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Biomedical subjects

M Kalmanti

Publications and source records attributed to M Kalmanti.

At least 55 records · Page 3Linked to original sources
PubMed1994

Trends and geographical distribution of childhood leukemia in Greece in relation to the Chernobyl accident.

Parts of Greece have been exposed to fallout radiation from the Chernobyl accident as much as any of the countries boardering with the former Soviet Union, because of the direction of the prevailing winds after the accident. Although fallout radiation did not reach levels expected to be associated with measurable effects, there is widespread concern in Greece that the incidence of childhood leukemia may be rising in the more heavily affected parts of Greece. Patient discharge data from all Greek hospitals treating childhood leukemia were used to calculate the annual incidence of the disease from January 1980 to June 1986 (preaccident period), from July 1986 to June 1988 (immediate postaccident period) and from July 1988 to June 1991 ("relevant" post-accident period, that accommodates the presumed latent period of the disease). Fallout radiation measurements (in Bq/kg Cs-137) were used to create 17 regions of similar (within regions) but highly variable (between regions) levels of fallout deposition. Background radiation (in Bq/kg Ra-226) and annual incidence of childhood leukemia by region were also estimated. There was no evidence of increased incidence of childhood leukemia during the immediate or the "relevant" post-Chernobyl period in any part of the country. Furthermore, regression analyses did not show any significant or suggestive association of childhood leukemia by region with either background or fallout radiation. These results indicate that the Chernobyl accident did not affect noticeably the incidence of childhood leukemia in Greece during the five-year post accident period.

Accidents↗
PubMed1993

Cord blood erythropoietin in the presence and absence of labor in normal infants.

To evaluate erythropoietin (Ep) levels in normal labor and cesarean section we studied the cord serum of 111 term pregnancies, divided into three groups: (i) those born by normal vaginal delivery (n = 69); (ii) those delivered vaginally from mothers who were smokers (n = 20); and (iii) those delivered by elective cesarean section (n = 22). The three groups did not differ in maternal age, gestational age, birthweight, infant sex and Apgar scores. No correlation was found between Ep and hematocrit in all three groups of normal terms studied. Although not statistically significant the lower mean Ep value observed in cesarean section compared with the values obtained from normal deliveries could suggest that the process of labor may be a cause of these differences.

Adolescent↗
PubMed1993

Correlation of in vitro enhancement of erythropoiesis and clinical response to steroids in Diamond-Blackfan anaemia.

To investigate whether the clinical response to steroids in Diamond-Blackfan anaemia (DBA) can be predicted in vitro, erythroid cultures from six patients was performed. The increment of burst forming unit erythroid (BFU-E) and colony forming unit erythroid (CFU-E) derived colonies had been studied with the in vitro addition of steroids. Our results showed: 1) a relative insensitivity to low and optimum concentration of erythropoietin (Epo) in cultures, and 2) lower CFU-E and BFU-E colony formation in all cases studied. (CFU-Es of normal controls/10(5) cells; were 85.6, BFU-Es 37.8, while the patients' CFU-E were 18.1 and BFU-E 7/10(5) cells with two IU of Epo) with poor or no growth in three cases, 3) increment up to 60-110% with in vitro addition of steroids in three cases, 4) high serum Epo levels in all Diamond-Blackfan anaemia patients, and 5) clinical response to steroids in the three patients who responded in vitro.

Adult↗
PubMed1993

Serum levels of tumor necrosis factor and soluble interleukin 2 receptor as markers of disease activity and prognosis in childhood leukemia and lymphoma.

