Comparison of fibre optic transillumination with clinical and radiographic caries diagnosis

Fibre optic transillumination (FOTI) has been employed during the course of a 3-yr clinical dentifrice trial which initially involved 3003 children. At the initial examination, a subgroup of 813 13-yr-olds, and at the following annual visit, 2247 14-yr-olds, were examined using a 150 W lamp and 0.5 mm diameter probe. Routine clinical and radiographic examinations were performed separately. Compared to the clinical scores for anterior teeth, FOTI detected an additional 64% of interproximal lesions at the first visit while, for the larger number of children at the second visit, the increase in lesion detection level using FOTI was 37%. For the posterior teeth the comparable figure at the second examination was 92%. When FOTI data were compared to radiographic data for more than 52,000 posterior interproximal surfaces, FOTI could only detect 17% of radiographic Grade 2 lesions and 48% Grade 3 lesions. Thus any assumption that FOTI diagnoses may be a substitute for bitewing radiography appears premature.     

A study of lectin-binding to the water-insoluble proteins of the lens

Binding of lectins to the water-insoluble fractions from human, monkey and mouse lenses was investigated. Lectins bound to glycoproteins blotted from SDS-polyacrylamide gels onto nitrocellulose paper. Use of multiple lectins showed that glycoproteins with apparent molecular weights of about 120 000 and 90 000 were present in all species. These proteins were found in the urea-insoluble fraction. Multiple lectins also bound to two bands around 67 000 and 63 000 molecular weight in both human and monkey lens fractions as well as a urea-soluble band at about 140 000. A 35 000 MW glycoprotein containing N-acetyl-galactosamine and fucose sugars was present in the capsule-epithelium of monkey lenses but was not detected in cortical or nuclear fractions. Glycoproteins from normal and cataractous mice were identified using this new methodology and compared with previously published work using sodium borohydride labelling of glycoproteins. Because of the numerous glycoproteins that can be detected and the ability to assign sugar residues to individual proteins, the lectin-binding method is a powerful tool to investigate lens glycoproteins.     

THE INFLUENCE OF NITROGEN RETENTION UPON THE REGENERATION OF PLASMA PROTEINS

1. Because of the clinical observation that the capacity to form new plasma proteins is sometimes impaired in cases of nephritis (2), experiments were performed to determine whether the impaired function in the nephritic is related to nitrogen retention. 2. These experiments consisted of producing renal injury by injecting uranium nitrate into standard hypoproteinemic dogs and comparing the rate of blood plasma protein formation under these conditions of nitrogen retention with that in the uninjured dog. 3. Despite elevations in blood N.P.N. to more than ten times normal, no interference with plasma protein formation was observed. These elevations in N.P.N. affected principally the urea and undetermined fractions. 4. Neither elevation in N.P.N. nor proteinuria per se appears to have any effect upon plasma protein production. Possibly the deficient production of plasma proteins in the nephritic is related to a more general disturbance in metabolism in which the elevation in N.P.N. is secondary.     

RENEX: an expert system for the interpretation of 99mTc-MAG3 scans to detect renal obstruction.

A renal expert system (RENEX) has been developed to assist physicians detect renal obstruction in patients undergoing pre- and postfurosemide 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) scans. RENEX uses quantitative parameters extracted from the dynamic renal scan data and heuristic rules in the form of a knowledge base (KB) obtained from expert interpreters to conclude whether a kidney is obstructed. METHODS: Normal limits were established for 47 quantitative parameters extracted from the 99mTc-MAG3 scans of 100 potential renal donors. From these data the domain expert estimated 5 boundary conditions for each parameter: (i) definitely abnormal, (ii) probably abnormal, (iii) equivocal, (iv) probably normal, and (v) definitely normal. A sigmoid-type curve was then generated from these 5 boundary conditions, creating a parameter knowledge library used for converting the value of a prospective patient's individual quantitative parameters to a certainty factor (CF). Sixty heuristic rules were extracted from the domain expert to generate the KB for detecting obstruction. A forward-chaining inference engine was developed using the MYCIN combinatories (an approximation of Bayes theorem) to determine obstruction. A justification engine was implemented, which recorded the sequence of each rule that was fired and the current CF value of all input and output parameters at the time of instantiation to track and justify the logic of the conclusions. The entire system was fine tuned and tested using a pilot group of 32 patients (11 males, 21 females; mean age, 56.8 +/- 17.2 y; 63 kidneys) deemed by an expert panel to have 41 unobstructed kidneys, 13 obstructed kidneys,and 9 equivocal findings. RESULTS: RENEX agreed with the expert panel in 92% (12/13) of the obstructed kidneys, 93% (38/41) of the unobstructed kidneys, and 78% (7/9) of the kidneys interpreted as equivocal for obstructions. Processing time per patient was practically instantaneous using a 3.0-GHz personal computer programmed using interactive data language. CONCLUSION: We have developed a renal expert system for detecting renal obstruction using pre- and postfurosemide 99mTc-MAG3 renal scans, at a standardized expert level. These encouraging preliminary results warrant a prospective study in a large population of patients with and without renal obstruction to establish the diagnostic performance of this system.     

Genotype prevalence and risk factors for severe clinical adenovirus infection, United States 2004-2006.

BACKGROUND: Recently, epidemiological and clinical data have revealed important changes with regard to clinical adenovirus infection, including alterations in antigenic presentation, geographical distribution, and virulence of the virus. METHODS: In an effort to better understand the epidemiology of clinical adenovirus infection in the United States, we adopted a new molecular adenovirus typing technique to study clinical adenovirus isolates collected from 22 medical facilities over a 25-month period during 2004-2006. A hexon gene sequence typing method was used to characterize 2237 clinical adenovirus-positive specimens, comparing their sequences with those of the 51 currently recognized prototype human adenovirus strains. In a blinded comparison, this method performed well and was much faster than the classic serologic typing method. RESULTS: Among civilians, the most prevalent adenovirus types were types 3 (prevalence, 34.6%), 2 (24.3%), 1 (17.7%), and 5 (5.3%). Among military trainees, the most prevalent types were types 4 (prevalence, 92.8%), 3 (2.6%), and 21 (2.4%). CONCLUSIONS: For both populations, we observed a statistically significant increasing trend of adenovirus type 21 detection over time. Among adenovirus isolates recovered from specimens from civilians, 50% were associated with hospitalization, 19.6% with a chronic disease condition, 11% with a bone marrow or solid organ transplantation, 7.4% with intensive care unit stay, and 4.2% with a cancer diagnosis. Multivariable risk factor modeling for adenovirus disease severity found that age <7 years (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.4), chronic disease (OR, 3.6; 95% CI, 2.6-5.1), recent transplantation (OR, 2.7; 95% CI, 1.3-5.2), and adenovirus type 5 (OR, 2.7; 95% CI, 1.5-4.7) or type 21 infection (OR, 7.6; 95% CI, 2.6-22.3) increased the risk of severe disease.