Biomedical subjects

W Z Xu

Publications and source records attributed to W Z Xu.

13 recordsLinked to original sources

PubMed1992

Diameter of the cochlear nerve in deaf humans: implications for cochlear implantation.

Although the parameters that are most important for postoperative speech perception in cochlear implantation have not been identified, it is assumed that the numbers of remaining cochlear neurons and spiral ganglion cells in the implanted deaf ears are critical. In this study, we evaluated the correlation of the maximum diameter of the cochlear and vestibular nerve trunks with the number of spiral ganglion cells in horizontal sections of the temporal bone of 42 patients who were profoundly deaf during life, and in 5 patients with normal hearing. The maximum diameters of the cochlear, vestibular, and eighth cranial nerves were significantly smaller in the deaf population as compared to normal-hearing controls. In addition, the counts of the remaining spiral ganglion cells were significantly correlated with the maximum diameter of the cochlear (p = .0006), vestibular (p = .001), and eighth cranial nerves (p = .0003). The regression equation estimated that 25% of the variance of the spiral ganglion cell count was predicted by the maximum diameter of the eighth nerve. Although the results of this study suggest that preoperative radiographic imaging of the diameter of the eighth nerve may be helpful in predicting the residual spiral ganglion cell count, the wide variability of diameters of the eighth nerve in hearing and deaf subjects militates against this theoretic usefulness.

Adult↗

PubMed1992

[A laboratory and clinical study of induced differentiation therapy by all trans-retinoic acid in acute promyelocytic leukemia].

According to investigations, it was shown that peripheral blood WBC count increased, percentage of promyelocytes increased, differentiation features emerged, protein kinase C (PK-C) activity elevated, intracellular lysozyme content increased, CFU-F productivity increased and typical t (15; 17) disappeared, when induced differentiation therapy with all trans-retinoic acid (RA) was carried out in patients with acute promyelocytic leukemia. Comparison between RA group and RA+Harringtonin/Ara-C group showed no significant difference in most of the parameters; the curative effect was same in both groups. Complete remission (CR) rate was achieved in 92.6% (25/27 cases) of the patients in the entire group. In order to increase CR rate, prevention and treatment for haemorrhagic complications are critical. Patients with hyperleukocytosis (WBC > or = 100 x 10(9)/L) should be treated with intensive combined therapy as well as aggressive prevention of haemorrhage and pathological changes of lung and brain.

Adolescent↗

PubMed1991

Sequence and properties of beta-xylosidase from Bacillus pumilus IPO. Contradiction of the previous nucleotide sequence.

The nucleotide sequence of the beta-xylosidase (xynB) gene from Bacillus pumilus has been reported previously [Moriyama, H., Fukusaki, E., Crespo, J.C., Shinmyo, A. & Okada, H. (1987) Eur. J. Biochem. 166, 539-545]. However, the sequence identified in the present study is quite different from the previously reported one. The total length of the PstI--EcoRI fragment of a plasmid pOXN295 containing the xynB gene is 2201 bp from our sequencing, while the length of the fragment in the previous data was 2466 bp. The sequences are similar in the N-terminal (500 bp) and C-terminal (260 bp) regions, but those in the central region are completely different. From the following observations, the previous sequence seems to have no reliable experimental basis. First, the restriction sites observed for pOXN295 are quite different from the sites deduced from the sequence. Second, the amino acid composition deduced from the sequence and the composition identified by amino acid analysis of the purified beta-xylosidase are very different. It is confirmed, on the other hand, that our new sequence agrees well with these experimental data. The enzyme was purified to homogeneity from Bacillus pumilus and Escherichia coli harboring a hybrid plasmid which highly expresses the xynB gene. The molecular mass of the enzyme was estimated to be 190 kDa by high performance gel filtration chromatography using TSK-G3000SW and 56 kDa by SDS/polyacrylamide gel electrophoresis. The pH optimum was 7.0, and the optimum temperature was 40 degrees C. The Vm value was estimated to be 1.23 +/- 0.14 mukat/mg (or p-nitrophenyl beta-D-xyloside) and 0.14 +/- 0.011 mukat/mg (for xylobiose), while Km was estimated to be 3.9 +/- 0.59 mM (for p-nitrophenyl beta-D-xyloside) and 8.9 +/- 1.19 mM (for xylobiose).

Amino Acid Sequence↗

PubMed1989

[Preliminary study on red cell immune adherence inhibitory activities in serums of myasthenia gravis patients].

The serum inhibitory activities on RBC-C3b receptor rosette of healthy individuals were studied in myasthenia gravis (MG) patients. The serum inhibitory activities appeared in 65% of MG patients. The serum inhibitory activities of generalized type MG were higher than those of ocular type MG. It was also found that the serum inhibitory activities were correlated with the RBC-C3b receptor rosette rate and immune complex (CIC). Furthermore, it was identified that the CIC of MG serums possessed the inhibitory activity on RBC-C3b receptor rosette.

Antigen-Antibody Complex↗

PubMed1989

[A preliminary study on immune complexes in myasthenia gravis].

The levels of circulating immune complex from 43 patients with myasthenia gravis (MG) and 50 normal controls were detected by using ELISA based on bovine conglutinin. The levels of circulating immune complex in MG patients were higher than those in normal controls (P less than 0.01). Although the levels of circulating immune complex in generalized type MG were higher than those in ocular type MG, the difference showed no statistically significant. It was found that the levels of circulating immune complex, both generalized type MG and ocular type MG, were higher than those in normal controls respectively (P less than 0.01).

Adolescent↗

PubMed1988