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Biomedical subjects

S L Li

Publications and source records attributed to S L Li.

At least 91 records · Page 5Linked to original sources
PubMed1990

Functional characteristics of the intercellular adhesion molecule-1 (CD54) expressed on cytotoxic human blood lymphocytes.

We have shown that intercellular adhesion molecule-1 (ICAM-1) (CD54) positive cells are mainly responsible for the natural cytotoxic function of human blood lymphocytes. The evidences were the inhibition of cytotoxicity by anti-ICAM-1 (LB-2) monoclonal antibodies (mAb) and the loss of lytic activity after removal of the ICAM-1+ cells. In addition, the cytotoxic potential of the separated ICAM-1- lymphocyte population after activation appeared in parallel with the expression of this molecule. The ICAM-1+ lymphocytes lysed both LFA-1 (CD11a/CD18 or Leu-CAMa) positive and negative cell lines, and pretreatment of the effectors with the LB-2 mAb also inhibited the lysis of LFA-1- targets. The results point to a yet unrecognized role of ICAM-1 on the lymphocytes. Kinetics experiments suggested that pretreatment of lymphocytes with alpha-ICAM-1 (LB-2) mAb did not inhibit the promptly established lytic interactions but influenced later events, recycling and/or recruitment of effectors. It is possible that the cytotoxic potential is regulated by contacts between the members of the lymphocyte population and that these events occur via their ICAM-1 and LFA-1. Exposure of lymphocytes to NK-sensitive targets for 16 hr elevated their cytotoxic potential. The function of activated lymphocytes was not inhibited by the LB-2 mAb.

Antibodies, Monoclonal↗
PubMed1990

Molecular cloning and nucleotide sequence of the beta-lytic protease gene from Achromobacter lyticus.

Two bacteriolytic enzymes secreted by Achromobacter lyticus M497-1 were purified and identified as being very similar (considering their amino acid composition and N-terminal sequence) to alpha- and beta-lytic proteases from Lysobacter enzymogenes. A 1.8-kb EcoRI fragment containing the structural gene for beta-lytic protease was cloned from A. lyticus chromosomal DNA. The protein sequence deduced from the nucleotide sequence was identical to the known sequence of beta-lytic protease, except for six residues. The nucleotide sequence revealed that the mature enzyme is composed of 179 amino acid residues with an additional 195 amino acids at the amino-terminal end of the enzyme, which includes the signal peptide, thus indicating that the enzyme is synthesized as a precursor protein.

Alcaligenes↗
PubMed1990

Malignant lymphomas in cynomolgus monkeys infected with simian immunodeficiency virus.

Malignant lymphomas were observed in 38% (9 of 24) of simian immunodeficiency virus (SIV)-infected cynomolgus monkeys (Macaca fascicularis) 5 to 15 months after inoculation with SIV strain SMM3. Lymphomagenesis in the SIV-infected monkeys was not related directly to the SIV-infectious dose given. All SIV-infected animals developed severe immunodeficiency. No significant difference in immunodeficiency was observed between tumor-bearing and non-tumor-bearing animals. In contrast, no lymphomas were observed in a comparable group of HIV-2-infected monkeys, which did not develop immunodeficiency; nor did the noninfected control monkeys. All 9 SIV-related tumors were high-grade B-cell lymphoblastic or pleomorphic lymphomas with extranodal, disseminated growth. Most tumors showed marked infiltration by monocytes and CD8+ T lymphocytes. Occasional tumor infiltrating cells showed immunohistochemical reaction for SIV. The cells of two tumors were established in vitro and shown to be of B-cell phenotype. The tumor cell cultures showed no reverse transcriptase activity and no evidence of virus infection by electron microscopy. Our observations indicate that SIV-induced immunodeficiency in cynomolgus monkeys also mimics HIV infection and AIDS in humans with regard to increased lymphomagenesis and type of lymphomas.

Animals↗
PubMed1990

[Diagnostic significance of the cuticular patterns on leaf surface of Sarcandra glabra].