The serum levels of soluble interleukin 2 receptor (SIL-2R) and tumor necrosis factor (TNF) were assessed in 69 children from 6 months to 14 years old who suffered from acute lymphoblastic leukemia (39), Hodgkin's disease (15), non-Hodgkin's lymphoma (15) and in 54 normal age-matched controls prior to any therapy and at remission. Both SIL-2R and TNF levels were significantly higher at diagnosis compared with normal controls (P < 0.001), but decreased significantly at remission. The SIL-2R and TNF levels were significantly higher in an advanced stage of lymphoma than in an early stage. In the patients with acute lymphoblastic leukemia (ALL) and lymphoma, higher levels of SIL-2R (> 1030 units/ml) and TNF (> 30 pg/ml) were associated with a poorer treatment outcome (P < 0.01). Our findings indicate that elevated TNF serum secretion together with SIL-2R are useful markers in childhood ALL and lymphoma and can be used to assess both disease activity and prognosis in this group of malignancies.

Adolescent↗
PubMed1992

Proliferating cell nuclear antigen (PCNA) expression in childhood lymphomas.

Paraffin sections from 21 cases of Hodgkin's disease (HD) and 28 cases (26 high-grade and 2 low-grade) of non-Hodgkin's lymphomas (NHL) occurring in childhood were examined for the presence of proliferating cell nuclear antigen using an anti-PCNA antibody. All cases of HD and NHL showed PCNA reactivity. In HD 50.9% (mean value) of Hodgkin and Reed-Sternberg (HRS) cells were PCNA positive and judged to be proliferating. PCNA reactivity was also found in a varying number of cells of the background population in HD (mean value = 11.7%). In NHL 61.2% (mean value) of cells were PCNA positive. In the 26 high grade tumours 63.6% (mean value) of cells were PCNA positive while only 32% (mean value) of cells were PCNA positive in the 2 low-grade tumours. Our results show that the proliferation rate of tumour cells in high-grade NHL is higher than those of tumour cells in low-grade NHL and HRS cells in HD. Moreover, we found a considerable variation of proliferation rate among individual cases of HD (range 31%-68%) of NHL (range 31%-78%). This suggests that PCNA assessment can help in the individual approach of the proliferation rate of each tumour, and, in conjunction with other parameters of the cell proliferation, could be useful for the understanding of the biological behavior of childhood lymphomas.

Adolescent↗
PubMed1992

Expression of the Epstein-Barr virus encoded latent membrane protein in tumor cells of Hodgkin's disease occurring in childhood.

Paraffin sections from 21 cases of Hodgkin's disease (HD), 28 cases of non-Hodgkin's lymphomas (NHL) and 34 cases of non-specific reactive lymphadenitides occurring in childhood were examined for the presence of the Epstein-Barr Virus (EBV)-encoded Latent Membrane Protein (LMP) using a double layer immunohistochemical method. LMP was detected in 12/21 (57%) cases of HD but not in NHL or reactive lymph nodes. LMP reactivity was restricted to Reed-Sternberg and Hodgkin's (HRS) cells in 4 of 9 (45%) cases of nodular sclerosis (NS), 6 of 9 (66%) cases of mixed cellularity (MC) and 2 of 2 (100%) cases of lymphocyte depletion (LD) while it was undetectable in the single case of lymphocyte predominance (LD) subtype. These results provide further evidence for an association between EBV and Hodgkin's disease, and they show that LMP expression occurs more frequently in the clinically more aggressive subtypes of HD. Furthermore, in view of the in vitro transforming potential of the LMP protein, the exclusive immunolocalization of LMP in HRS cells, suggests that EBV may be involved in the pathogenesis of a proportion of cases of HD.

Adolescent↗
PubMed1991

Towards a better understanding of cellular events in Mycosis fungoides: an immunohistochemical study.

