PubMed Health⌕ Search

Biomedical subjects

Z C Wang

Publications and source records attributed to Z C Wang.

At least 37 records · Page 2Linked to original sources
PubMed1993

Combined endovascular embolization of large intracranial arteriovenous malformations and their subsequent surgical resection.

Twelve patients with large arteriovenous malformations (AVMs) were subjected to endovascular embolization followed by surgery. Of the 12 patients, 9 were males and 3 females. Their age ranged from 11 to 37 years. Eleven AVM nidi were more than 6 cm in diameter and one AVM, located in a crucial brain area, was 4 cm in diameter. More than 70% of the AVM masses were excised in 11 of the patients, while under 50% was excised in the remaining patient. Complete excisions of the lesions were achieved in all 12 patients 7-10 days after endovascular embolization. No new major neurological deficits occurred. The results showed that the cerebral AVMs can be effectively operated on after endovascular embolization.

Adolescent↗
PubMed1992

Ultrastructural study of cerebral arteries in Moyamoya disease.

The cerebral arteries in seven cases of Moyamoya disease, demonstrated by angiography were observed by light, transmission and scanning electron microscopy. In two cases, the lumen of the terminal portion of the internal carotid artery was completely occluded by proliferated connective tissue. The characteristic pathologic change was extensive destruction of the smooth muscle cells and the elastica interna. Degeneration and necrosis of smooth muscle cells were obvious in the media. Many condensed organelles and other elements of cellular destruction were dispersed throughout the interstitium. The media was thinned. The proliferated smooth muscle cells in the intima showed the same destructive changes as in the media. The elastica interna was excessively infolded and was thickened or thinned, disrupted or disintegrated in some segments. Identical, but less severe and more localized changes were seen in three middle cerebral arteries (M2 and M5 segments) and two collateral arteries at the base of brain. These changes suggest that Moyamoya disease is a progressive disorder characterized by repeated destruction of smooth muscle cells occurRing over a long time period. The pathogenesis of these changes is discussed.

Cerebral Arteries↗
PubMed1990

Treatment of traumatic carotid-cavernous fistula with detachable balloon.

From November 1986 to February 1989, 18 patients with traumatic carotid-cavernous fistulas were treated by means of detachable balloon, which was made by ourselves. Successful embolization was achieved in 15 patients. Draining features of the fistulas and methods of embolization were introduced. The method was compared with other methods. Selection of treatments and problems in embolization are discussed.

Adult↗
PubMed1990

[Analysis of the therapeutic efficacy and prognostic factors of intensive chemotherapy in 91 patients with acute nonlymphoblastic leukemia].

91 patients with acute nonlymphoblastic leukemia (ANLL) were treated with Homoharringtonine, Cytosine arabinnoside, Thioguanine (HAT) and/or Daunorubicin, (Adriamycin) Cytosine arabinnoside, Thioguanine D(A) AT protocols. The total CR rate was 68.1% with a median remission duration of 20.3 months, and the expectant survival rate in 5 years (Kaplan-Meier method) was 39%. The CR rate and the CR duration projected by HAT and D (A) AT protocols were very similar. After 20 prognostic factors from both clinical and laboratory examinations prior to treatment had been analysed, we concluded that (1) The CR rate was improved by increasing the dose of induction chemotherapy; (2) The patients might have longer remission and survival if they obtained remission in 2 courses of treatment; (3) The remission durations were comparable between the individuals receiving and not receiving maintenance chemotherapy.

Adolescent↗
PubMed1989

Occipital transtentorial approach for removal of pineal region tumors: report of 64 consecutive cases.

A series of 64 patients with pineal region tumors operated on between 1981 and 1985 at the Beijing Neurosurgical Institute is reported. All were approached using an occipital transtentorial technique. A gross total or radical subtotal removal was achieved in 87% with a total mortality and morbidity of less than 10%. The relative advantages of this particular approach to the pineal region are discussed. It is concluded that the transtentorial approach to the pineal region provides excellent visualization and circumvents many of the pitfalls of other approaches to this region.

Adolescent↗
PubMed1989

Effects of adenosine A2 receptor agonists on nucleoside transport.

