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Biomedical subjects

X F Zhang

Publications and source records attributed to X F Zhang.

At least 91 records · Page 5Linked to original sources
PubMed1989

The longitudinal observation of the effect of antibiotics on human tear lysozyme activity.

It is well known that lysozyme, which catalyzes the hydrolysis of bacterial cell walls, is one of the important substances protecting the eye surface from bacterial infections. It was reported that the aminoglycoside antibiotics strongly inhibited the tear lysozyme activity. The lysozyme activity of tears which were added to different concentrations of two aminoglycoside antibiotics and three other antibiotics was determined longitudinally. No influence of any antibiotics on tear lysozyme activity was found. Therefore it is unnecessary to worry about that the use of aminoglycoside antibiotics may weaken the defence function of the eye.

Anti-Bacterial Agents↗
PubMed1989

[Combined surgery of vitrectomy and intraocular foreign body extraction].

In combination with vitrectomy, plus lensectomy, optic iridectomy, or IOL implantation as indicated, 121 cases of intraocular foreign body extraction were performed, in which 75.2% of the f. b. were non-magnetic, the number of f. b. in one eye ranged from 1-7, and 93.1% of the vitrectomy were of the closed type. The extraction of f. b. was successful in 97 (80.2%) of the cases on the first attempt, and the total success rate was 96.7%, including those of secondary operations. The instrumentation and procedures involved were also reported.

Adolescent↗
PubMed1989

[Relationship between bacterial envelope barrier and resistance of E. coli, S. aureus to rifamdine].

The Rifamdine (RFD) resistant strains were obtained from wild types of S. aureus NCTC 6571, E. coli NCTC 10418 and Proteus vulgaris by drug concentration gradient plate. The experiment indicated that the growth inhibition of resistant cells induced by synergism of EDTA acting with RFD. Such results did not occur effectively if EDTA or RFD was added separately. The amount of 3H-RFD incorporated into cells of susceptible and resistant strains of E. coli and S. aureus was compared. The amount of 3H-RFD incorporated into susceptible cells was much greater than that of the resistant strains in E. coli cells. Ultrastructure comparison of sensitive and resistant cells showed that the surface of resistant cells was coarser and shorter, the outer membrane thickened and electron density increased. These results have shown that there is a close relationship between the resistance of bacteria induced by RFD and the decrease in the permeability of cell envelope barrier to the drug.

Antibiotics, Antitubercular↗
PubMed1988

Magnesium mediated change in physical state of phospholipid modulates membrane ATPase activity.

During reconstitution of pig heart mitochondrial H(+)-ATPase in soybean phospholipid liposomes by the cholate dialysis method, Mg2+ greatly enhanced 32Pi-ATP exchange activity, ATPase activity and the sensitivity to oligomycin or DCCD of the reconstituted enzyme complex. The effect of Mg2+ on the lipid packing or fluidity of the reconstituted proteoliposomes was measured by means of spin labels, fluorescent probes and pyrene excimer formation efficiency. A difference in fluidity seemed to be localized near the polar faces of lipid bilayers of the reconstituted enzyme complex. Fluidity was less in the presence of Mg2(+)-containing and the Mg2(+)-'free' samples. Based on the results obtained a hypothetical scheme was proposed for Mg2(+)-mediated change in the physical state of phospholipid modulates incorporating H(+)-ATPase in liposomes. It postulated that Mg2+ may play a role in altering the lipid fluidity of the bilayers, which would induce a change of conformation of F0 portion (buried in the lipid core) of H(+)-ATPase complex. Such change could be transmitted to the soluble F1 portion, the conformation of which is in turn altered, resulting in higher enzymatic activity. Such an assumption was further supported by the results of a series of biochemical and biophysical experiments. Similar to its effect in the reconstitution of porcine heart mitochondrial H(+)-ATPase in liposomes, Mg2+ may also enhance the enzyme activity of reconstituted cytochrome C oxidase, porcine kidney medulla Na,K-ATPase, Ca-ATPase from rabbit sarcoplasmic reticulum and chloroplast H(+)-ATPase, in liposomes. It may be inferred that the structure and function of many membrane proteins are similarly modulated by Mg2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1987

[Long-term results of an operation alone and postoperative adjuvant chemotherapy in advanced gastric cancer--report of 265 patients].

