona) with the entire city, for the 1983-87 period. Crude death rates, as well as age, sex and cause-specific deaths rates were calculated from vital statistics data; life expectancy, years of potential life lost (YPLL), the Comparative Mortality Figure (CMF) and avoidable mortality rates were also computed. All indicators point out at an excess of mortality in Ciutat Vella, when compared to the whole city. Life expectancy was 73 years (4 years less than for Barcelona as a whole); infant mortality was 15.6 per 1,000 births (as opposed to 9 for Barcelona). The CMF was 129 (95% confidence interval: 126.2-131.8), while the YPLL ratio was 182.1 (95% confidence interval: 173.1-191.8), mainly attributed to excess mortality due to tuberculosis, cirrhosis and to homicides and drug-related deaths. The percentage of avoidable deaths was 9.5% in Ciutat Vella compared with 8.23% for Barcelona as a whole. These data confirm the need to actively pursue intervention programs to improve health in Ciutat Vella, although further small-area analysis at the level of neighbourhood and of health care areas would be advisable.

Age Factors↗
PubMed1995

Attachment site specificity and the tapeworm assemblage in the spiral intestine of the blue shark (Prionace glauca).

The parasite assemblage in the scroll-type spiral intestine of 24 specimens of the blue shark Prionace glauca collected off of Montauk, Long Island, New York was investigated. When opened with a longitudinal incision to the right of the ventral blood vessels, the internal mucosal spiral of the spiral intestine of the blue shark could be unrolled into a flat sheet of double-sided mucosal tissue. Attachment sites and parasite assemblages were studied on both sides of the sheet in 12 sharks and on either the inside or the outside of the sheet in 12 additional sharks. Assemblages within host individuals were composed of up to 4 species of tetraphyllidean cestodes including the onchobothriid Platybothrium auriculatum, and the phyllobothriids, Prosobothrium armigerum. Paraorygmatobothrium prionacis, and Anthobothrium laciniatum. Each individual shark hosted 1-4 tapeworm species (mean = 3.7 +/- 0.65). The 12 sharks in which both sides of the mucosal scroll were examined hosted 156-2,382 (mean = 929.1 +/- 818) individual tapeworms. The assemblage consisted of 4 core species. Sharks were not found to host all of the possible combinations of species in their assemblages; the most common combination (17 out of 24 individuals) was the occurrence of all 4 parasite species. A chi-square test revealed no evidence that the 4 species did not occur independently. Regression revealed a significant relationship between shark total length and spiral intestine area. Analysis of covariance (ANCOVA) revealed a significant difference between the surface areas of the 2 sides of the mucosal sheet when shark total length was taken into account.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1977

The extraction and partial characterization of proteins released by decalcification from calcified human aortic plaques.

Tissue from severely atherosclerotic human aortas was divided into heavily calcified (plaque) and less calcified (non-plaque) areas. After defatting and thorough extraction with neutral salt solutions, further proteinaceous material was released from plaque than non-plaque areas. Although organic phosphorous was associated with the EDTA-solubilized protein from both plaque and non-plaque areas, the phosphorous to protein ratio of extracts from plaque areas was 2 to 3 times that from non-plaque areas. Analysis of the major protein component of the extract of plaque areas indicated an acidic glyco-protein which appeared to be associated with an organic phosphorous moiety as well as cholesterol and cholesterol esters.

Amino Acids↗
PubMed2001

Performance of RVGui sensor and Kodak Ektaspeed Plus film for proximal caries detection.

OBJECTIVE: A high-resolution charge-coupled device was used to compare the diagnostic performances obtained with Trophy's new RVGui sensor and Kodak Ektaspeed Plus film with respect to caries detection. STUDY DESIGN: Three acquisition modes of the Trophy RVGui sensor were compared with Kodak Ektaspeed Plus film. Images of the proximal surfaces of 40 extracted posterior teeth were evaluated by 6 observers. The presence or absence of caries was scored by means of a 5-point confidence scale. The actual caries status of each surface was determined through ground-section histology. Responses were evaluated by means of receiver operating characteristic analysis. Areas under receiver operating characteristic curves (A(Z)) were assessed through analysis of variance. RESULTS: The mean A(Z) scores were 0.85 for film, 0.84 for the high-resolution caries mode, and 0.82 for both the low resolution caries mode and the high-resolution periodontal mode. These differences were not statistically significant (P =.70). The differences among observers also were not statistically significant (P =.23). CONCLUSION: The performance of the RVGui sensor in high- and low-resolution modes for proximal caries detection is comparable to that of Ektaspeed Plus film.

