Biomedical subjects
Publications and source records attributed to P Fessas.
A case of carcinomatous monoarthritis involving the left knee due to carcinoma of the pancreas is described. Lythic lesions of the bones were noted and malignant cells in the synovial fluid have been detected. Needle biopsy of the affected knee did not reveal carcinomatous infiltration of the synovium. The value of the synovial fluid examination for malignant cells in such cases is pointed out.
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Prevention of thalassemia and hemoglobinopathies is the only solution to efficiently reduce the huge medical, social and economic impact of these diseases in countries where they occur in high frequencies. In Greece, a serious effort has been undertaken towards this goal over the last years. Prevention is carried out at various levels: ample public education, easy provision of the necessary laboratory tests for carrier identification and thorough counseling of the couples at risk. Availability of prenatal diagnosis has contributed significantly to the acceptance by the public of various screening programmes. To date, the experience of the Greek group for prenatal diagnosis totals 1088 cases (June 1977 to December 1982). The number of couples at risk seeking the test prior to having any children is steadily increasing (prospective counseling). The efficacy of the overall prevention programme in Greece is reflected by the fact that the number of babies with thalassemia major admitted for transfusion to the major Units of the country has decreased substantially in the last years. Routine method used for prenatal diagnosis is biosynthesis of hemoglobin in samples of placental blood drawn by fetoscopy. With increasing experience the procedure now is safe (less than 1% of obstetrical complications in the last year) and the prediction accurate (no false diagnoses in the recent years). However, it is anticipated that the conventional method will soon be replaced by studies of amniotic cell DNA, a procedure both safer and less traumatic, or by studies of trophoblast DNA, which will allow prenatal diagnosis at an earlier stage of pregnancy.
The HLA-A and B phenotypes of 42 Greek children with CDH were determined and compared to those of 400 controls. A significant deviation of the frequency of the antigen HLA-A1, (Pc less than 0.003) was noted. It is suggested that immunogenetic factors are contributing to the development of the disease.
Recent studies from this department have suggested that the level of 2,3-DPG may be determined in part by the volume of the erythrocyte; this conclusion was reached on the basis of the finding of significantly elevated values of 2,3-DPG in heterozygous beta-thalassemia, even in the absence of anemia. In order to test the role of microcytosis in the formation of 2,3-DPG levels, a study was undertaken on a different patient material characterized by microcytosis without anemia or hypoxia, namely on cases of polycythemia vera (PV) rendered microcytic through therapeutic venesection (or blood loss) and on appropriate controls. Five cases of untreated PV (mean HB 18.36 +/- 1.53 g/dl, mean MCV 94.4 +/- 3.9 fl) had 2,3-DPG levels slightly lower than normal controls (13.67 +/- 0,75 mumoles/g Hb vs 14.18 +/- 1.41 mumoles/g Hb). Six microcytic iron deficient PV's (mean Hb 17.42 +/- 2.34 g/dl, mean MCV 74.5 +/- 6.2 fl) had very significantly increased 2,3-DPG levels (17.73 +/- 1.75 mumoles/g Hb). Similar high levels were obtained in five cases venesected in the past and maintained with cytostasis (mean Hb 15.22 +/- 0.67 g/dl, MCV 82.5 +/- 7.5 fl, 2,3-DPG 17.04 +/- 2.44 mumoles/g Hb). A strong linear negative correlation was obtained between 2,3-DPG values and the MCV (r = -0.736, P less than 0.001). It is concluded that microcytosis of other etiology and not only of beta-thalassemia may also lead, per se, to increased levels of 2,3-DPG. The different levels of 2,3-DPG in PV undergoing venesection vs untreated patients may explain some discrepant reports on the behavior of this metabolite in PV.
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A new electrophoretically silent hemoglobin variant is described that produces the classical phenotype of beta thalassemic intermedia in association with beta thalassemia trait. This variant has the expression of a silent beta thalassemia trait. The abnormal hemoglobin was detected by acid-urea-Triton-acrylamide electrophoresis and further demonstrated by isoelectric focusing. The amount of the variant in carrier is approximately 30% of the total hemoglobin. No instability was found. Absence of hemoglobin A in the propositus blood facilitated structural studies. Peptides maps were normal but analysis of individual peptide spots showed an Ala leads to Ser substitution in the beta T3. This variant has been previously called Hb Knossos (beta 27 (B9) Ala leads to Ser).
