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Biomedical subjects

S Z Li

Publications and source records attributed to S Z Li.

At least 19 recordsLinked to original sources
PubMed1992

[Synthesis and radiosensitizing activity of benzimidazoles].

In search for effective radiosensitizer with low neurotoxicity, benzimidazole compounds were synthesized. Reaction of 2-nitrobenzimidazole with ethyl chloroformate yielded ethyl alpha-(2-nitrobenzimidazolyl-1)-formate(1) or ethyl alpha-(2-hydroxybenzimidazolyl-1)-formate(2), depending upon the solvents used. Reaction of 2-nitrobenzimidazole with 1,2-epoxy-3-chloropropane gave a cyclized compound which was confirmed to be benzimidazo(1,2b)-5'-chloromethyl-oxazolidine(3). In attempt to increase hydrophilicity, 1-substituted 2(3'-pyridyl)-5-nitrobenzimidazoles were prepared by reaction of 2-(3'-pyridyl)-5(6)-nitrobenzimidazole(4) with alkyl epoxides or ethyl chloroacetate. Some of the compounds synthesized were tested for radiosensitizing activity in Ehrlich ascites carcinoma-bearing mice. Preliminary results showed that some compounds have radiosensitizing activity. The radiosensitizing enhancement ratio (SER) of compounds 3, 5 and 6 were found to be 1.50, 1.52 and 1.65 respectively.

Animals↗
PubMed1991

Doppler echocardiographic evaluation of pulmonary artery pressure in pneumonia of infants and children.

Previously, there was insufficient evidence to confirm that pneumonia in infants and children might lead to the development of pulmonary hypertension. Recently, it has been shown that acceleration time corrected for heart rate (ATc) and the ratios of right ventricular preejection period to right ventricular ejection time (RPEP/RVET) and of right ventricular preejection period to acceleration time (RPEP/AT) derived from Doppler echocardiography correlated well with pulmonary artery pressure (PAP). To approach PAP in patients with infantile pneumonia, we measured RPEP/RVET, RPEP/AT, and ATc in 105 infants and children with pneumonia and in 17 controls, using a commercially available 2-dimensional echocardiograph (Toshiba SSH-40A) with SDS-21B Doppler unit. An increase of varying degrees in both ratios and ATc was noted during acute illness and significant differences in ratios RPEP/RVET and RPEP/AT were found among patients with mild, moderate, and severe disease. This suggested that PAP increased to different extents in the acute stage of illness and that the degree of increase was related to the severity of disease.

Blood Pressure↗
PubMed1991

[Studies on the structure of gnetifolin A of Gnetum parvifolium (Warb.) C.Y. Cheng].

A new component, gnetifolin A, was isolated from the ethyl acetate fraction of the stem of Gnetum parvifolium (Warb.) C.Y. Cheng together with three known components isorhapontigenin, resveratrol and beta-sitosterol. The structure of gnetifolin A has been established as 2-(3',5'-dihydroxy-4'-methoxyphenyl)-3-methoxy-5-hydroxybenzofuran by spectroscopic methods (UV, IR, MS, 1HNMR, 13CNMR, 2D-NMR).

Benzofurans↗
PubMed1990

Transcriptional down-regulation of the rearranged C-myc expression in murine cell hybrids between a plasmacytoma and a T-cell lymphoma.

Regulation of the rearranged and non-rearranged c-myc expression was studied in murine cell hybrids (SBWI and SBWII) between plasmacytoma (S194) and T-cell lymphoma (BW5147) cells. Expression of the rearranged c-myc of heterogeneous mRNA sizes (1.8 approximately 2.4 kb) was markedly down-regulated in these hybrids regardless of retention of the gene. On the other hand, expression of the non-rearranged c-myc (2.4 kb) was not significantly affected in these hybrids. Treatment of SBWI hybrid cells with cycloheximide enhanced the non-rearranged c-myc 2- to 4-fold but did not release the down-regulation of the rearranged c-myc at all, suggesting that the down-regulation of the rearranged c-myc in the hybrid cells was mainly at a transcriptional rather than a post-transcriptional level. This was supported by the results of nuclear run-on assay: the high level of run-on transcripts in S194 cells declined in SBWI hybrid cells comparable to the level in BW5147 cells. The rearranged c-myc was hemi-methylated in S194 cells and the pattern was the same in SBWI hybrid cells. Furthermore, down-regulation of the rearranged c-myc in the hybrid was also not restored by treatment with 5-azacytidine (5-AzaC), 12-O-tetradecanoylphorbol-13-acetate (TPA) or forskolin, suggesting no causative involvement of DNA methylation or protein phosphorylation in down-regulation. Higher DNase I sensitivity of the rearranged c-myc in S194 cells decreased to a similar extent to that of the non-rearranged c-myc after cell fusion with BW5147 cells. These results suggest that expression of the rearranged c-myc is down-regulated at the level of transcription in murine cell hybrids between a plasmacytoma and a T-cell lymphoma, probably by changing chromatin configuration around the gene from the open to the closed state.