The cuticular patterns on leaf surface of Sarcandra glabra (Thunb.) Nakai were studied with scanning electron microscope. It was found that the cuticular patterns vary not only with the district of specimen collection, but also with the developmental stage of the leaf. The characteristics of the cuticular patterns are described in detail with 2 plates of illustrations.

Medicine, Chinese Traditional↗
PubMed1990

Study on the protoplast fusion between a thermotolerant yeast and Saccharomyces cerevisiae.

Intergenetic protoplast fusion between Saccharomyces cerevisiae 396 and thermotolerant yeast Candida sp. C6 has been studied. 396 is a molasses distiller's yeast, and C6 which was isolated from the hot spring in Yunnan, grows well at 45 degrees C. The auxotrophic mutants of 396 (Arg.) and C6 (Lys.) were obtained by treatment of NTG. The fusion frequency was 0.91 per 10(5) protoplasts. Six fusants were studied, the average size of their cells is 1.3 times the size of their parents, while the DNA content is 1.6 times. Other characteristics of the fusants including colonial and cell morphology, physiology, especially in carbon sources assimilation appeared different. The possibility of heterokaryon formation was excluded except for F2 and F14. The growth curves, efficiency of sugar utilization and ethanol yield of original parents 396 and C6, immediate parents 396 (Arg.) and C6 (Lys.), fusants F1, F7, F12 and F13 have been compared at 28 degrees C, 40 degrees C and 45 degrees C. The intergenetic fusant F13 with efficiency of substrate utilization 94.3% and the final ethanol concentration 59.7 g/l at 40 degrees C has been selected.

Candida↗
PubMed1990

Dynamic study on iliac trabeculae of normal Chinese.

We studied 41 iliac bone blocks taken by biopsies from normal Chinese who were divided into several groups by age. On the schedule of 3-11-3-5 days, double tetracycline labellings were administered before bone biopsies. Ten microns undecalcified sections were made with Reichert-Jung microtome and analyzed with Zeizz MOP-Videoplan by light and fluorescent microscopy. The results showed that bone formation had a peak value at adolescence and the mean wall thickness decreased gradually with age. Bone dynamics fluctuated with age because of endocrinological changes in the intrinsic environment. The data we obtained may be used as a reference for clinical investigation of various metabolic bone disorders.

Adult↗
PubMed1990

[Establishment of a human cancer cell line from adenoid cystic carcinoma of the minor salivary gland].

This paper reports the establishment of a human cancer cell line from adenoid cystic carcinoma of the minor salivary gland and the study of its biological behaviours. The cells of the cell line (SACC-83) are polygonal in shape, with a mosaic arrangement. Ultrastructural study reveals that many secretory granules are present in the cytoplasm. The mitosis index, growth curve, chromosome analysis and transplantation into nude mice were performed and discussed. The results prove that this cell line possesses the morphological and biological features of adenoid cystic carcinoma.

Adult↗
PubMed1989

[Development and pharmacokinetic study of metoprolol tartrate controlled-release tablet remaining-floating in stomach].

An oral controlled-release system (M-HBS) of metoprolol was developed based on the hydrodynamically balanced controlled drug delivery system. It was found that the in vitro release characteristics showed basically first-order kinetics (K'r = 0.1651 h-1); a tentative two-year expiration date on M-HBS was established; the gamma-scintiphotographic study after oral ingestion showed that M-HBS was retained in human stomach for longer time (5-6 h) than the conventional metoprolol tablet (1-1.5 h). The blood concentration-time course of M-HBS was demonstrated to fit a one-compartment model with apparent first order absorption and first order elimination. The parameters were calculated using a NONLIN computer program with the values of Ka, K, Vd, tmax, cmax, being 0.1944 h-1, 0.1867 h-1, 2.813, 5.247 h, 125.1 ng/ml, respectively. Moreover, the fraction of the dose absorbed from M-HBS in vivo well correlated with dissolution rate in vitro.

Adult↗
PubMed1989

[Mebendazole-medicated-salt in the control of hookworm infection].