The pattern of HLA antigens was studied in 68 Greek patients with otosclerosis with and without a family history of otosclerosis and in the members of seven families in which the disease occurs, and was compared with that of 400 unrelated control subjects. Fifty-six specific HLA antiserum samples were used to determine 27 HLA-A and B antigens with the two-stage standard National Institutes of Health assay. The results were modified as follows: There was a highly significant increase of the antigens HLA-A11, Bw35, and B14 only in the patients with family history. These findings, together with the observations from the family studies and the information of population epidemiology and HL distribution frequencies, indicate the possible role of HLA antigens in otosclerosis and corroborate the view that genetic factors are also involved.
In a Greek family three cases of beta-thalassaemia intermedia were diagnosed as resulting from the interaction of a typical high HbA2-beta-thalassaemia with an atypical (silent) beta-thalassaemia gene. Following electrophoresis of globins on an acid-urea-Triton-acrylamide system, an otherwise silent beta-like variant was revealed in the carriers of the atypical thalassaemia gene and in the intermediates; it amounted to 33% of the non-alpha chains in the former and to c. 75% in the latter. The provisional name Hb Knossos is suggested for this abnormality.
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The levels of 2,3-DPG and the value of P50 were determined in unselected, clinically healthy, typical beta-thalassemia heterozygotes and normal controls. Values of 2,3-DPG in the heterozygotes are significantly elevated compared to normals (when expressed per gram of hemoglobin or per volume of red cells) and much higher than their mild hemoglobin deficit would explain; they are elevated even in selected heterozygotes presenting normal hemoglobins levels. These 2,3-DPG values, when expressed per number of erythrocytes, are within normal limits. In parallel, oxygen affinity is lower, as the P50 value is displaced to the right by 2 mmHg above the normal mean, thus assuring adequate tissue oxygenation. The findings suggest that the high 2,3-DPG values of the beta-thalassemia heterozygotes are not determined solely by anemic hypoxia; it is more likely that the microcytic erythrocytosis of heterozygous beta-thalassemia is the cause of this increase. The resulting lower oxygen affinity leads to a decreased stimulation of erythropoiesis and hence to its regulation at lower hemoglobin levels. Accordingly we suggest that the beta-thalassemia trait is a pseudo-anemia, because it is unlikely that these heterozygotes are unable to reach normal hemoglobin values by increasing erythrocyte output.
Immunoreactive human Chorionic Gonadotropin (hCG) was measured in serum and urine extracts from patients with malignant disease using a radioimmunoassay that detects efficiently hCG and its betasubunit. Of the 70 patients examined, 12 (17.1%) were positive for hCG in serum and 31 44.3%) in urine. Eleven patients who were positive in serum were also positive in urine; 20 patients (28.6%) were positive only in urine. Sephadex G-100 chromatography of urine from two serum-negative and urine-positive patients showed that the hCG immunoreactive material in the urine of these patients was mostly a molecular species smaller than hCG and hCG-beta. The nature of this molecule(s) is unknown and is called here metabolite(s) "X" of hCG-beta. The urine of 2 patients who where positive for hCG in both serum and urine contained considerable amount of metabolite(s) "X" as well as the native hCG-beta subunit, which was present also in the serum of these 2 patients. The metabolite(s) "X" was also shown by chromatography in the urine of a pregnant woman. It is concluded that the ectopic production of hCG is found more than twice as frequently in urine as compared to when serum alone is examined. The urine of serum-negative tumor patients can be positive for hCG because of the presence in it of the metabolite(s) "X" of hCG-beta or hCG which presumably circulates in the blood of these patients at non-detectable levels.
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Intracellular proteolysis was studied in both thalassemic and normal reticulocytes. The main experiment comprised a short incubation of RBC with [3H] leucine, extensive washings, and further incubation in the presence of cold leucine and protein synthesis inhibitors. In the aliquots removed at various time intervals, the TCA-soluble radioactivity increased in contrast with the TCA-precipitable cpm, which decreased with no exception on prolonged incubation. Results were more pronounced when the initial incubation was carried out in the presence of a valine analog and were markedly inhibited when phenanthroline was added during the second phase of the experiment. Cell-free system gave similar results. "globin" containing analog residues were degraded easier than free alpha- and beta-globin chains; free alpha or beta Hb chains are not proteolysed. Thalassemic and normal reticulocytes did not show any significant differences. It is proposed that the thalassemic RBC contain efficient proteolytic mechanisms up to the end of their maturation, but these prove incapable of proteolysing the excess alpha chains completely. Chemical manipulations aiming to make those chains more digestible constitute another approach to the treatment of thalassemia.