Biomedical subjects

J Stiakakis

Publications and source records attributed to J Stiakakis.

4 recordsLinked to original sources

PubMed2002

Left side right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy or dysplasia, a heart muscle disease of unknown cause, is anatomically characterized by variable replacement of myocardial muscle with adipose or fibroadipose tissue. It is usually considered a selective disorder whereas concomitant left ventricular involvement has been noted in a few cases. Two cases of the disease with evidence of extensive left ventricular involvement at pathologic examination are described. Hearts from two patients who died suddenly showed extensive biventricular infiltration by fibrofatty tissue in the first case and exclusively in the wall of the left ventricle the localization of the fatty and fibrotic lesions. These findings might suggest that the various localizations of the fibroadipose tissue are rather different expressions of the same disease and it is preferable to be termed 'arrhythmogenic cardiomyopathy' as other studies also indicate.

Adult↗

PubMed1993

Expression of alpha-thymosins in human tissues in normal and abnormal growth.

Radioimmunoassays specific for the N and C termini of human prothymosin alpha and the N terminus of human parathymosin alpha were employed for the measurement of the levels of alpha-thymosins in human thymus, spleen, and liver during normal growth and intestine and breast in malignant growth. A differential expression of the two alpha-thymosins was observed in thymus (prothymosin alpha-rich) and liver (parathymosin alpha-rich). A decline in the levels of both alpha-thymosins was found with age, with prothymosin alpha in thymus showing the sharpest change (15- to 30-fold). The levels of both alpha-thymosins were higher in malignant tissues as compared with healthy ones. In breast cancer, in particular, the mean increase for prothymosin alpha and parathymosin alpha was 17.9- and 11.5-fold, respectively. The major crossreactive material was characterized in all cases as intact prothymosin alpha and parathymosin alpha. These results suggest an in vivo relationship of the expression of alpha-thymosins with the human tissue cell proliferation activity.

Adolescent↗

PubMed1990

Purification and characterization of L-dopa decarboxylase from human kidney.

L-dopa decarboxylase has been purified to homogeneity from post mortem removed human kidneys. Homogeneity was examined by polyacrylamide gel electrophoresis (PAGE) analysis both in the presence and absence of SDS. The enzyme has a molecular weight of 100,000 daltons estimated by gel filtration and 50,000 daltons determined after SDS-PAGE. Human L-dopa decarboxylase therefore is a dimer. Polyclonal antibodies produced against human L-dopa decarboxylase react with the 50,000 daltons enzyme subunit after immuno-blotting and also precipitates enzyme activity. Activity against L-dopa is partially inhibited by 5-hydroxytryptophan (5-HTP). The effect of various cations on L-dopa decarboxylase activity has also been tested.

Adolescent↗

PubMed1988

A radioimmunoassay for parathymosin alpha using antibodies to synthetic N-terminal peptide 1-30.

Antibodies against the N-terminus of rat parathymosin alpha have been raised in rabbits by conjugating parathymosin alpha (1-30) to hemocyanin. A radioimmunoassay for parathymosin alpha was established by utilizing antibodies against the above polypeptide and parathymosin alpha(1-12)[Tyr] as tracer. The useful range was 5-450 pmol for parathymosin alpha. An epitope was located in the amino acid sequence 1-12. The antiserum failed to crossreact with the same molar concentrations of the partly homologous thymosin alpha 1 or prothymosin alpha. With this radioimmunoassay, parathymosin alpha was isolated from calf thymus after separation from prothymosin alpha by reversed phase HPLC. Endogenous proteases did not appear to generate N-terminal fragments of parathymosin alpha in rat liver extracts in a similar fashion to that observed for prothymosin alpha. Parathymosin alpha has a ubiquitous distribution in the human tissues examined, with levels ranging from 93 (brain) to 1043 (liver) ng of parathymosin alpha(1-30) equivalents/g (wet weight).

Adult↗