Publications by authors named "Lyberatos C"

In a case with splenomegaly of unknown origin and features of hypersplenism, an interstitial 9q deletion was identified as a sole clonal abnormality of bone marrow cells. The meaning of 9q deletion as a primary change, as well as its clinical significance, are considered.

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Liver uroporphyrinogen synthetase activity was measured in 45 mice, divided in three groups. The mice of the 1st group served as controls, those of the 2nd starved for 24 hours, while those of the 3rd were injected intraperitoneally with phenobarbital. The enzymic activity was found significantly (p less than 0.

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The effect of isonicotinic acid hydrazide (INH), a potent haem inhibitor, on globin chain synthesis was studied in reticulocytes from the following groups of patients: four non-thalassaemic patients (group i); five beta thalassaemia heterozygotes (group ii); three Hb S/beta thalassaemia heterozygotes (group iii); and two additional patients--one with homozygous beta thalassaemia and the other with thalassaemia intermedia (group iv). This was done to determine whether haem inhibitors depress alpha globin chain synthesis. The progressive increase of INH concentration (10-40 mmol l-1) in reticulocytes from a beta thalassaemia heterozygote resulted in a remarkable decrease of the alpha and beta chain synthesis, ranging from 80% to 97% and from 74% to 96% of control values, respectively, and in a gradual drop of alpha:beta ratio from 1.

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Some parameters of haem synthesis were estimated in 60 uraemic patients (30 non-dialysed, 30 dialysed) and in 30 matched controls. Serum delta-aminolaevulinic acid and erythrocyte coproporphyrin and protoprophyrin were found significantly higher in the non-dialysed uraemics than in the controls. Erythrocyte delta-aminolaevulinic acid dehydrase (ALA-D) activity was 498 +/- 174 mumol/h.

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delta-Aminolevulinic acid (delta-ALA) synthetase in mouse liver homogenate was significantly (p less than 0.001) higher in the presence of uremic compared with normal plasma, the ratio of the two values being 1.36 +/- 0.

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Liver delta-aminolevulinic acid synthetase activity was measured in mice living under abnormal atmospheric pressure conditions for 15 h. In the group living under low atmospheric pressure (51 kPa) the enzymic activity, either basal or induced by starvation and/or allylisopropylacetamide, was significantly (p less than 0.001) lower than that of the control group.

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The proteolytic degradation of labelled pyromycyl polypeptides was investigated in human intact erythroid cells derived from the bone marrow of eight non-thalassaemic patients and the peripheral blood of eleven thalassaemics (eight splenectomized beta thalassaemia heterozygotes and three sickle-cell beta thalassaemics). These abnormal polypeptides are rapidly degraded to soluble trichloroacetic-acid (TCA) fragments with a half-life of 12 min both in bone marrow and peripheral blood. This comes very close to the half-life reported for the puromycyl peptide degradative system in rabbit reticulocytes (15 min).

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The haem pathway enzyme uroporphyrinogen-I-synthase (UPGS) was assayed in erythrocyte samples from twenty normal, twenty beta-thalassaemia heterozygotic and twenty beta-thalassaemia homozygotic subjects, after partial separation of the erythrocytes according to their age. UPGS erythrocyte enzyme concentration activity was significantly higher in the young than in the old erythrocytes of normal (66.5 +/- 11.

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The frequency of Y-positive lymphocytes in blood smears at delivery and during early infancy was assessed to determine the exact time at which it is similar to the frequency in adults. It was found that at day 0 of life the frequency of Y-chromatin-positive cells was 26.6 +/- 13.

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Globin chain synthesis was studied in reticulocytes and bone marrow erythroid precursors in four sickle beta-thalassaemic Greek patients. Significant globin chain imbalance was found in reticulocytes (alpha/gamma + beta A + beta S = 2.20 +/- SD 0.

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In 60 children with mental retardation of unknown etiology, the whole blood lead, as well as the activity of the red cell delta-aminolevulinic acid dehydratase (delta-ALAD), was measured. Thirty normal children and 30 with mental retardation of known etiology were used as controls. The lead values were found significantly higher in the study patients compared with both control groups (P less than 0.

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By use of isoelectric focusing in polyacrylamide gel rods we were able to detect traces of HbA (approx. 1%) as a sharp and discrete band. By overloading the gel considerable amounts of HbA (slightly contaminated with HbF) could be detected and isolated.

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In 20 iron deficient patients and 21 normal controls the activity of the enzyme delta-ALA dehydratase of erythrocytes was assayed. In addition the urine porphyrins and porphyrin precursor excretions were measured. It was found that in sideropenic patients the erythrocyte delta-ALA dehydratase activity was almost constantly higher than in normals; the difference of the mean values being statistically significant (p less than 0.

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A 62-year-old man with variegate porphyria is reported. This is the first case to be described in Greece. Apart from the common features of the disease this patient exhibited sensory loss of the syringomyelic type.

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One hundred non-obese and non-diabetic individuals, 50 men and 50 women, were submitted to oral glucose tolerance tests performed in the morning and in the afternoon on different days. Although great individual variations were noted in both sexes, in men the mean blood sugar (BS) values did not significantly differ between the two tests; in women, however, the mean values after glucose loading were significantly higher during the afternoon test. By dividing the test population into those aged 50 and below and those over 50 it was found that only the group of younger women showed significant differences between the two tests with higher mean BS values during the afternoon test.

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In 68 patients with homozygous beta-thalassaemia the excretion of porphyrins and porphyrin precursors in urine has been assayed. Though a definite excretion pattern has not been established, the majority of the thalassaemics excrete an increased amount of coproporphyrin and porphobilinogen. The results are compared to those published by other authors.

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In a series of 18 known and 14 possible carriers of haemophilia A the factor VIII-related antigen was assayed. Comparison of results with the biological activity of factor VIII detected correctly 17 of 18 known carriers. On the other hand the carrier state was detected in 8 of 14 possible carriers.

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