Animals↗
PubMed1990

[Vitreous loss and the incidence of cystoid macular edema].

81 patients (81 eyes) with senile cataract were performed intracapsular cataract extraction, and fluorescein angiography 1 to 6 months postoperative revealed the incidence of cystoid macular edema to be 68% (21/31 eyes) in cataract extractions with vitreous loss and 14% (7/50 eyes) in those without, the difference between the 2 groups was very significant (P less than 0.01).

Aged↗
PubMed1989

Regional mapping of the FOS oncogene to rat chromosome 6q21----q23.

Using a panel of rat x mouse somatic cell hybrids and in situ hybridization, we determined the chromosomal location of the rat FOS gene locus. Southern blot analysis assigned this oncogene to rat chromosome 6. In situ hybridization confirmed this finding and mapped the gene more precisely to 6q21----q2.

Animals↗
PubMed1989

Humoral and cellular immune responses to lens protein in patients with congenital cataract.

In order to understand the immune responses to lens protein in patients with congenital cataract, the passive hemagglutination assay for humoral immunity and the leukocyte migration test for cellular immunity to lens protein were performed on 43 patients with congenital cataract and 30 healthy persons served as control. The results showed that there was no significant difference in the incidence of humoral immune responses to lens protein between patients with congenital cataract and the controls (P greater than 0.05), but the incidence of cellular immune responses to lens protein in patients with congenital cataract was higher than that of the controls (P less than 0.005). The results of this study suggested that during the development of congenital cataract, lens protein leaked into the aqueous humour and entered the systemic circulation, sensitizing lymphocytes and producing cellular mediated immune responses. Further investigation is necessary to determine whether there is any relationship between the immune responses to lens protein and the formation of congenital cataract.

Adolescent↗
PubMed1989

[Ocular findings in multiple sclerosis].

13 (59%) of 22 cases of confirmed multiple sclerosis were of acute or subacute onset and 12 cases (18 eyes) had acute retrobulbar neuritis with acute visual impairment as the initial symptom. During the course of disease, other ocular complaints occurred, such as ptosis, diplopia, nystagmus, pupil signs, visual field defects, or optic nerve disorders. The initial symptoms, clinical manifestations, morbid course, diagnosis, and pathological findings were also touched upon.

Adolescent↗
PubMed1989

[Treatment of congenital cataract with McIntyre co-axial I.A. cannula].

Thirty seven eyes with congenital cataract in with there a lot of transparent cortex were treated with McIntyre co-axial cannula. Primary posterior capsuloctomy after removing the cortex was performed on patients aged less 3 years; for patients over 3 years, their posterior capsule remained intact. After the operation, all cases got transparent pupillary space more than 5 mm in diameter. The visual acuities improved in 32 eyes and remained unchanged in 5 eyes. This procedure not only received satisfactory results, but also avoided side effects caused by capsuloctomy and reduced the possibility of general anesthesia accident and operation fee.

Cataract↗
PubMed1989

[Early ocular hypertension after cataract extraction].