From 1984-1987, mass application of mebendazole-medicated salt was studied for the control of hookworm infection in 5 pilot areas (Wuming, Shanlin, Bobai, Guilin and Rongxian Counties) in Guangxi Zhuang Autonomous Region. The dosages of mebendazole (mixed with salt) administered were 15mg, 25mg, 30mg, 40mg, 50mg, 30mg, 70mg, 80mg, 100mg or 200mg per person per day for 15, 20 or 30 days. The results showed that 40mg/day for 15-20 days could result in stool egg negative conversion rates of 92.3 to 94.4%, while 50mg/day for 30 days resulted in 96.9 to 100%. Concurrently, the hookworm infection rate in pilot areas dropped by 57.9-71.7% in a short time; whereas the stool egg negative conversion rate of Ascaris lumbricoides was as high as 99.1% to 100% at the same dosage, when the dosage of 100mg/day for 30 days was given, the egg negative reversion rate for Trichuris trichiura was 97.6%. Promising result was also recorded concerning the tolerance of the medicated salt, as the side effects in the inhabitants were mild. In conclusion, the authors considered that the application of mebendazole-medicated salt was a simple and effective measure in controlling hookworm infection, especially in the light of solving the problem of incomplete mass detection and selected mass treatment. Furthermore, it is much more economic from the cost-effect point of view.

Female↗
PubMed1987

Planned simple carotid resection in surgery of paraganglioma fixed to the carotid artery.

Of 25 surgically treated cases (1956-1986) of paraganglioma, eleven underwent simple carotid resection. The collateral cerebral crossflow was promoted preoperatively with the use of compressing exercises of the carotid artery and controlled by rheoencephalography. There was no operative mortality. One died with a malignant lesion, and nine survived 3 months to 21 years without cerebrovascular complications. It appears that this procedure is worthwhile in selected cases.

Acupuncture Therapy↗
PubMed1985

Functional tracheoesophageal shunt for vocal rehabilitation after laryngectomy.

A new one-stage surgical technique for postlaryngectomy vocal rehabilitation was applied to 19 patients with advanced carcinoma of the larynx. The technique consists mainly of the construction of a tracheoesophageal shunt and the creation of a tracheoesophageal flap to cover the shunt preventing entry of food into the trachea. Fifteen of the 19 patients developed useful speech. Slight leakage of liquids into the trachea occurred in four patients. This is avoided by having the patient bend his head down during deglutition. This technique can be performed in a wide variety of clinical situations and restores effortless speech without any special training.

Adult↗
PubMed1985

Morphological and functional investigations on macrophages with heterogeneous fluorescent staining.

Four heterogeneous colors of fluorescence were demonstrated in macrophages from rabbit lymph nodes and mouse peritoneal exudate using fluorescent staining. They were bright blue, light blue, bluish green and yellow colors of fluorescence respectively. All of these 4 types of macrophages with heterogeneous colors of fluorescence could form EA or EAC rosettes and were able to phagocytose chicken erythrocytes and ink carbon granules. Among them the macrophages with bright blue color of fluorescence could form large EA or EAC rosettes and showed more rapid and stronger activity to phagocytose chicken erythrocytes, while those with bluish green and yellow colors of fluorescence showed stronger activity to phagocytose ink carbon granules.

Animals↗
PubMed1981

The triphasic reduction of cytochrome b in the succinate-cytochrome c reductase.

In the succinate-cytochrome c reductase, the reduction of cytochrome b has been found to be triphasic: an initial rapid partial reduction was followed first by a rapid oxidation and then finally by a slow reduction. The initial reduction of cytochrome b was faster than that of cytochrome c1 and the final slow reduction of cytochrome b began when cytochrome c1 reduction was approaching completion. In presence of the inhibitors antimycin A or HQNO the reduction of cytochrome b became monophasic. Hysteresis or a kinetic cooperative effect of a factor controlling cytochrome b oxidation has been suggested as a possible explanation for the triphasic reduction of cytochrome b.

Animals↗