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Biomedical subjects

G A Hahn

Publications and source records attributed to G A Hahn.

11 recordsLinked to original sources

New standardised texts for assessing reading performance in four European languages.

AIMS: To develop standardised texts for assessing reading speed during repeated measurements and across languages for normal subjects and low vision patients. METHODS: 10 texts were designed by linguistic experts in English, Finnish, French, and German. The texts were at the level of a sixth grade reading material (reading ages 10-12 years) and were matched for length (830 (plus or minus 2) characters) and syntactic complexity, according to the syntactic prediction locality theory of Gibson. 100 normally sighted native speaking volunteers aged 18-35 years (25 per language) read each text aloud in randomised order. The newly designed text battery was then applied to test the reading performance of 100 normally sighted native speaking volunteers aged 60-85 years (25 per language). RESULTS: Reading speed was not significantly different with at least seven texts in all four languages. The maximum reading speed difference between texts, in the same language was 6.8% (Finnish). Average reading speeds (SD) in characters per minute are, for the young observer group: English 1234 (147), Finnish 1263 (142), French 1214 (152), German 1126 (105). The group of older readers showed statistically significant lower average reading speeds: English 951 (97), Finnish 1014 (179), French 1131 (160), German 934 (117). CONCLUSION: The authors have developed a set of standardised, homogeneous, and comparable texts in four European languages (English, Finnish, French, German). These texts will be a valuable tool for measuring reading speed in international studies in the field of reading and low vision research.

Adolescent↗

Carbon dioxide laser surgery in treatment of condyloma.

During the past few years there has been a marked increase in the occurrence of condyloma. A variety of treatment methods, including mental suggestion, local 5-fluorouracil, podophyllum, electrosurgery, and cryotherapy, has been used with varying success. An experience in 47 patients, some of whom were pregnant, treated with the carbon dioxide laser is presented. The possible relationship to malignancy and tracheobronchial papillomatosis in children is discussed.

Adolescent↗

Use of fluorouracil-uracil combinations to study growth accompanied by insufficient deoxyribonucleic acid synthesis in Bacillus cereus.

5-Fluorouracil (FU) at a concentration of 16 muM almost totally inhibited deoxyribonucleic acid (DNA) synthesis and cell division by Bacillus cereus, whereas growth continued at an exponential rate (25% of control for at least 3 h). In cultures simultaneously given 160 muM uracil (U) along with the FU, DNA synthesis still stopped, but cell division continued for one generation at the control rate and at a much slower rate beyond that; in the meantime, cell mass continued to increase at an essentially normal rate. The cells in cultures treated with FU or FU plus U were elongated and contained about half of the control content of DNA, with one nuclear area per cell instead of two. Loss of cloning ability, unlike mass increase, was always correlated with the continuing inhibition of DNA synthesis, in either FU- or U plus FU-treated cultures.

Bacillus cereus↗

Usefulness of magnetic resonance imaging for the diagnosis of acute musculoskeletal infections in children.

A 30-month prospective study was conducted on 43 children who presented with clinical findings suggestive of acute hematogenous musculoskeletal infection. Magnetic resonance imaging (MRI) was found to be extremely sensitive (0.97) and specific (0.92) in helping to diagnose these infections, with only one false positive and one false negative study. Bone scans are more likely to yield false positive and negative examinations. MRI is particularly useful in difficult cases in which there are conflicting clinical data or infection involving the spine or pelvis. After MRI demonstrates the location of the disease process, histologic and/or bacteriologic confirmation of the etiology is still mandatory.

Acute Disease↗