Analysis of Variance↗
PubMed1996

Magnetic resonance imaging of cerebrospinal fluid volume and the influence of body habitus and abdominal pressure.

BACKGROUND: Although the cerebrospinal fluid (CSF) is the pathway of anesthetic delivery and the diluent for neuraxially administered drugs, little is known about its volume, including variability among individuals, longitudinal distribution, or influence of body habitus. Models made to investigate subarachnoid anesthetic distribution lack valid dimensions. CSF volume was measured in volunteers, and the effect of obesity and abdominal compression on CSF volume was evaluated using magnetic resonance imaging. METHODS: Low thoracic and lumbosacral axial magnetic resonance images of 25 healthy volunteers were obtained at 8-mm intervals by fast spin-echo sequence, which highlights CSF. A repeat image series was performed in 15 subjects during external abdominal compression. In two subjects, images were obtained without compression for the entire vertebral column. Dural sac and spinal cord areas were determined in a blinded fashion for each image using video/digital analysis. Area of the sac minus area of the cord constituted area of CSF and roots ("CSF/root"); this area multiplied by 8 mm resulted in CSF/root volume per section. RESULTS: There is great interindividual variability in CSF/root volume. From the T11-T12 disc to the sacral terminus of the dural sac, the mean volume for all subjects is 49.9 +/- 12.1 ml (mean +/- SD; range 28.0-81.1 ml). This volume was significantly less in relatively obese subjects (42.9 +/- 9.5 ml) than in nonobese subjects (53.5 +/- 12.9 ml). Abdominal compression decreased CSF/root volume by 3.6 +/- 3.2 ml. Sections through intervertebral foramina showed the biggest decrease with abdominal compression, with a lesser change in sections with veins and no change in the absence of these anatomic features. Total vertebral CSF/root volume in two subjects was 94.84 and 120.01 ml, respectively. CONCLUSIONS: CSF volume is widely variable between individuals. The decreased CSF volume that results from increased abdominal pressure, such as with obesity or pregnancy, may produce more extensive neuraxial blockade through diminished dilution of anesthetic. The mechanism by which increased abdominal pressure decreases CSF volume is probably inward movement of soft tissue in the intervertebral foramen, which displaces CSF.

Abdomen↗
PubMed1987

Computer-aided volume measurement of choroidal melanomas.

Using a combination of conventional B-scan ultrasonography, standard video techniques, computer image digitization and area analysis, it is possible to measure the volume of choroidal melanomas by area calculation of successive ultrasound image slices, allowing the monitoring of such tumors. The design of a combined water-bath and linear tracking B-scan transducer is presented, together with a description of the instrumentation and computer software required. The results of volume measurements performed upon eye models demonstrated that melanomas of volume greater than 100 mm3 could be measured with an average error of 6%. The problems associated with linear calibration of the system from scan-head to analysed image, resolution of the digitised image, reproducibility of the measurements, sources of error and assumptions made in formulating the measurement procedure are discussed.

Adult↗
PubMed1995

Body-size estimation in anorexia nervosa.

The aim was to explore the body-image perception of a group of 20 hospitalised anorexic patients, aged 18 to 21 years, undergoing a period of treatment. The instrument used was the Askevold nonverbal perception test as modified by Allamani and colleagues in 1978 to assess perception of the dimensions of different parts of the body by exploiting the capacity to project them into space. The four parts were the head, the thoracic area, the abdominal area, and the pelvic area. Analysis of responses indicated that anorexic patients overestimated the abdominal and pelvic areas much more than the 20 members of the control group (50% vs 30%). The areas of the head and thorax were perceived almost in their real dimensions by the anorexic patients but were underestimated by the control group.

Adolescent↗
PubMed2001

Disparity of perfusion and glucose metabolism of epileptogenic zones in temporal lobe epilepsy demonstrated by SPM/SPAM analysis on 15O water PET, [18F]FDG-PET, and [99mTc]-HMPAO SPECT.

