1/7. hemolysis as a potential complication of acetaminophen overdose in a patient with glucose-6-phosphate dehydrogenase deficiency.A 21-year-old Chinese man who took an overdose of acetaminophen was hospitalized. His medical history was significant for glucose-6-phosphate dehydrogenase (G6PD) deficiency. On admission, physical examination was unremarkable and laboratory results were within normal limits. During his hospitalization, the patient experienced a decrease in hemoglobin concentration of almost 4 g/dl and an increase in unconjugated bilirubin consistent with the development of hemolysis. acetaminophen was the most likely cause of the hemolysis. Clinicians must be aware of this potential complication after acetaminophen overdose in G6PD-deficient patients.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
2/7. Erythrocytosis due to bisphosphoglycerate mutase deficiency with concurrent glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.A 28-year-old asymptomatic male of Iranian Jewish (Meshadi) heritage was found on routine exam to have an erythrocytosis (RBC = 6.22 x 10(12)/l, Hgb = 19.2 g/dl, Hct = 58.9%). splenomegaly was absent on physical exam. There was no family history of erythrocytosis. His oxygen dissociation curve was left-shifted with a p50 of 19 mmHg (normal = 25-32 mmHg). Hemoglobin electrophoresis showed no abnormalities. dna sequencing of the hemoglobin beta globin gene and both alpha globin genes did not reveal a mutation. A 2,3-bisphosphoglycerate (BPG) level was markedly decreased at 0.3 micromol/g Hb (normal = 11.4-19.4 micromol/g Hb). The patient's bisphosphoglycerate mutase (BPGM) enzyme activity was also markedly decreased at 0.16 IU/g Hb (normal = 4.13-5.43 IU/g Hb). A red cell enzyme panel revealed a markedly decreased G-6-PD level (0.3 U/g Hb, normal = 8.6-18.6 U/g Hb). His parents and a brother were also available for evaluation. Both parents showed normal 2,3-BPG levels but BPGM activity approximately 50% of normal. Paradoxically, the brother showed normal BPGM activity but a slightly decreased 2,3-BPG level. All family members had markedly decreased G-6-PD activity. dna sequencing of the BPGM gene showed the propositus to be homozygous for 185 G-->A, Arg 62 Gln in exon 2. Thus, the erythrocytosis in this patient is secondary to low 2,3-BPG levels, due to a deficiency in BPG mutase. This appears due to consanguinity within this family.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
3/7. G6PD deficiency with hemolytic anemia due to a rare gene deletion--a report of the first case in malaysia.A 2-year-old Chinese boy was referred to Hospital UKM for investigation of recurrent episodes of dark-coloured urine and pallor since birth. He was born prematurely at 34 weeks gestation and developed severe early-onset neonatal jaundice requiring exchange blood transfusion. Screening at birth showed glucose-6-phosphate dehydrogenase (G6PD) deficiency. On admission, physical examination revealed pallor, jaundice and mild hepatomegaly. Results of laboratory investigations showed a hemoglobin level of 11.0 g/dl with a hemolytic blood picture, reticulocytosis of 20% and red cell G6PD activity reported as undetectable. The patient's dna was analysed for G6PD mutations by PCR-based techniques and dna sequencing and results showed a 24 bp deletion of nucleotide 953-976 in the exon 9 of the G6PD gene. dna analysis was also performed on blood samples of the patient's mother and female sibling confirming their heterozygous status, although both showed normal red cell G6PD activity levels. The patient was discharged well and his parents were appropriately advised on the condition and the importance of taking folic acid regularly. This is a first case report in malaysia of G6PD deficiency causing chronic-hemolytic anemia. The rare 24 bp deletion causes the G6PD Nara variant, previously reported only in two other unrelated males, a Japanese and a Portuguese both with chronic hemolytic anemia.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
