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Biomedical subjects

H Wiese

Publications and source records attributed to H Wiese.

31 records · Page 2Linked to original sources
PubMed1986

[Image analysis in hip sonography. Classification criteria].

Based on 5000 ultrasound studies of infantile hips, Graf's classification and diagnostic criteria are reviewed with regard to their ability to discriminate between normal and pathological conditions. Additional criteria (delta angle and vector line) are presented, and the results compared. The proposed approach via visual analysis is explained as a flow chart. The consequences of the methodical limitations for use as a screening procedure are discussed.

Hip Dislocation, Congenital↗
PubMed1986

[Value of angle measurements in hip sonography. Methodological and technical analysis].

The Graf classification of sonographic hip-studies is based upon angle-measurements. 167 patients have been examined and evaluated in a double-blind study of the reproducibility of these measurements and the resulting classification. The resulting ranges for the different types were compared with the values given by Graf. The influence of the investigator, the interpreter and of the chosen section plane were analysed and compared with the difference in classifying based upon visual impression. The global impression of the operator proves to be the most reliable basis for interpreting the ultrasound study (variation of 6%), while the measured angle beta (+/- 35% deviation) seems not to be as useful.

Child, Preschool↗
PubMed1983

[Computer tomographic densitometry of primary liver tumors].

The dynamic computed tomography (CT) densitometry is defined as the combination of rapid bolus injection of urographic contrast medium and timed sequential computed tomography scan permitting recognition of different patterns of enhancement. The results of this method on fifty patients with histologically proofed hepatic tumors (focal nodular hyperplasia n = 12, cavernous hemangioma n = 13, liver cell carcinoma in cirrhotic liver n = 10, primary liver cell carcinoma n = 6, bile duct carcinoma n = 4, others n = 5) are demonstrated. CT-densitometry offers valuable aid for the differential diagnosis of focal liver lesions, i.e. cavernous hemangioma, focal nodular hyperplasia of the liver.

Adenoma, Bile Duct↗
PubMed1983

Compensation of the low-pass filter properties of the current measuring internode in potential-clamped myelinated nerve fibres.

The bandwidth of membrane current measurements in potential-clamped Ranvier nodes is limited by the low-pass filter properties of the internodes. If about 35% of the current measuring internode is grounded via an additional electrode, the bandwidth of this internode increases by a factor of about 40. Consequently, in potential clamp experiments the measured time course of the early ionic currents changes markedly, while the duration of the capacity current is shortened.

Animals↗
PubMed1983

On the capacity current in myelinated nerve fibres.

Different equivalent circuits are presented to describe the capacity current, Ic, of potential-clamped Ranvier nodes. The corresponding transfer functions are discussed in examining the influence of the involved parameters on size and time course of Ic. The following results were obtained: i. The duration and the amplitude of Ic increased with increasing membrane capacity. ii. The amplitude of Ic increased with increasing gain or decreasing time constant of the clamp amplifier while its duration was shortened. iii. Similar effects were seen with decreasing resistance in series with the nodal membrane. iv. Qualitatively identical but stronger effects were seen with increasing bandwidth of the current measuring internode. Measurements were carried out under experimental conditions close to the calculated ones. They resembled the calculated curves satisfactorily.

Amplifiers, Electronic↗
PubMed1979

Inverse relationship between fluoride and cancer in mouth and throat?

For all the 121 municipalities in Southern Norway where 60% or more of the inhabitants get water from registered water supplies, the municipal average concentration of natural fluoride in the water has been determined and the municipalities divided into three groups with fluoride level 0--0.05 mg/1, 0.06--0.10 mg/1, and 0.11--0.50 mg/1, respectively. The average, age-adjusted municipal mortality rate of cancer in the mouth and throat was then determined for each of these groups by sex. The resulting figures show that the mortality rate declines for both sexes with increasing fluoride level: For males from 4.7 deaths per 100 000 per year on the low fluoride level, to 3.9 deaths per 100 000 per year on the medium fluoride level, and to 3.1 deaths per 100 000 per year on the high fluoride level. For females the corresponding figures are 1.5, 1.3 and 0.5. Arguments to show that these figures are unbiased from different tobacco consumption habits, differences between urban and rural municipalities, and differences in population size are presented. Possible, explicatory models are discussed.

Female↗