During the period from June 1973 to December 1978, 338 patients with advanced gastric cancer were treated in our hospital. By retrospective grouping, 142 out of 265 patients with tumor resected received postoperative adjuvant chemotherapy (MMC + 5FU + Ara-C), 123 operated alone were taken for comparison. These two groups were similar in: age, sex, location of tumor, mode of resection, histological type, clinical stage and follow-up rate. The results indicated that the 1, 3 and 5 year survival rates of the combined group were much higher than those of the operation only group. Further analysis showed that the supplementary chemotherapy was particularly valid in stages III and IV. In stage III patients, the 5 year survival rate was increased by 27.8%. In stage IV patients, the 3 and 5 year survival rates of the combined group were 16.3% and 9.8% but none survived over 3 years in the operation only group. The authors believe that postoperative adjuvant chemotherapy plays an important role in controlling the micrometastatic and residual cancer foci.

Adenocarcinoma↗
PubMed1985

Comparison of the effects of one-side- and two-side Mg2+ on the reconstitution of mitochondrial H+-ATPase.

Three types of proteoliposome containing mitochondrial H+-ATPase have been prepared: Mg2+-'free', one-side and two-side Mg2+-containing proteoliposomes. The ATPase activity as well as its sensitivity to oligomycin or N,N'-dicyclohexylcarbodiimide of the three proteoliposome preparations has been compared. They decreased in the order: L X (H+-ATPase)+ Mg2+ greater than L X (H+-ATPase)-+ Mg2+ greater than L X (H+-ATPase)-Mg2+. The fluidity of the proteoliposomes has also been compared by fluorescence polarization probes diphenylhexatriene (DPH) or 7-(9-anthroyloxy)stearic acid (7-AS). The degree of polarization for DPH in these proteoliposomes decreased in the order: L X (H+-ATPase) +Mg2+ greater than L X (H+-ATPase)-+ Mg2+ greater than L X (H+-ATPase)-Mg2+, while that for 7-AS: L X (H+-ATPase) +Mg2+ approximately equal to L X (H+-ATPase)-+ Mg2+ greater than L X (H+-ATPase) -Mg2+.

Animals↗
PubMed1985

Intercostal-lumbar-spinal nerve anastomoses for cord transection. A preliminary investigation.

Since 1978, 10 intercostal nerve-cauda equina anastomoses and 11 intercostal nerve-lumbar anastomoses were performed for thoracolumbar spinal cord transection. Three to four pairs of intercostal nerves above the traumatic level of the cord were anastomosed with two to four pairs of cauda equina or lumbar nerve roots below the traumatic level, using microsurgical technique. The surgical techniques used for the latter 11 cases were performed through an extraperitoneal approach. The operative technique is described in detail. These 21 cases have been followed-up for six to 48 months. Electromyography (EMG) shows that action potentials are present in several previously paralyzed muscles in 11 cases. Muscle strength of some previously paralyzed muscles in three cases recovered to Grades 1 to 3. There is evidence that intercostal-lumbar-spinal nerve anastomoses provide a chance for neuronal regeneration, but unsatisfactory functional results are still questions for further study.

Adult↗
PubMed1984

Preliminary report on AT1727 as a potential radiosensitizer.

AT1727 is a derivative of ICRF 154. The purpose of this study was to evaluate its "radiosensitizer" properties. From October 1979 until the end of December 1980, 89 patients with radiation resistant cancers such as soft tissue sarcoma, squamous lung cancer (with large lesion, 6-8 cm diameter) and other cancers had been included in trial. Radiation therapy was carried out using CO60 or 8 Mev Linac. Fifty-five patients had a remarkable objective remission rate of 61.8% (55/89). Eighteen of 30 patients with soft tissue sarcomas obtained obvious remission (60%), and 26 of 38 patients with lung cancer had remission (68.4%). Patients with esophageal cancer (5/6) and nasopharyngeal cancer (5/5) also had good remission rates. The side-effects of this treatment were very mild: anorexia and vomiting were noted in 50% and no significant changes were noted in liver and kidney function tests and blood platelet count. Leucopenia was slight in all but one patient. No difference in the lung fibrosis rate was noted between the two randomized groups. From the results of this study we concluded that AT1727 had some effect as a "radiosensitizer" but much more work is needed to confirm this.