PURPOSE: To elucidate uncoupling of perfusion and metabolism and its significance in epilepsy, 15O water and 18F fluorodeoxyglucose (FDG) positron emission tomography (PET) and Tc-99m hexamethyl-propyleneamine-oxime (HMPAO) single-photon emission computed tomography (SPECT) were examined by SPM (statistical parametric mapping) and quantitation by using SPAM (statistical probabilistic anatomic map). METHODS: [15O]water and [18F]FDG-PET, and [99mTc]-HMPAO SPECT were performed in 25 patients (SPECT in 17 of 25) with medial temporal lobe epilepsy. For volume of interest (VOI) count analysis, the normalized counts using VOI based on SPAM templates of PET and SPECT were compared with those of the normal controls. Perfusion or metabolism was found abnormal if the Z score was >2 for each VOI. For SPM analysis, the differences between each patient's image and a group of normal control images (t statistic for p < 0.01) on a voxel-by-voxel basis were examined to find significant decreases in perfusion or metabolism. RESULTS: With SPAM VOI count analysis, areas of hypoperfusion were found in 13 patients in the epileptogenic temporal lobes by [15O]water PET and areas of hypometabolism in 21 patients by [18F]FDG-PET. With voxel-based SPM analysis, the epileptogenic zones were localized in 15 by [15O]water PET and in 23 patients by [18F]FDG-PET. The localization by [15O]water PET was concordant with that of [18F]FDG-PET. The areas of hypoperfusion on [15O]water PET were absent or smaller than the areas of hypometabolism on [18F]FDG-PET. Interictal [99mTc]-HMPAO SPECT revealed the hypoperfused zones in seven of 17 patients on visual assessment. CONCLUSIONS: SPAM VOI count and SPM analysis of [15O]water and [18F]FDG-PET and [99mTc]-HMPAO SPECT revealed that in the same patients, the areas of hypoperfusion were concordant with but smaller than the areas of hypometabolism. Discordance of perfusion and metabolic abnormalities represents an uncoupling of perfusion and metabolism in the epileptogenic zones, and this might explain the lower diagnostic accuracy of perfusion imaging in temporal lobe epilepsy.

Adolescent↗
PubMed1989

Serum triglycerides as an independent risk factor for death from coronary heart disease in middle-aged Norwegian men.

The relation between nonfasting serum triglycerides and death from coronary heart disease was studied in 37,546 men aged 35-49 years who were examined during 1972-1977 in four counties in Norway. During an average follow-up period of nine years, 369 deaths from coronary heart disease occurred. In univariate analysis, log(triglycerides) were a weak, but statistically significant predictor of coronary death in the age groups 40-44 and 45-49 years. Within-area analysis showed that a high triglyceride area represented no extreme. When other coronary risk factors were adjusted for, log(triglycerides) remained a significant independent predictor at ages 45-49 years and at higher levels of serum cholesterol. The predictive strength of serum cholesterol was largely the same whether log(triglycerides) were taken into account or not, whereas the predictive strength of log(triglycerides) depended on whether serum cholesterol was accounted for. The strength of coronary death prediction of the logarithm of serum triglycerides was hardly greater than might be explained by the fact that triglycerides are an indicator of the usual cholesterol level of the subject.

Adult↗
PubMed2000

Intra-urban differences in breast cancer mortality: a study from the city of Malmö in Sweden.

STUDY OBJECTIVE: To assess whether in an urban population stage at breast cancer diagnosis is related to area of living and to what extent intra-urban differences in breast cancer mortality are related to incidence respectively stage at diagnosis. DESIGN: National registries were used to identify cases. Mortality in 17 residential areas was studied in relation to incidence and stage distribution using linear regression analysis. Areas with high and low breast cancer mortality, incidence and proportion of stage II+ tumours at diagnosis were also compared in terms of their sociodemographic profile. SETTING: City of Malmö in southern Sweden. PATIENTS: The 1675 incident breast cancer cases and 448 deaths that occurred in women above 45 years of age in Malmö 1986-96. MAIN RESULTS: Average annual age standardised breast cancer mortality ranged between residential areas, from 35/10(5) to 107/10(5), p = 0.04. Mortality of breast cancer was not correlated to incidence, r = 0.22, p = 0.39. The ratio of stage II+/0-I cancer incidence varied between areas from 0.45 to 1.99 and was significantly correlated to breast cancer mortality, r = 0.53, p = 0.03. Areas with high proportion of stage II+ cancers and high mortality/incidence ratio were characterised by a high proportion of residentials receiving income support, being foreigners and current smokers. CONCLUSIONS: Within this urban population there were marked differences in breast cancer mortality between residential areas. Stage at diagnosis, but not incidence, contributed to the pattern of mortality. Areas with high proportion of stage II+ tumours differed unfavourably in several sociodemographic aspects from the city average.