In the present work, we have attempted to pay special attention to epidermal and dermal cellular events in Mycosis fungoides (MF). In the epidermis, the two dendritic cell populations, CD1+ and OKM5+, HLe-1+, the adhesion molecules OKM5 and DR on the surface of epidermal cells (Ecs), and cytoskeletal proteins were studied. CD1+ dendritic epidermal cells were generally more abundant than OKM5+, HLe-1+ ones with no interrelationship in their presence. OKM5+, HLe-1+ dendritic cells prevailed in the second stage plaques. The staining pattern with anti-spectrin polyclonal antibody gradually presented increased intensity from Pre-MF to tumor stage. The activation-proliferation related immunophenotype was also examined, as well as other useful markers, in an attempt to correlate their presence in different stages of MF. Special emphasis was given to the staining pattern with the epidermal growth factor receptor (EGF-R) monoclonal antibody against three targets: epidermal, endothelial, and lymphoid cells. The presence of Ki-67 proliferation marker in suprabasal epidermal layers and lymphoid cells in the dermal infiltrate was also of interest.

Cell Division↗
PubMed1991

Serum erythropoietin in regularly transfused thalassemic patients.

Serum erythropoietin levels were measured in 67 regularly transfused thalassemic patients with pre-transfusion hematocrit ranging from 25-32% and in 40 normal individuals. In patients, mean erythropoietin levels were slightly increased (mean 91.5 miu/ml) as compared to normal individuals (mean 42 miu/ml). The distribution of erythropoietin (Ep) was wide in thalassemic patients. 40% had normal or decreased and 60% increased Ep levels. A reverse relation between pretransfusion Hct and erythropoietin activity was observed only among patients with normal erythropoietin levels and splenectomized patients with high erythropoietin titers suggesting that a normal feedback between tissue hypoxia and erythropoietin activity occurs in these groups. The effect of regular blood transfusions in reversing tissue hypoxia resulting from anemia in the majority of regularly transfused thalassemic patients seems to be satisfactory, as it is assessed by serum erythropoietin levels.

Adolescent↗
PubMed1989

Committed erythroid progenitors and erythropoietin levels in anemic children with lymphomas and tumors.

In order to investigate the pathogenesis of anemia in childhood malignancy, we studied erythroid cell proliferation responses with bone marrow erythroid cultures and serum erythropoietin (Ep) levels in 32 children with lymphomas and malignant tumors. The erythroid colony formation from 20 normal controls (mean 68.8 colony-forming-unit erythroid [CFU-E] and 32 burst-forming-unit erythroid [BFU-E] derived colonies/10(5) mononuclear cells), was higher than that seen in children with lymphomas (mean 45.9 CFU-E and 20.7 BFU-E/10(5) cells, p less than 0.01) but similar to the values obtained from children with tumors (mean 65.1 CFU-E and 28.1 BFU-E/10(5) mononuclear cells). The degree of anemia in children with lymphomas correlated negatively (r = -0.7, p less than 0.01) with serum Ep levels. In contrast, a weak positive correlation (r = 0.3, p greater than 0.1) was observed between the degree of anemia and Ep values in the group with tumors. We suggest that the decreased number of committed erythroid progenitors in lymphomas may be the main factor for anemia in these patients, while the abnormal response of Ep to the degree of the anemia suggests a defect in erythropoiesis in children with tumors.

Anemia↗
PubMed1985

Plasmapheresis in paroxysmal nocturnal hemoglobinuria aplastic crisis: clinical improvement and in vitro demonstration of plasma inhibitory activity on erythroid stem cells.

Plasmapheresis was used in a 51 year old woman with known PNH and aplastic crisis unresponsive to conventional treatment. A clinical and laboratory improvement was noted and an in vitro inhibition of BFU-E's obtained from patient's peripheral blood mononuclear cells was observed when autologous plasma or serum were added to cultures. The beneficial effect of plasmapheresis is though to be to the elimination of a plasma inhibitory factor responsible for the aplastic crisis in this PNH case that exerts its action to the committed erythroid progenitors as well.

Anemia, Aplastic↗
PubMed1983

Mechanisms of abnormal erythropoiesis in malignancy.

