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Biomedical subjects

X W Wu

Publications and source records attributed to X W Wu.

30 records · Page 2Linked to original sources

[Study on treatment of retinitis pigmentosa with traditional Chinese medicine by Flicker electroretinogram].

Study on treatment of 54 patients (106 eyes) of retinitis pigmentosa (RP) with traditional Chinese medicine was conducted by using modified method of electroretinography. Results showed: (1) Flicker response of electroretinogram was the most sensitive-criterion in examination, it was more effective when combined with infrared spectrogram. (2) The 30 Hz flicker index, response time were improved after TCM therapy in different hereditary types of RP, the improvement was significant in patients with Yang-Deficiency of Spleen-Kidney Syndrome and those of autosomal dominant inheritance type (P < 0.01). (3) Decrease of phase angle (phi) under different frequency of flicker after treatment was also significant statistically. The results suggested that flicker responses, which represents mainly retinal cone activity of patients, could be improved to a certain extent by TCM treatment, even in those with advanced retinal degeneration. TCM treatment could also enhance the bioactivity of nerve network and therefore have a definite significance in retarding the progression of disease and keeping the central vision. The flicker ERG, especially its flicker index, is an effective, sensitive and useful parameter for detection of visual function in patient with retinitis pigmentosa.

Adolescent↗

[Transcervical salpingography and tubal recanalization].

The results of transcervical salpingography and tubal recanalization by means of modified Thurmond and Rösch's technique were reported. Proximal tubal obstruction was diagnosed in 20 infertile women by X-ray hysterosalpingography and/or laparoscopy. Our results showed that tubal recanalization was achieved in 19(95%) of 20 patients, four patients became pregnanCy following the procedure. Distal tubal diseases were seen in 8 of 20 patients. Follow up studies revealed tubal patency was maintained in 7(54%) of 13 patients. The mean radiation dosage received by the patient was 6.35mGy. Compared with Thurmond and Rösch technique the modified technique has the advantage of decreasing the time of fluoroscopy and is a safe, effective and simple method for the diagnosis and treatment of infertile women with proximal tubal obstruction.

Adult↗

Mechanism of platelet aggregation induced by a monoclonal antibody requiring Fc portion.

A monoclonal antibody designated Apt4, which is IgG1, was produced by fusion of mouse myeloma cells to spleen cells from a BALB/c mouse immunized with normal human platelets. Apt4 whole IgG caused the aggregation of both platelet rich plasma (PRP) and washed platelets from normal subjects and a patient with Bernard Soulier syndrome but not those from two patients with the Type 1 Glanzmann's thrombasthenia. No aggregation was observed when Apt4 F(ab')2 fragments were used. Immunofluorescence study showed that both whole IgG and F(ab')2 fragments of Apt4 bound to fresh or formalin fixed platelets from normal subjects and a patient with Bernard Soulier syndrome but not to those from two patients with Glanzmann's thrombasthenia. Aggregation induced by Apt4 IgG was inhibited by EDTA (10 mM), PGE1 (1 mM), 2-deoxy-D-glucose/antimycin (1.4 uM), and apyrase (20 units/ml). Preincubation of normal PRP with monoclonal anti-GPIIb/IIIa or anti-GPIb antibodies completely or partially inhibited the Apt4-induced aggregation, whereas anti-GPIIIa antibodies have no effects on this activation. Monoclonal ant-Fc gamma RII antibody (IV.3) inhibited Apt4 induced aggregation. Immunoprecipitation of 125I-labeled platelet membrane lysate by Apt4 IgG showed two protein bands with a molecular weight of 145,000 and 95,000 daltons respectively under non-reducing condition, which are corresponding to GPIIb and GPIIIa. In conclusion, Apt4 antibody binds to GPIIb/IIIa complex and induces aggregation, requiring energy metabolism, calcium, ADP release and Fc portion of IgG to interact with Fc receptor, but independent of thromboxane A2 formation.

Animals↗

Two independent mutational events in the loss of urate oxidase during hominoid evolution.

Urate oxidase was lost in hominoids during primate evolution. The mechanism and biological reason for this loss remain unknown. In an attempt to address these questions, we analyzed the sequence of urate oxidase genes from four species of hominoids: human (Homo sapiens), chimpanzee (Pan troglodytes), orangutan (Pongo pygmaeus), and gibbon (Hylobates). Two nonsense mutations at codon positions 33 and 187 and an aberrant splice site were found in the human gene. These three deleterious mutations were also identified in the chimpanzee. The nonsense mutation at codon 33 was observed in the orangutan urate oxidase gene. None of the three mutations was present in the gibbon; in contrast, a 13-bp deletion was identified that disrupted the gibbon urate oxidase reading frame. These results suggest that the loss of urate oxidase during the evolution of hominoids could be caused by two independent events after the divergence of the gibbon lineage; the nonsense mutation at codon position 33 resulted in the loss of urate oxidase activity in the human, chimpanzee, and orangutan, whereas the 13-bp deletion was responsible for the urate oxidase deficiency in the gibbon. Because the disruption of a functional gene by independent events in two different evolutionary lineages is unlikely to occur on a chance basis, our data favor the hypothesis that the loss of urate oxidase may have evolutionary advantages.

