Glucose-6-phosphate dehydrogenase deficiency.
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Amino Acid Sequence↗
Biomedical subjects
T C Liu
Publications and source records attributed to T C Liu.
Application of ABO genotyping using polymerase chain reaction method to assess engraftment in bone marrow transplantation--a case report.
We described a case of acute promyelocytic leukemia with O blood type who received bone marrow transplantation during a second remission from his HLA identical, B blood type sibling. Using PCR genotyping of the ABO group and analysis of the variable number of tandem repeats of the D1S80 locus, we could quickly document the successful early engraftment in this patient. We emphasize that the use of PCR ABO genotyping is a quick and valuable method which could be applied to assess the engraftment and its follow up in those transplant cases with donors of mismatched blood groups.
ABO Blood-Group System↗
Clonal analysis in acute myeloid leukemia by polymerase chain reaction.
We have used PCR to amplify a polymorphic portion of the X-chromosome linked phosphoglycerate kinase gene (PGK) combined with a methylation-sensitive restriction enzyme digestion of the active X chromosome to examine the frequency of heterozygosity in Taiwanese females and analyze clonality in 18 female patients with acute myeloid leukemia (AML). We used hair follicles as normal tissue control. We found that the incidence of heterozygosity of the PGK gene in 102 hematological normal females and 18 patients tested was 35% (42/120). In five AML patients, a monoclonal X-inactivation pattern of leukemic blasts was found at presentation, which then returned to polyclonal at remission. In two of these five cases, a monoclonal pattern recurred at relapse. We also found that the hair follicles were readily accessible normal tissue for control, were easy to obtain, and were non-invasive.
Base Sequence↗
MDR1 gene expression in acute myeloid leukemia: clinical correlation.
Acute myeloid leukemia (AML) has a poor long-term prognosis, with a disease-free survival rate of only 20%. Drug resistance remains the major obstacle in this disease, although relatively little data are available on the correlation of multi-drug resistance (MDR) and clinical outcome. We examined 28 bone marrow samples from 24 patients with AML. The MDR1 RNA levels were determined by slot blot analysis. The incidence of positive expression of MDR1 mRNA in patients was 64.7% in samples from newly-diagnosed patients and 85.7% in relapse samples. The overall complete remission rate was 45%. However, the complete remission rate was lower for patients in the MDR1 RNA positive group than in the negative group. In three cases, the MDR1 RNA expression steadily rose during the period of disease progression and after several courses of chemotherapy. We suggest that a high frequency of MDR1 gene expression in patients with AML and higher MDR1 RNA levels are associated with a lower incidence of complete remission as well as a shorter disease-free time. The expression of MDR1 is a poor prognostic factor for AML treatment and it may play an important role in resistance to chemotherapy.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Chronic neutrophilic leukemia--a case report.
We describe a 77-year-old patient with chronic neutrophilic leukemia (CNL). Diagnosis of CNL was made by marked increase of mature neutrophils without increased immature granulocytes, splenomegaly and elevated serum vitamin B12 level and by ruling out any infection or occult malignancy. The chromosome analysis showed one abnormal karyotype out of 14 metaphases. The neutrophilic function with nitroblue tetrazolium test revealed impaired phagocytic function in this patient. The neutrophil count became normal gradually after hydroxyurea treatment. However, it still maintained a high percentage of mature neutrophils. Background literature and the prognosis of CNL are discussed.
Aged↗
The role of discriminant functions in screening for beta-thalassaemia traits during pregnancy.
INTRODUCTION: The mean red cell volume (MCV) has been shown to be useful in a 2-stage screening process for beta-thalassaemia traits among pregnant women though associated with a large number of false positive results. We tested prospectively the ability of 5 discriminant functions (DF), (England & Fraser, Shine & Lal, Mentzer, Srivistava and Klee et al) to reduce the number of false positives when used as additional screening determinants for beta-thalassaemia in antenatal patients with red cell microcytosis. METHODS: The diagnostic performance of each DF was compared in 493 patients with microcytosis and known beta-thalassaemia status. Truth table analysis and Receiver Operation Characteristic curves for each function were determined. RESULTS: 11.4% of the patients with microcytosis were diagnosed to have beta-thalassaemia traits. DFs incorporating the red cell indices: haemoglobin or total red cell count are unsuitable during pregnancy. Shine & Lal's index [(0.01 x MCH x (< MCV)2] reduced the number of people recalled for confirmatory testing by 31.1% and increased the diagnostic yield to 38.7% while maintaining a negative predictive value for the test of 0.993. CONCLUSION: We conclude that a 3-stage screening process for beta-thalassaemia among pregnant women in Singapore involving the MCV, Shine & Lal's index and a confirmatory test to be both valid and cost-effective.