A series of adenosine A2 receptor agonists were examined for their ability to activate adenosine A2 receptors and inhibit nucleoside transport. A2 receptor activation was measured by the ability of these adenosine agonists to relax porcine coronary smooth muscle, where the compounds varied in their EC50 values from 4.5 nM (CGS 21680A (2-[p-(2-carboxyethyl) phenylethylamino]-5'-N-ethylcarboxamidoadenosine)] to 3.6 microM (CGS 23321 [2 alpha,3 alpha-dihydroxy-1 beta-hydroxymethyl-4 beta-(2-phenylamino-9- adenyl)-cyclopentane]). Nucleoside transport was measured as the nitrobenzylthioinosine-sensitive cellular accumulation of [3H]uridine into guinea pig erythrocytes at 22 degrees C. The initial velocity of transport was dependent on substrate concentration and a substrate-velocity curve yielded a Km of 78 +/- 16 microM and a Vmax of 0.31 +/- 0.049 mmol/l of cell water per hr (mean +/- S.D., n = 4). Dipyridamole, a known potent inhibitor of nucleoside transport, blocked cellular [3H]uridine accumulation with an EC50 of 29.4 nM. Whereas a number of the adenosine agonists tested showed little or no inhibition of nucleoside transport, CV 1808 (2-phenylaminoadenosine) inhibited transport with an EC50 of 140 nM. In addition, two carbocyclic derivatives of CV 1808, CGS 23321 and CGS 23302 [(-)2S,3R-dihydroxy-4R-hydroxymethyl-1R-[2-(p-ethoxycarbonyl)- phenylamino-9-adenyl]-cyclopentane) inhibited nucleoside transport with respective EC50 values of 366 and 168 nM. The data suggest that these compounds have a different structure-activity relationship for adenosine A2 receptors and for the site mediating nucleoside transport inhibition.

Adenosine↗
PubMed1987

[Indirubin in the treatment of chronic myelocytic leukemia (CML)--estimation of labelling index of bone marrow cells by 3H-TdR].

Using 3H-TdR labelling radioautography in vitro, labelling index (LI) of the bone marrow cells from patients with CML was estimated before and after treatment by indirubin, and compared with myleran. The results showed that LI of the bone marrow cells was prone to decline after treatment by indirubin or myleran, and it was most marked on the myelocyte and polychromatophilic erythroblast. The LI reduction was less by indirubin than myleran. It suggests that the inhibition of indirubin on the bone marrow cells be weaker than that of myleran. However, long-term administration of indirubin would inhibit not only the granulocytic series but also the red cell series to a certain degree.

Adolescent↗
PubMed1985

Complex formation and O2 sensitivity of Azotobacter vinelandii nitrogenase and its component proteins.

The O2 stability of the MoFe protein, the Fe protein, a 1:1 mixture of these proteins, and a 1:1 mixture in the presence of the Azotobacter vinelandii FeS-II protein has been studied as a function of time under controlled O2 partial pressures. The Fe protein is much more sensitive to O2 exposure than is the MoFe protein. The presence of the FeS-II protein at a 1:1 ratio with the component proteins measurably increases the O2 stability of the MoFe and Fe proteins. O2 inactivation of the MoFe protein was studied in some detail and found to be quite complex. At least three partially overlapping reactions are suggested. The first is the reversible oxidation of the metal clusters of the MoFe protein to the combined extent of 12 electrons with full retention of activity. The second phase consists primarily of activity loss with little increase in the extent of reversible oxidation. The third phase continues to decrease the protein activity but is also accompanied by formation of a g = 2.0 EPR signal and more extensive oxidation. Ultracentrifugation studies of the FeS-II protein at a 1:1:1 ratio with the Fe and MoFe proteins do not support the formation of the Bulen complex. The formation of other O2-stable complexes is discussed.

Azotobacter↗
PubMed1984

H2-uptake activity of the MoFe protein component of Azotobacter vinelandii nitrogenase.

The MoFe protein from Azotobacter vinelandii catalyzes the reduction of methylene blue and other oxidants by H2 under anaerobic conditions. H2 uptake followed manometrically or by 3H2 transfer from the gas to aqueous phase occurs concomitantly with methylene blue disappearance monitored optically or coulometrically. The stoichiometry was found to be 1:1 methylene blue/H2. MoFe protein oxidized by transfer of approximately 4 e- seems to be the redox state of the protein most active in the catalytic step, although both the S2O4(2-)-reduced and 6-e- oxidized state have been shown to react, but at a much lower rate. The presence of H2 in the atmosphere above the MoFe protein offers increased protection against O2 inactivation.

Azotobacter↗