Amino Acid Sequence↗

Genetic polymorphism of MHC class III and GLO in Chinese Yao nationality.

Yao nationality is one of the minority nationalities living mainly in South China (Guangxi Province). The purpose of this study was to provide data of MHC class III and GLO in Chinese Yao nationality and the different genetic background of Yao and Han nationality, the latter representing the major nationality in China. The genetic polymorphism of MHC class III and GLO in Chinese Yao nationality was determined. Previously the Japanese were considered to have the lowest C2*C frequencies (0.9386), but now we ascertained that the Yao have the lowest C2*C frequencies (0.9336). The data concerning gene frequencies of Yao are presented. They were also compared with the available data of Han.

China↗

Genetic polymorphisms of HLA class III and GLO1 in Chinese Yao nationality.

Yao is one of the minority nationalities located mainly in the South of China (Guang Xi province). The purpose of this study was to examine HLA class III and GLO1 in Yao nationality to identify the difference between Yao and Han. Han is the major nationality in China. Yao has the lowest C2*C frequency (0.9336) in the world. Before this study the lowest C2*C frequency known was that of the Japanese (0.9386). Gene frequencies in Yao are the following: C2*C = 0.9336, C2*B = 0.0664; BF*S = 0.9071, BF*F = 0.0929; C4A*4 = 0.0253, C4A*3 = 0.6061, C4A*2 = 0.2121, C4A*1 = 0.0152, C4A*Q0 = 0.1414; C4B*3 = 0.0051, C4B*2 = 0.0657, C4B*1 = 0.7071, C4B*92 = 0.0455, C4B*95 = 0.0253, C4B*96 = 0.0253, C4B*12 = 0.0051, C4B*Q0 = 0.1212; GLO1*1 = 0.1161, GLO1*2 = 0.8839. We have compared these data with those reported for Han.

Blood Donors↗

Urate oxidase: primary structure and evolutionary implications.

Urate oxidase, or uricase (EC 1.7.3.3), is a peroxisomal enzyme that catalyzes the oxidation of uric acid to allantoin in most mammals. In humans and certain other primates, however, the enzyme has been lost by some unknown mechanism. To identify the molecular basis for this loss, urate oxidase cDNA clones were isolated from pig, mouse, and baboon, and their DNA sequences were determined. The mouse urate oxidase open reading frame encodes a 303-amino acid polypeptide, while the pig and baboon urate oxidase cDNAs encode a 304-amino acid polypeptide due to a single codon deletion/insertion event. The authenticity of this single additional codon was confirmed by sequencing the mouse and pig genomic copies of the gene. The urate oxidase sequence contains a domain similar to the type 2 copper binding motif found in other copper binding proteins, suggesting that the copper ion in urate oxidase is coordinated as a type 2 structure. Based upon a comparison of the NH2-terminal peptide and deduced sequences, we propose that the maturation of pig urate oxidase involves the posttranslational cleavage of a six-amino acid peptide. Two nonsense mutations were found in the human urate oxidase gene, which confirms, at the molecular level, that the urate oxidase gene in humans is nonfunctional. The sequence comparisons favor the hypothesis that the loss of urate oxidase in humans is due to a sudden mutational event rather than a progressive mutational process.

Amino Acid Sequence↗

[Production and application of anti-human platelet GP IIb/IIIa monoclonal antibodies].

Four types of anti-human platelet glycoprotein IIb/IIIa (GP IIb/IIIa)monoclonal antibodies (McAb), termed HIP2, HIP4, HIP7, HIP8, were obtained in our laboratory. All of them recognized GP IIb/IIIa complex except that HIP2 recognized GP IIb. As to the effect of the four McAbs on platelet aggregation, the results showed: 1) HIP4 and HIP8 can completely inhibit platelet aggregation induced by ADP or collagen, but not that induced by thrombin or ristocetin. 2) HIP2 was able to activate platelet aggregation directly. But it is Ca++ and complement dependent; 3) HIP7 did not show any effect on platelet aggregation induced by collagen, ADP, thrombin or ristocetin. When clinically studied, some cases of platelet-associated diseases such as thrombocytasthenia and thrombocytopenia had abnormal responses to the above McAbs. In addition, we also found that these McAbs can stimulate hematopoiesis in CFU-E assay.

Animals↗

Generation of cDNA probes directed by amino acid sequence: cloning of urate oxidase.

Urate oxidase (E.C. 1.7.3.3) catalyzes the oxidation of uric acid to allantoin in most mammals except humans and certain primates. The amino-terminal amino acid sequence for porcine urate oxidase was determined and used in a novel procedure for generating complementary DNA (cDNA) probes to this amino acid sequence. The procedure is based on the polymerase chain reaction and utilizes mixed oligonucleotide primers complementary to the reverse translation products of an amino acid sequence. This rapid and simple cDNA cloning procedure is generally applicable and requires only a partial amino acid sequence. A cDNA probe developed by this procedure was used to isolate a full-length porcine urate oxidase cDNA and to demonstrate the presence of homologous genomic sequences in humans.

Amino Acid Sequence↗