Diagnosis, Differential↗
Primary amino acid sequence and structure of human pyruvate carboxylase.
Pyruvate carboxylase (PC) (pyruvate:carbon dioxide ligase (ADP-forming), EC 6.4.1.1.), a nuclear-encoded mitochondrial enzyme, catalyzes the conversion of pyruvate to oxaloacetate. We have isolated and characterized cDNAs spanning the entire coding region of human PC. The sequence of human PC has an open reading frame of 3537 nucleotides which encodes for a polypeptide with a length of 1178 amino acids. The identity of the cDNA as PC is confirmed by comparison to PC cDNAs of other species and sequenced peptide fragments of mammalian PC. The M(r) of the full length precursor protein is 129,576 and that of the mature apoprotein is 127,370. RNA blot analysis from a variety of human tissues demonstrates that the highest level of PC mRNA is found in liver corresponding to this tissue's high level of PC activity. Based on homology with other biotin-containing proteins, the ATP, pyruvate, and biotin-binding sites can be identified. One of two patients with documented PC deficiency was found to be missing PC mRNA, further confirming the identity of this cDNA.
Amino Acid Sequence↗
Molecular basis and hematological characterization of Hb H disease in southeast Asia.
We molecularly characterized sixty-seven cases of Hb H disease by the polymerase chain reaction. The strategy depends on amplifying the alpha-thalassemia-1 (alpha-thal-1) gene by primers flanking the breakpoint and sequence differences of the 3' end of the alpha-globin gene and the nonhomologous elements I, II, and III among different types of alpha-thala-2. In the 67 cases studied, all involved alpha-thal-1 of the Southeast Asia type (SEA) in combination with deletional or nondeletional alpha-thal-2. Thirty-two cases were of the deletion form and 35 cases were of the nondeletion form. In 32 cases of the deletion form, 29 cases were rightward deletion (-alpha 3.7), and three cases were leftward deletion (-alpha 4.2). We found that all of the nondeletion forms were alpha-thal-1 of SEA type with Hb CS. After the subtyping of Hb H with -alpha 3.7, 26 out of 29 were type I deletion and 3 out of 29 were type II deletion. Comparisons of clinical data of deletion forms and the nondeletion form showed that there were earlier occurrence of anemic symptoms and a larger erythrocyte volume in the nondeletion form group (P < 0.005).
Asia, Southeastern↗
Rapid molecular characterization of Hb H disease in Chinese by polymerase chain reaction.
We have developed a rapid method to molecularly distinguish different types of Hb H disease. The study depended on (a) most of the Hb H disease in Taiwan having an alpha-thalassemia-1 of the Southeast Asia type (--SEA) in one allele and (b) the differences of X box of alpha-globin gene cluster in the other allele. To detect the --SEA allele, we utilized the primers located on either side of the breakpoint to do PCR, then characterized the amplified products. For the other allele, we sequenced part of the X box, and found that bases -2803 to -2461 of the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene. In -alpha 4.2, the bases belonged to the X box of alpha 1 globin gene, whereas in alpha CS alpha it contained both X boxes of alpha 1 and alpha 2 globin genes. There was an MboII site at this region of the X box of alpha 2 globin gene. We utilized PCR to amplify this region and digested it with restriction enzyme MboII, then combined it with another PCR of different types of Hb H disease. One hundred and one cases of Hb H disease from different families were studied: all of the cases had one allele of --SEA deletion, while the other allele showed that 52/101 were -alpha 3.7, 41/101 were alpha CS alpha, 7/101 were -alpha 4.2, and 1/101 was -alpha G. Taichung. Of 52 cases of Hb H with -alpha 3.7, 47 were type-I deletion and five were type-II deletion.
Alleles↗
Rapid detection of -alpha 4.2 deletion of alpha-thalassemia-2 by polymerase chain reaction.
We sequenced part of the X boxes of alpha-thalassemia-1 of Southeast Asia type (- -SEA) with -alpha 4.2, -alpha 3.7, -alpha G-Taichung, and alpha CS alpha. We found the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene and the X box of alpha CS alpha contained X boxes of both alpha 1 and alpha 2 globin gene, whereas the X box of -alpha 4.2 and -alpha G-Taichung was a hybrid of X boxes of alpha 2 and alpha 1 globin gene. We also found there are two types of -alpha 4.2 deletion; type 1 is a common type of -alpha 4.2 deletion and type 2 is linkage to -alpha G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of alpha 2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the alpha-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of -alpha 4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.
