Radiology reports: assessment of a 5,000-word speech recognizer

A prototype 5,000-word recognizer for the generation of radiologic reports by voice entry was evaluated. The system had a capacity sufficient enough to include all radiologic examinations and all desired words in one lexicon. The lack of such a capacity had been identified as a major limitation of a 1,000-word system previously evaluated. Overall reliability in word recognition was 98%. The device may be widely applicable for use in any radiology practice.     

Prevalence of diabetes, hypertension and obesity at different levels of urbanisation in Vanuatu

OBJECTIVE: To determine the prevalence of non-communicable disease, specifically hypertension, diabetes and obesity, amongst populations at different levels of urbanisation in Vanuatu, and to relate the frequency of these conditions to the modernisation of way of life. DESIGN: A cross-sectional population-based comparative study of indicative cluster samples. SETTING: Republic of Vanuatu (south-west Pacific). A relatively undeveloped malarious island country. PARTICIPANTS: Adult (aged greater than or equal to 20 years) Melanesian ni-Vanuatu of both sexes. An occupation-based (civil servants) urban sample (n = 623) and area-based semi-rural (n = 349) and rural (n = 397) samples were employed. Response rates were 78%-92%. INTERVENTIONS: Cases detected were referred for assessment and treatment by local medical staff. MAIN OUTCOME MEASURES: Body mass index, triceps skinfold thickness, blood pressure, plasma glucose (fasting and 2 hours after 75 g glucose), plasma cholesterol and triglyceride levels. RESULTS: Modernity scores confirmed that the three locations represented different levels of acculturation. Prevalences of non-communicable disease were relatively low compared to other Pacific Island communities and industrialised countries. These conditions were nevertheless more common in the urban sample and least common in the rural sample. Non-communicable disease correlated positively with modernity scores and negatively with physical activity scores. Obesity correlated with blood pressure in the urban sample, and there was indirect evidence (urine sodium concentration) of higher salt intake with modernisation. Mean plasma cholesterol levels were lowest in the rural group. CONCLUSIONS: Prevalences of non-communicable disease are relatively low in Vanuatu, although rural-urban differentials are present, and likely to increase with continued development. The evidence presented is consistent with non-communicable disease being related to the modernisation of way of life; specifically: decreased exercise, obesity, and dietary change. Preventive activities should commence now.     

The effect of adhesives with various degrees of hydrophilicity on resin ceramic bond durability.

OBJECTIVES: To investigate the role of different acid surface-treatments and hydrophilic and hydrophobic bonding agents on resin ceramic bond durability. METHODS: Two resin cements, Tetric Flow and Nexus 2, were applied to CAD/CAM Cerec Vitablocs with six bonding strategies: (1) HF-etching and silanization, (2) HF-etching, silanization and application of a hydrophilic bonding agent, (3) HF-etching, silanization and application of a hydrophobic bonding agent, (4) H3PO4-treatment and silanization, (5) H3PO4-treatment, silanization and application of a hydrophilic bonding agent, and (6) H3PO4-treatment, silanization and application of a hydrophobic bonding agent. The hydrophilic agents were Syntac Single-Component and OptiBond Solo Plus. The hydrophobic agent was Visio Bond. After 1d water storage at 37 degrees C, 1 mm2 microbars were cut for the microtensile bond strength test (microTBS test). The microbars were subjected to a tensile load using a modified testing device immediately after trimming and after 7 and 28d water storage. The fractured specimens were examined with a stereomicroscope and scanning eslectron microscopy to determine the failure mode. RESULTS: HF-etching resulted in significantly higher microTBS than H3PO4-treatments (p < 0.001) The 1d microTBS with hydrophilic bonding agents was significantly higher than with the hydrophobic bonding agent (p < 0.001) but decreased with time after water storage ( p < 0.001) while bonds with the hydrophobic bonding agent remained stable. The percentages of adhesive failures after 1, 7, and 28d were 60, 86, and 94, respectively. SIGNIFICANCE: Bonding agents that contain hydrophilic monomers have a negative influence on the resin ceramic bond durability.     

Effect of conditioning time of self-etching primers on dentin bond strength of three adhesive resin cements.