The intraocular pressure (IOP) course during the first postoperative month was measured with Goldmann applanation tonometry in 93 eyes. The patients include 30 eyes of intracapsular cataract extraction (ICCE), 32 eyes of extracapsular cataract extraction (ECCE) and 31 eyes of ECCE combined with posterior chamber intraocular lens (PC-IOL) implantation. The preoperative average IOP was 13.30 +/- 3.24 mmHg in 93 eyes. The first day after cataract extraction was 25.33 +/- 8.18 mmHg and 59 eyes (63.44%) had an IOP higher than 23 mmHg. On the second day it was 16.03 +/- 7.54 mmHg. On the third day it was 14.69 +/- 5.45 mmHg. On the seventh day it was 13.32 +/- 3.44 mmHg and only 2 eyes (2.14%) IOP was higher than 23 mmHg. The first postoperative month average IOP was 12.93 +/- 1.31 mmHg and it was above 23 mmHg in only one eye. When compared with preoperation a significant increase in IOP was found postoperatively. But on the seventh day and after the first month there was no significant difference (P greater than 0.05). The IOP rise among ICCE group, ECCE group and PC-IOL group did not differ significantly.

Adult↗
PubMed1989

[Clinical and experimental observations of jinqiancao gao on preventive and therapeutic effects in cholelithiasis].

This paper reports the clinical treatment of 120 patients with cholelithiasis for 2 months with Jinquiancao Gao. The Results showed that the clinical effective rate was 92.5%, among which 29 cases were cured, 42 cases markedly improved and 40 cases ineffective. Animal experiments showed that this medicine can prevent gallstone growth. The gallstone growth rate was 78.5% in the control group and 42.8% in the experimental group (P less than 0.05). The mechanism of the decrease of gallstone growth rate suggests that the said medicine could inhibit the activity of beta-Glucuronidase in the bile, diminish the non-combined bilirubin and prevent the bile from forming bilirubin stones. The result of cultured liver cells in vitro showed that the cholesterol synthesis was markedly inhibited by Jinqiancao Gao. Thus the cholesterol concentration of bile was decreased. These effects in turn prevented the bile from forming cholesterol stones.

Adult↗
PubMed1988

Iris inflammatory cells, fibronectin, fibrinogen, and immunoglobulin in various ocular diseases.

Using immunohistochemical techniques, we analyzed the inflammatory cell subpopulation and the presence of fibronectin and immunoglobulin in iridectomy specimens from 50 patients with cataracts, glaucoma, and uveitis, and from ten normal eyes. The irises from patients with uveitis showed the highest numbers of T-lymphocytic infiltration compared with all other groups. Concentrations of fibronectin, fibrinogen, and immunoglobulins were significantly higher in the uveitic group compared with other diseases and normal controls. The irises from patients with glaucoma showed fewer infiltrating cells and less fibronectin and fibrinogen. Enhancement of major histocompatibility complex class II antigen HLA-DR expression was observed in all disease groups compared with controls. These findings suggest that in patients with uveitis and acute glaucoma the infiltrating T lymphocytes and the presence of fibronectin, fibrinogen, and immunoglobulins may contribute to the greater risk of postsurgical inflammation, leading to such problems as closure of the iridectomy. The enhancement of HLA-DR antigen expression in the iris may indicate abnormalities of iris resident cells seen in various diseases.

Aged↗
PubMed1988

[Effect of combined transfer of irradiated allo-lymphocytes and LAK cells on pulmonary metastasis of mammary carcinoma (SST-2) in SHR rats].

We have attempted to prevent and treat experimental pulmonary metastasis of a rat mammary carcinoma (SST-2) by adopting transfer of LAK cells and irradiated allogeneic spleen cells (as an allogeneic immune stimulator). Transfer experiments were carried out by the following schedule: SST-2 cells were inoculated intravenously on day 0, irradiated allogeneic spleen cells were transferred intravenously on day -5, 1 and 8, and LAK cells were transferred on day 2, 5 and 7. In the control groups: the average number of metastatic nodules in the lungs were 180.5, 62.0, 10.2 in the groups of allogeneic lymphocytes alone and LAK cells alone in experiment 1, and 81.2, 21.0, 3.8 in experiment 2, respectively. In the combined transfer group, the average metastatic nodules were 1.3 in experiment 1 and 0 in experiment 2, and 17 out of the total 20 rats were completely free from metastasis. Interleukine 2 (IL-2) level in the serum increased gradually and reached a peak on day 3 and thereafter, declined after the 2nd transfer of allogeneic lymphocytes. We postulate that allogeneic lymphocytes transferred are able to stimulate a release of endogenous IL-2 which supports and augments antitumor activity of LAK cells.

Animals↗