Base Sequence↗
Diagnosis of thalassaemia by non-isotope detection of alpha/beta and zeta/alpha mRNA ratios.
The alpha/beta and zeta/alpha messenger RNA (mRNA) ratios in the thalassaemia syndromes were investigated by polymerase chain reaction (PCR) with silver staining of the PCR products. In this study we used the PCR to amplify cDNA copies of circulating erythroid cell mRNA in order to measure the relative amounts of alpha-, beta- and zeta-globin contained within. Quantitation was performed by scanning the silver stain of specific globin cDNA bands. We found that there were significant differences of alpha/beta-mRNA and zeta/alpha-mRNA in patients with Hb H disease and alpha-thalassaemia-1 compared to normal subjects. There was a marked increase in the alpha/beta-mRNA ratio but not in the zeta/alpha-mRNA ratio in patients with beta-thalassaemia. In two beta-thalassaemia cases abnormal increases of zeta-globin bands were noted and they were confirmed through DNA analysis to be combined with alpha-thalassaemia-1. This method provides a simple, rapid and non-radioactive approach to detect thalassaemia syndromes, and can help to screen cases of beta-thalassaemia with alpha-thalassaemia-1.
Adult↗
Differential actions of phospholipase C on gonadotropin-releasing-hormone-stimulated release and glycosylation of luteinizing hormone in rat anterior pituitary cells.
Receptor-mediated activation of phospholipase C (PLC) which releases diacylglycerol and inositol trisphosphate has been implicated in the action of gonadotropin-releasing hormone (GnRH) on gonadotrophs. Previously we demonstrated that the synthetic diacylglycerol, phorbol 12-myristate 13-acetate (PMA) and PLC mimic the stimulatory effects of GnRH on both luteinizing hormone (LH) glycosylation and release. In this study we further investigated how PMA or PLC interact with GnRH to control LH release versus glycosylation. Cultured pituitary cells were incubated in the presence of radiolabeled precursors and GnRH (0, 1, or 100 nM), with or without PMA (10 nM) or PLC (0.24 U/ml) for 4 h. LH translation and glycosylation were monitored by measuring incorporation of [14C]alanine and [3H]glucosamine, respectively, into total (cell and medium) immunoprecipitable LH. Immunoreactive LH (IRLH) was measured by radioimmunoassay. Both PMA and PLC increased (p < 0.01) basal IRLH release, and IRLH release stimulated by 1 nM GnRH. Neither PMA nor PLC exerted an additive effect on IRLH release stimulated by 100 nM GnRH. The interactions between PMA or PLC and GnRH on IRLH release were significant (p < 0.01). Both PMA and PLC elevated (p < 0.01) total [3H]glucosamine-LH, but had no additive effect with 1 nM GnRH; PLC depressed (p < 0.05) the stimulatory effect of 100 nM GnRH, whereas PMA had no effect. The interactions between PMA or PLC and GnRH on LH glycosylation were significant (p < 0.01). PMA, PLC or GnRH alone did not affect total [14C]alanine-LH. In the presence of 1 or 100 nM GnRH, PLC, but not PMA, decreased (p < 0.05) total [14C]alanine-LH.(ABSTRACT TRUNCATED AT 250 WORDS)
Alanine↗
[Rhinocerebral mucormycosis in a case of malignant lymphoma].
Mucormycosis, an uncommon opportunistic fungal infection, usually occurs in immunocompromised patients. It is rapidly progressive and almost always fatal. Patients with lymphoma are susceptible to pulmonary or disseminated mucormycosis, whereas rhinocerebral mucormycosis in such patients, as far as we know, is rarely reported. We present a patient with malignant lymphoma who exhibited such an acute rhinocerebral infection after chemotherapy which manifested initially as a stuffy nose and intractable headache. Then ptosis, proptosis, chemosis and multiple cranial nerve palsies appeared. Eschar was found in the nasal cavity. Direct KOH smear and tissue biopsy revealed mucormycotic infection. He survived because of early diagnosis and prompt treatment.
Brain Diseases↗
[Diagnosis and treatment of hydronephrosis: report of 100 cases].
