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Biomedical subjects

J Faber

Publications and source records attributed to J Faber.

At least 217 records · Page 12Linked to original sources
PubMed1977

Intravenous and peroral TRH stimulation in sporadic atoxic goitre.

Thyrotrophin releasing hormone (TRH) stimulation test with 200 microng iv was performed in 35 patients with atoxic sporadic goitre. In 23 patients with diffuse goitre 7 showed a lack of increase in serum thyrotrophin (TSH) at a significantly increased frequency compared to controls (P = 0.0028). In 4 patients with solitary nodules 2 showed no significant response to TRH (negative), while 3 of the 8 patients with multinodular goitres had negative TRH test. Only 6 of the 12 TRH negative patients also had non-suppressible 131I uptake following T3. No significant difference in age and thyroid parameters was found between the TRH negative and TRH positive patients. In 7 TRH negative patients the test was repeated with 400 microng TRH but all remained negative. Five of these patients were given TRH perorally 80 mg daily for 2 weeks resulting in a significant increase in serum T4 and T3. No detectable increase in TSH was found. The response to iv bovine TSH in 4 TRH negative patients was found to be normal, suggesting that there was normal thyroid sensitivity to TSH. Our findings suggest that patients with TRH negative atoxic goitre can release biological active TSH following prolonged TRH stimulation. The high frequency of a negative standard TRH test in atoxic goitre seems to diminish the diagnostic value of the standard TRH test.

Administration, Oral↗
PubMed1976

Positional information in the amphibian limb.

(1) The concept of positional information is applied to a large amount of data obtained previously in experiments on developing and regenerating amphibian limbs. Only the proximo-distal axis of the limb is considered. It is shown that the concept provides a simple, unitary hypothesis which satisfactorily accounts for the experimental data, and may moreover suggest meaningful new approaches. (2) It is suggested that the boundaries of the bipolar limb system lie in the girdle skeleton and at the distal end of the limb, respectively, and that it is the apical epidermis of the growing or regenerating limb which defines the distal boundary conditions. A relatively stable gradient of positional information is assumed to be set up in the mesoderm (or mesenchyme). It is further shown that the differentiated limb retains its positional information and upon amputation imparts it to the base of the blastema. (3) To explain an apparent discrepancy between the developing and the regenerating limb, it is proposed that dedifferentiation of mesodermal limb tissues upon amputation entails a change os positional value in the mesenchyme. Consequently, the amputation level does not once and for all specify the positional value at the proximal end of a mass of blastemal mesenchyme, particularly when the mesenchyme is transplanted in such a way that its linear size decreases (regression) or increases (furion of several blastemas).

Amphibians↗
PubMed1976

Thyroid hormone response to varying doses of TSH.

Fifty-five normal subjects were studied following intravenous injection of increasing doses of bovine thyrotropin (b-TSH) from 0.5 to 250 mU/kg. Serum triiodothyronine (T3) and thyroxine (T4) were measured 1, 2, 3 and 4 h after the TSH injection. Dose-related increments in serum T3 and T4 were demonstrated with doses of b-TSH = 2.5 mU/kg and a maximum response was obtained after approximately 100 mU/kg. The fractional increase in serum T3 was greater than in serum T4, but the ratio between the increase in serum T4 and serum T4 and serum T3 (21.3/l ng/ng) was independent of the dose of b-TSH and time after TSH stimulation. The T3 response was reproducible and unaffected by sex and age.

Adolescent↗
PubMed1975

Correlation of spike intervals and amplitudes in hypersynchronous EEG episodes in rat with cobalt focus.

EEG activity was recorded from rats with chronic cobalt foci and implanted electrodes. Within this activity, hypersynchronous rhythmic spike episodes (and those of waves) of mean frequency of 8-9/sec were studied. The spike amplitude-interval relationship was assessed, using correlation analysis method. A positive correlation of an exponential nature was found to be growing in line with temporal development of episode.

Animals↗
PubMed1975

Factor analysis of EEG in healthy and diseased subjects.

Factor analysis was applied to EEG recordings of healthy and diseased subjects to be analyzed by an "on line" broad-band frequency analyser. Differences between the healthy and the diseased as to the number of given factors were established by means of the Lawly test. Up to 6 factors were determined for patients, up to 3 for the healthy. On medication, the number of factors rose in the delta and beta bands, remaining unchanged in the alpha band dropping the theta band. The patients manifested a sort of interindividual uniformity and intraindividual simplification. Except for different sites of pathological foci, the patients' EEG recordings were more like each other than those of healthy subjects. The latter might have undergone a similar process on medication. This enabled to establish more factors in the patients, moreover in such a way as to expose some general laws of cortical electric activity, such as unified cortical activity despite its various facets, hemispheral specificity, and finally also a relative autonomy of the frontal lobes.

Adolescent↗