Clinical Trials as Topic↗
PubMed1984

Small cell carcinoma of the lung: results of combination chemotherapy and radiation therapy (COF vs. COFP randomized analyzed).

Forty-three patients with small cell carcinoma were admitted to our hospital in 1977. These patients were treated with combined chemotherapy and radiotherapy, the latter being CO60 or 8 MEV Linac. The protocol for treatment is the following: 1) Chemotherapy, randomized into two groups COF (Cytoxan, Vincristin, and 5-fluorouracil) and COFP (Cytoxan, Vincristin, 5-Fu and Procabazine). 2) Radiotherapy with 2 split courses. In the rest period chemotherapy was given as randomized above for COF and COFP groups, but drugs given only once in this rest period, followed by the whole course of radiotherapy using same drugs as above, but only once a month for at least 2 years. The 1-year survival rates were 63.1% and 57.8% respectively, 2-year survival rates were 21% for both programs, and 3-year survival rates were 10.5% for both programs also. Therefore, we believe that procarbazine does not play a very important role in the program, and can be dispensed with. Compared with international reports, the efficacy of COF and COFP programs is as good as any other of the combined chemotherapy programs in the world. These programs may be of more benefit to the patients because of the very mild toxicity and very low cost. In this study the extent of the lesion was found to play important role in prognosis, in other words, the earlier the stage the better the results, just as for other solid tumors. Median survival time in Stage II groups is 20 months, the 1-year survival rate is 81.8% (8/11), 2-year survival rate is 45.4% (5/11), while in Stage III groups median survival time is 11.5 months, the 1-year survival rate is 57.1% (13/21), and 2-year survival rate is 14.2% (2/21). Because the survival time exceeded 18 months, there are 10 of 15 patients alive and without evidence of disease (66.6%), and 6 of 8 patients alive over 24 months without evidence of disease (75%). We offer a program that for maintenance combined chemotherapy periods should be prolonged to 2-3 or more years.

Adult↗
PubMedDate not supplied

Cystic echinococcosis in semi-nomadic pastoral communities in north-west China.

In order to determine the prevalence of human cystic echinococcosis (CE) in semi-nomadic traditional pastoralist groups in north-west China, 2 large community studies were undertaken in Altai and Tacheng Prefectures in 1990/91 and 1995/96, respectively. The Kekergash community (Altai) comprised mainly ethnic Kazakhs, whereas the Narenhebuke community (Tacheng) comprised mainly Mongolians. Populations were screened for CE by abdominal ultrasound scan (US) and serological tests. The total prevalence of confirmed human CE was higher in Narenhebuke (2.7%, 49/1844) than in Kekergash (0.9%, 17/1861; P < 0.01). Within each community there was no significant difference of CE prevalence between the Kazakh and Mongolian groups, although Han Chinese exhibited twice the rate of CE (4.9%) in Narenhebuke compared to the dominant Mongolian population. For each community, human CE prevalence increased with age and there was a greater risk associated with the practice of home slaughter of livestock. Dogs were screened for Echinococcus granulosus infection and re-infection levels using a highly specific coproantigen test. The proportion of dogs with positive coproantigen tests was significantly higher in Narenhebuke (36.0%, 50/139) compared to Kekergash (17.8%, 16/90). In Narenhebuke the re-infection levels of dogs, as determined by coproantigen positivity, were higher in the winter quarters (49.4%, 39/79) compared to the summer quarters (18.3%, 11/60; P < 0.01). Furthermore, coproantigen re-test positivity was 25% at 3 months and 29.2% at 7 months. Highest dog coproantigen positivity was obtained over the winter period.

Adolescent↗