One hundred patients with hydronephrosis were treated for 10 years. In 88 patients operations confirmed the causes of obstruction including pyelo-ureteral junction obstruction (pujo, 46 cases), anomalous (15), retroperitoneal fibrosis (15), ureteral polyps and valves and others (12). In accordance with etiology and renal function pyeloplasty was carried out in 31 cases, nephrectomy 37 and nephrostomy 12; other operation was done in 20 cases. The successful rate of pyeloplasty was 91.3%. Early diagnosis and treatment of hydronephrosis is key for reserving renal function. Renal r-scan, percutaneous nephrostomy are useful in judging renal function. Dual-Flex stent internal drainage is better than external drainage when pyeloplasty is done.
Adolescent↗
Screening for beta thalassaemia and HbE traits with the mean red cell volume in pregnant women.
Both beta thalassaemia and HbE disease are microcytic red cell disorders. Pregnancy however induces macrocytosis which makes screening with the mean cell volume (MCV) difficult in antenatal patients. In addition, population screening for HbE has not been widely reported in the literature and the screening criteria for beta thalassaemia may not necessarily apply. A study of the value of the MCV for routine screening for both beta thalassaemia and HbE traits in 3696 antenatal patients of different gestational ages was carried out. All patients with an MCV < or = 80 fL received confirmatory tests for haemoglobinopathies. The MCV rose by only 2.0% in pregnancy. A total of 494 patients (13.4% of the general population) had an MCV < or = 80 fL. Of these microcytic patients, 11.3% (56) and 4.7% (23) were eventually confirmed to have beta thalassaemia and HbE traits respectively. The mean MCV for the 3696 antenatal patients was 87.8 fL (SD 7.5) compared to patients with beta thalassaemia and HbE traits, which were 67.5 fL (SD 4.5) and 75.7 fL (SD 4.1). HbE traits were less microcytic than beta thalassaemia traits and overlapped significantly with the general population. Beta thalassaemia trait and HbE trait detected by this screening method constituted 1.52% and 0.62% respectively of the total antenatal population screened. The MCV remains a valid screening parameter in pregnancy for beta thalassaemia trait. As for HbE trait, applying a discriminant value of 80 fL to the MCV in the population screening would miss a significant proportion of the HbE traits.(ABSTRACT TRUNCATED AT 250 WORDS)
Erythrocyte Indices↗
Molecular basis of beta-thalassemia minor in Taiwan.
The mutations producing beta-thalassemia minor in 227 Taiwanese were studied using the method of naturally and amplified created restriction sites. beta-Thalassemia minor was caused by one beta-globin gene mutation in most of the cases (225/227); only a few cases were caused by two gene mutation (2/227). The most common type of mutation was frameshift codon 41/42 (-TCTT) (93/227), followed in descending order by the C-->T substitution at nucleotide 654 of IVS-2 (83/227), the nonsense mutation A--T at codon 17 (22/227), the A-->T mutation at position -28 of the promotor region (12/227), the frameshift codon 27/28 (+C) (6/227), the initial codon mutation (ATG-->AGG) (5/227), and one each of the codon 71/72 (+A), IVS-1 nt 1 (G-->T), IVS-1 3' end (TAG-->GAG), and nonsense codon 43. In the two cases of the two-gene mutation, one was the nt 654 mutation with Hb Kaohsiung and another one was frameshift codon 41/42 with Hb Meinung. The first four mutations accounted for more than 90% of the mutations. The C-->T substitution at the nt 654 of IVS-2 and initial codon mutation in our study had a higher incidence than in other Southeast Asia areas. Comparison of clinical data in different types of beta-thalassemia showed that there were higher MCV and MCH levels in beta (+)-thalassemia.
Adolescent↗
Identification of two missense mutations in a dihydrolipoamide dehydrogenase-deficient patient.
The molecular basis of dihydrolipoamide dehydrogenase (E3; dihydrolipoamide:NAD+ oxidoreductase, EC 1.8.1.4) deficiency in an E3-deficient patient was studied. Fibroblasts cultured from the patient contained only approximately 6% of the E3 activity of cells from a normal subject. Western and Northern blot analyses indicated that, compared to control cells, the patient's cells had a reduced amount of protein but normal amounts of E3 mRNA. Direct sequencing of E3 cDNA derived from the patient's RNA as well as each of the subclones of the cDNA revealed that the patient had two substitution mutations in the E3 coding region. One mutation changed a single nucleotide from A to G, resulting in substitution of Glu (GAA) for Lys-37 (AAA). The other point mutation was a nucleotide change from C to T, resulting in the substitution of Leu (CTG) for Pro-453 (CCG). These mutations appear to be significant in that they alter the active site and possibly the binding of FAD.
Amino Acid Sequence↗
Rapid diagnosis of hemoglobin constant spring and hemoglobin E by amplified created restriction sites.
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Base Sequence↗