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Biomedical subjects

U Ramenghi

Publications and source records attributed to U Ramenghi.

58 records · Page 4Linked to original sources

[The glucose-6-phosphate dehydrogenase/6-phosphogluconate dehydrogenase ratio in the identification of glucose-6-phosphate dehydrogenase heterozygosity].

Deficiency in human G-6PD is a widespread X-linked disorder, which is mainly characterized by susceptibility to hemolytic anaemia after the ingestion of certain drugs or toxic substances (e.g. pyrimidine derivates contained in fava beans). G-6PD deficiency in hemizygous males in easily detectable since enzymatic activity is almost absent. In heterozygous subjects the determination of enzymatic activity on red cell lysate cannot detect a partial G-6PD deficiency. Cytochemical methods as methemoglobin reduction test or tetrazolium reduction test are more sensitive than spectrophotometric quantitative test, but are not suitable for screening purposes. We measured both G-6PD activity and 6-PGD activity in G-6PD heterozygous females and we evaluated the G-6PD/6PGD ratio. We tested this ratio also in thalassemic traits and in G-6PD heterozygotes with thalassemic trait in order to detect the interference of thalassemic pathology with the phenotypic expression of the gene for G-6PD. We found that the mean G-6PD values were statistically reduced in G-6PD heterozygous females; on the contrary the measurement of true G-6PD activity alone is not a good tool for discriminating heterozygous subjects with and without thalassemic trait. Actually 100% and 79% of values observed were in the normal range +/- 2 DS respectively. The mean G-6PD/6-PGD ratio in heterozygotes for G-6PD deficiency with and without thalassemic trait was lower than normal and the individual values of G-6PD/6-PGD ratio were in the normal range +/- 2 DS only in a few subjects (8.3% and 10.7% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Acute non-lymphatic leukemia in children].

40 children (23 males, 17 females) have been diagnosed have ANLL during the period from february 1970 to september 1981. According to FAB classification, 24 cases were M1,-M2, 9 M3, 3 M4, 3 M5 and 1 M6. At diagnosis, 20 patients (50%) had leukocytes less than 10.000/mmc, 6 (15%) had leukocytes greater than 50.000mmc. Hb levels was 7 g% in 16 patients (40%); 10 children had hepatosplenomegaly (25%), 7 splenomegaly (18%) and 5 lymphoadenomegaly (13%). 4 patients had cutaneous or mucous infiltrates. None had meningeal involvement at diagnosis. According to the year of diagnosis, 3 groups can be identified. In the group I (1970-73), 11 patients have been treated with not codified combination chemotherapy as ARA-C, 6-TG, DNR, CTX, Metil-GAG. In the group II (1974-76) and in the group III (1977-81), the patients (respectively 12 and 17) have been treated according to the following protocols: LAM-5 (3), TRAP (5), COAP (1), LAM 80 (2), AIL 7402 (8), AIL 7604, AIL 7801 (6). Immunotherapy has been performed in 7 cases. CNS prophylaxis (MTX i.t. +/-ARA-C +/- RT) was given in 5 patients of group II and in 6 of group III. I patients of group I (45%), 6 of group II (50%) and 13 of group III (76%) achieved CR. Median duration of remission was 5 months in the group I and in 17 in group II and III.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Diamond-Blackfan anemia: a congenital defect in erythropoiesis.

Diamond-Blackfan anemia (DBA) is a congenital pure red blood cell aplasia diagnosed in the first year of life. Familiarity is apparent in 10% of patients, with all other cases being sporadic. Physical abnormalities are present in at least one third of patients, pointing to a defect in early embryo development. The main clinical sign is profound isolated anemia, with normal numbers and functioning of the other hemopoietic cells. Reticulocyte counts are very low. Bone marrow reflects defective erythropoiesis, showing a very low number of erythropoietic precursors and a reduction of BFU-E progenitor cells. Proliferation and differentiation of the other lineages are normal. The very high erythropoietin (EPO) levels are usually not proportionate to the level of anemia and reflect relative EPO insensitivity, which is also apparent in vitro. Conversely, erythroid progenitors from DBA patients also show a defective or incomplete response to other erythropoietic growth factors, such as IL-3 or IL-6. A significant response has been observed in vitro to stem cell factor in many, but not all patients. Many patients respond clinically to corticosteroids and some develop hematologic remissions, both after corticosteroids and spontaneously. Patients who do not respond to corticosteroids and those who have to discontinue treatment because of side effects must rely on chronic transfusion and are thus exposed to all its complications. Bone marrow transplantation has been performed in some individuals, usually with a successful outcome. This suggests a normal marrow microenvironment and rules out the hypothesis of defective stromal cell function. The variable clinical and biological patterns may be the expression of multiple etiologies or represent variable expressivity of a single genetic defect. Only identification of the responsible gene(s) will solve this question. Growth factors exerting an effect on erythropoiesis (and relative receptors) or transacting proteins which regulate their expression are likely candidates in the hunt for a causal gene.

Animals↗