Aged↗
PubMed1998

Choriocapillaris degeneration and related pathologic changes in human diabetic eyes.

OBJECTIVES: To measure the extent of choriocapillaris degeneration (CCD) in diabetic choroids and to study the association of CCD with choroidal neovascularization and pathologic changes in Bruch's membrane-like basal laminar deposits. MATERIALS AND METHODS: Human choroids from 10 postmortem subjects (diabetic, 5 [group 1]; nondiabetic, 5 [group 2]) were incubated for the histochemical demonstration of alkaline phosphatase and nonspecific esterase activities, permitting analysis of the choroidal vasculature and polymorphonuclear leukocytes, respectively. The tissue was then flat embedded and sectioned for structural analysis. Areas of CCD were measured in the flat perspective by computer-assisted image analysis and verified in cross-sections of flat-embedded tissue. RESULTS: The CCD in choroids from subjects with diabetes (group 1) appeared in 2 patterns: diffuse (partial loss of alkaline phosphatase activity in a poorly defined area, ie, degeneration of some capillary segments) and focal (complete degeneration of choriocapillaris or loss of alkaline phosphatase activity in a relatively well-defined area). The mean+/-SD percentage of the choroid with focal CCD in group 1 was 5.08%+/-1.13% of the total choroidal area vs 1. 16%+/-0.35% in group 2 (P<.001). Focal CCD in group 1 was more prominent in the posterior pole than in the peripheral choroid. Choroidal neovascularization was associated with some areas of diffuse CCD in group 1. Pathologic changes in Bruch's membrane-like basal laminar deposits were often associated with CCD; the thickness of the deposits was greater in group 1 than in group 2 and greater in areas with focal CCD than in areas with diffuse or no CCD. CONCLUSION: The percentage of choroid with focal CCD in group 1 choroids was more than 4-fold greater than that in nondiabetic choroids. The presence of CCD was related to basal laminar deposits and, in some cases, to choroidal neovascularization.

Aged↗
PubMed1988

Interaction of polymyxin B1 and polymyxin B1 nonapeptide with phosphatidic acid monolayer and bilayer membranes.

The interactions of the antibiotic polymyxin B1 and its enzymatic cleavage product polymyxin B1 nonapeptide with phosphatidic acid monolayers and with bilayer membranes were investigated. Temperature-dependent pressure-area analysis of the monolayer reveals a linear increase of the lipid mean molecular area in the liquid condensed state for polymyxin concentrations between 10(-8) and 4 x 10(-7) M. Depending on the surface pressure, the area increase amounts to 30-70 A2. A linear dependence was also observed in the liquid expanded state but saturation is reached already at 10(-7) M polymyxin. The adsorption of polymyxin to phosphatidic acid bilayers is also linear and of a Langmuir type. Saturation is reached at a 1:4 polymyxin/lipid molar ratio. Polymyxin induces a phase separation in phosphatidic acid monolayers which was concluded from the thermotropic phase transition curves. In agreement with earlier bilayer experiments a second lowered phase transition appears in the presence of polymyxin. These fluidized domains again exhibit a linear polymyxin uptake comparable to the one of the liquid expanded monolayer at a temperature, where the undisturbed lipid is still in the condensed state. Polymyxin nonapeptide also causes an expansion of phosphatidic acid monolayers but only by maximally 10 A2. The thermotropic phase transition of the monolayer is reduced and considerably broadened by the nonapeptide. In phosphatidic acid bilayers we observed a decrease of the lipid phase transition temperature by 24 degrees C. The lateral chain packing is considerably disturbed by the peptide part of polymyxin.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, Competitive↗