In order the investigate mechanisms of diminished red cell production in malignancy, we assayed erythroid progenitor cell proliferative responses to erythropoietin in plasma clot cultures of bone marrow cells from 34 cancer patients. Erythroid colony growth by marrow cells of 11 healthy donors (means of 58 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) was similar to that in cultures of cells from patients either with (means of 44 CFU-E and 22 BFU-E derived colonies/6 X 10(4) cells) or without (means of 50 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) myelophthisis. Colony formation was normal at all erythropoietin concentrations tested, indicating that both the CFU-E and BFU-E retain normal erythropoietin sensitivity in vitro. CFU-E proliferation correlated negatively (r = -0.56; P less than 0.001) with the level of hemoglobin. In contrast to marrow cell proliferative responses to erythropoietin, serum erythropoietin levels were inappropriately reduced in all 19 patients in whom they were measured, a finding which may be important in the pathogenesis of anemia in patients with cancer.

Carcinoma, Squamous Cell↗
PubMed1983

Platelet-derived growth factor promotes proliferation of erythropoietic progenitor cells in vitro.

To investigate serum requirements for optimal erythropoiesis in vitro, we studied the response of erythroid progenitor cell proliferation in culture to platelet-derived growth factor (PDGF). Human bone marrow cells cultured with platelet-poor plasma-derived serum (PDS) form fewer erythroid colonies than do cells cultured with human whole blood serum or fetal calf serum (P less than 0.05). Treatment of washed platelets with thrombin releases a low molecular weight (less than 100,000) factor that enhances colony growth. This secreted factor appears to be PDGF, based upon the ability of partially purified and electrophoretically pure PDGF to restore colony-forming capacity of PDS-containing cultures to 70-96% of the level found in control cultures with whole blood serum or fetal calf serum. Enhancement of colony growth by PDGF was noted only in marrow cultures supplemented with erythropoietin and PDS. Presence of bioactive erythropoietin in PDGF preparations was excluded by assay in hypertransfused, polycythemic mice, and in fasted rats. Although PDGF stimulates erythroid burst formation in marrow cultures containing optimal concentrations of burst-promoting activity (BPA), it does not influence proliferation of circulating erythroid bursts, regardless of BPA concentration added to culture. We conclude that PDGF is a serum determinant of optimal erythroid progenitor cell proliferation in marrow culture. The activity of PDGF is distinct from that of the apparent erythroid specific growth factors erythropoietin and BPA.

Animals↗
PubMed1982

Correlation of clinical and in vitro erythropoietic responses to androgens in renal failure.

To assess in vitro erythropoietic cultures as a tool to discriminate between patients whose anemia improves with and those whose anemia fails to improve with androgens, bone marrows of 24 anemic patients receiving maintenance hemodialysis in hormone-depleted plasma clots were cultured. While erythroid colony proliferation in the presence and absence of androgens by cells of seven patients with good clinical outcomes who were initially studied was similar to that of normal donors, it was reduced (P less than 0.001) in cultures of cells from seven patients whose clinical responses were ultimately poor. Fewer than 25 colonies/6 X 10(4) cells at optimal erythropoietin concentrations, and less than a 25% enhancement in colony growth by androgens were observed in only those cultures derived from clinical nonresponder marrows. Using these criteria, nine of ten prospectively classified patients (five clinical responders and four nonresponders) were identified correctly.

Adult↗
PubMedDate not supplied

Aspects of childhood cancer during the Byzantine period.

The main trends in the diagnosis and management of childhood cancer during the Byzantine period (330-1453 CE) are investigated. Therapeutic modalities reflected the influences from Ancient Greek and Greco-Roman medicine. Medical treatment included a great variety of regimens, and surgery was not unknown. The attitudes toward cancer suggest that people of that time did not believe in a superstitious origin of the disease. Even though most of these remedies and many procedures are nowadays out of use, the physicians of the Byzantine period preserved the scientific medical thought of antiquity, improved it, and set the basis of current achievements. Medical terms introduced during the Byzantine period are still used. The texts have been studied in their original languages, that is, Ancient and Byzantine Greek, and Latin.

Byzantium↗