4/7. glucose-6-phosphate dehydrogenase Lodi844C: a study on its expression in blood cells and muscle.glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in erythrocytes, lymphocytes and muscle of an Italian male, whose family has lived for at least three generations in Lodi (Lombardy, northern italy). The subject was hospitalized for myalgia and dark urine after intense physical exercise, but no sign of anemia and chronic hemolysis were present at rest. family studies revealed that the mother and the maternal aunt had the same enzymopathy. The enzyme-specific activity in red blood cells was 15% of control and the kinetic properties were the following: slower electrophoretic mobility; biphasic pH activity curve; slightly reduced thermal stability, and increased utilization of the substrate analogs. The analysis of our patient's dna showed a G C mutation at nucleotide 844 which causes an Asp His amino acid change in position 282. This is the same mutation found by De Vita et al. in the G6PD Seattle-like variant. However, by following a new convention, we labelled our variant as G6PD Lodi844C. As far as the muscle is concerned, we found that the enzyme-specific activity in this tissue was 14% of control values, but cultured myotubes and myoblasts revealed a normal level of G6PD as well as skin fibroblasts. On the contrary in the same type of cultured cells obtained from G6PD Mediterranean subjects, the G6PD activity was about 20% of normal. Our results complete the characterization of this mutant enzyme, demonstrate the expression of the deficit in muscle and describe the enzyme behaviour in cultured cells.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
5/7. Muscle glucose-6-phosphate dehydrogenase deficiency.Muscle glucose-6-phosphate dehydrogenase (G6PD) deficiency is described in four clinically heterogeneous patients: an athlete who developed myoglobinuria after physical exercise; a 7-year-old, mildly mentally retarded boy, who had episodes of dark urine and high creatine kinase; and two brothers of Sardinian origin, the elder showing moderate exercise intolerance. Histochemical and biochemical studies showed a lack of G6PD activity in muscle biopsy specimens as well as in erythrocytes. G6PD characterization in erythrocytes classified these mutant enzymes as Mediterranean variant in all the patients. The deficiency was confirmed in the patients' myotubes and skin fibroblasts, where residual activity was present. Electrophoretic studies in tissue culture extracts showed that the residual muscle enzyme migrated as a single electrophoretic band like normal human muscle G6PD.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
6/7. Fatal familial haemolytic anaemia.A 19-year-old man, mentally handicapped but physically well, died within 2 days of onset of an acute episode of gastrointestinal upset and "haematuria." autopsy and microscopy suggested a haemolytic episode and family studies showed haemolytic anemia due to glucose-6-phosphate dehydrogenase deficiency, which was almost certainly present in the deceased.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |
7/7. Chronic myelogenous leukemia: in vitro studies of hematopoietic regulation in a patient undergoing intensive chemotherapy.A patient heterozygous for the X-linked enzyme glucose-6-phosphate dehydrogenase and with philadelphia chromosome-positive chronic myelogenous leukemia (CML) was treated with combination chemotherapy and had a partial loss of philadelphia chromosome accompanied by partial restoration of nonclonal hematopoiesis as determined by glucose-6-phosphate dehydrogenase. Studies of in vitro hematopoiesis were performed after chemotherapy to evaluate the influences of neoplastic stem cells on normal cells and to determine whether there were physical and cell kinetic differences between leukemic stem cells and their normal counterparts. The data revealed the following: (a) The frequencies of normal committed granulocytic stem cells (CFU-C) and erythroid stem cells (BFU-E) in blood did not differ from the frequencies in marrow. (b) Normal late erythroid progenitors (CFU-E) were found at a significantly lower frequency that the more primitive BFU-E. Calculations indicated that not only was there a decrease in CFU-E production by normal BFU-E, but there was also abnormal clonal expansion of CML BFU-E (CFU-E:BFU-E ratio for normal progenitors was 1.1, whereas for the CML clone it was 11.5). (c) No increase in frequency of normal CFU-C was found after marrow cells were exposed to high specific activity tritiated thymidine. (d) Normal CFU-C and those from the CML clone were not separable on the basis of density. (e) The frequency of normal BFU-E was consistently greater than that of CFU-C, suggesting that regulatory differences influence the commitment of normal progenitors to the two pathways.- - - - - - - - - - ranking = 1keywords = physical (Clic here for more details about this article) |