OBJECTIVES: To evaluate the effect of increasing the dentin conditioning time with self-etching primers of different aggressiveness (pH) on the microtensile bond strength (muTBS) of three resin cements. MATERIALS AND METHODS: Pre-cured composite blocks were cemented with M-Bond, Bistite II DC, or Panavia F to flat occlusal dentin surfaces of human third molars, which were conditioned with M-Bond or Bistite II-primer for 30, 60 or 180 s or with Panavia-primer for 60 or 180 s. Each dentin-composite block assembly (four in each group) was longitudinally sectioned to obtain 1x1 mm microbars and tested for the muTBS. The morphology of the conditioned dentin surface and the hybrid layer was examined with SEM. RESULTS: Extending the primer conditioning time for Bistite II DC from 30 to 60 s significantly increased the muTBS (p<0.001) but did not further increase from 60 s to 180 s. For M-Bond there was only a significant increase from 30 to 180 s (p<0.05). For Panavia F the primer-conditioning time had no influence on the muTBS. SEM observations of conditioned dentin showed that the Bistite II DC and M-Bond self-etching primers with the lowest pH completely dissolved the dentin smear layer and plugs and formed well-defined hybrid layers. This was not found for Panavia F. SIGNIFICANCE: Dentin bond strength of resin cements using more aggressive self-etching primers is improved by increasing the conditioning time. To enable resin infiltration of highly filled resin cements, sufficient smear layer dissolution is necessary.     

Dental material artifacts on MR images

Magnetic resonance (MR) imaging of the head and neck is becoming an important aid in evaluating pathologic conditions of the brain, midface, and pharynx. Certain dental materials cause artifacts during MR imaging of the lower midface. These artifacts can obscure the normal anatomy. This study describes the degree of artifact production caused by various materials commonly used in dental restorations. Of the materials tested, those causing artifacts were made of stainless steel, such as orthodontic bands used for braces, and pins or posts that are commonly drilled into teeth to provide structure or stability before filling. Materials used as temporary or permanent fillings or crowns--such as amalgam, gold alloy, aluminum, microfilled resin, and polyvinyl acrylics--did not cause artifacts in the images.     

Tc-99m antifibrin Fab' fragments for imaging venous thrombi: evaluation in a canine model

An antifibrin antibody (T2G1s) Fab' fragment labeled with technetium-99m was tested for its ability to produce images of fresh thrombi in dogs. In gamma camera images, all thrombi were evident by 2-4 hours after injection. Mean thrombus-to-blood and thrombus-to-muscle ratios averaged 4.0 and 69 at four hours after injection and increased to 24 and 270, respectively, by 24 hours after injection. When compared with I-125 fibrinogen injected into the same dogs, Tc-99m-antifibrin Fab' had lower absolute uptake in thrombus but higher thrombus-to-blood ratios due to a faster rate of disappearance from the blood. The primary route of excretion was through the kidneys. Tc-99m-antifibrin Fab' was highly stable in vivo, with an average of 82% of the circulating radioactivity able to bind to fibrin at 4 hours after injection. When compared with an In-111-labeled Fab fragment of antifibrin antibody 59D8, thrombus-to-blood and thrombus-to-muscle ratios were slightly higher for the Tc-99m-labeled antibody, and the blood disappearance rate was slightly faster. The absolute uptake in thrombus, however, was not significantly different, and the thrombus was visualized at about the same time after injection. These studies suggest that Tc-99m T2G1s Fab' is a potential agent for detecting thrombi in a clinical setting.     

Migration of porcine endothelial and smooth muscle cells in response to platelet-associated factors

A NeuroProbe multiwell microchemotaxis assembly has been used to study the migration of porcine aortic endothelial and smooth muscle cells in vitro in response to serum factors. Whole pig serum was found to be chemokinetic for endothelial cells but not smooth muscle cells. Chemokinetic activity was higher in platelet-enriched, plasma-derived serum (PDS) than in platelet-free PDS. The supernatant from washed, lysed pig platelets also showed chemokinetic activity both for endothelial and smooth muscle cells. Chromatography on Sephadex G-200 showed that the lysate contained a number of activities that act independently on the two cell types. The chemokinetic activity that we have detected appears to be distinct from the chemotactic effect of platelet-derived growth factor and platelet factor 4 on the basis of insensitivity to protamine sulfate and molecular size. The role of these platelet factors in pathological changes in vascular structure is currently under study.