Biomedical subjects

K Levin

Publications and source records attributed to K Levin.

At least 37 records · Page 2Linked to original sources

PubMed1977

Studies on replacement and suppressive dosages of 1-thyroxine.

Serum thyrotropin (TSH) levels were studied in 55 hypothyroid patients in order to determine adequate replacement and suppression dosages of 1-thyroxine (T4). In accordance with previous reports it was found that most patients had normal TSH levels and were clinically euthyroid at daily doses of 0.10-0.15 mg T4. None of the patients required a dose exceeding 0.20 mg. When the TSH levels normalized, serum thyroxine and serum triiodothyronine also fell to levels within their normal ranges. The effectiveness of various doses of T4 in suppressing the temporary rise in serum TSH concentration normally induced by thyrotropin-releasing hormone was examined in 57 patients treated with T4 for atoxic goitre or after subtotal surgical removal of such a goitre. The rise in TSH was not usually inhibited by a T4 dose of less than 0.20 mg, a finding which at least theoretically has implications for the adequate suppressive dose of T4.

Female↗

PubMed1977

Calorimetry, a time-honored technique with a potential in analytical work and cellular biology.

Different types of calorimeters are briefly reviewed, stressing those instruments likely to be of interest in the clinical chemistry laboratory. The unspecific nature of the measuring procedure is emphasized and various pitfalls likely to cause analytical errors are pointed out. Recent work is reviewed where calorimeters have been used as analytical tools for the determination of glucose, protein, enzymes, and other substances. The results generally compared favorably with those obtained by conventional analytical procedures. In recent reports the time per analysis has been brought down to 2 min, with sample volumes in the micro range. Valuable information on the coagulation process has been obtained by use of calorimetry. I also review studies showing that intact cellular elements such as human blood cells, bacteria, and spermatozoa can successfully be investigated with calorimetric techniques. In particular, studies on human blood cells stimulated with various agents appear to be able to give valuable diagnostic information. I believe that new designs of microcalorimeters have placed an easily handled tool at the disposal of the worker in a clinical laboratory and that use of this tool can contribute to the development of our discipline.

Bacterial Physiological Phenomena↗

PubMed1976

Studies on subclinical hypothyroidism with special reference to the serum lipid pattern.

Subclinical hypothyroidism is an example of the impact of technology on the concept of a disease. It denotes a condition in which laboratory findings, at least including a raised serum thyrotropin (s-TSH), indicate hypothyroidism in the absence of clinical signs or symptoms of this disease. One reason for attention to cases of subclinical hypothyroidism is the publication of reports, from the time before introduction of the s-TSH assay, that hypercholesterolaemia precedes other evidence of thyroid failure with attendant risks of ischaemic heart disease and other atherosclerotic manifestations. The present investigation, which concerned the lipid pattern in sublinical hypothyroiism, offered no support for such a concept of hypercholesterolaemia as a premonitory sign of hypothyroidism. Furthermore, no significant differences were found between the serum levels of cholesterol and triglycerides before and after the administration of a thyroxine dose, necessary to suppress the s-TSH into a normal range, in cases of sublinical hypothyroidism. Nor were there any changes during this therapy in body weight, ECG, or Hb levels, which represent important parameters often found to be abnormal in overt hypothyroidism. From a practical point of view, subclinical hypothyroidism probably can be regarded as a state in which reduction of thyroid activity has been compensated by an increased s-TSH secretion to maintain a clinically euthyroid state. When no goitre is found, the rationale of treatment of this condition remains to be proved.

Cholesterol↗

PubMed1974