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Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 1,099 records · Page 61Linked to original sources

Superficial carcinomas of the esophagus and gastric cardia. A clinicopathological analysis of 141 cases.

From January 1970 to June 1992, 141 patients with superficial esophageal and cardiac carcinomas (SEC and SCC) underwent surgical treatment. Of the 141 patients 128(90.8%) had slight symptoms related to swallowing, and the remaining 13(9.2%) were asymptomatic. Balloon cytology and esophagoscopy proved very useful for the diagnosis of SEC and SCC, and Lugol's solution staining technique was an effective auxiliary diagnostic measure. Lymph node metastasis was not found in patients with epithelial (EP) cancer. However, it was present in one (2.9%) of 34 patients with muscularis mucosal (MM) invasion, and in 5 (8.6%) of 58 patients with submucosal (SM) cancer. The 5-year survival rates of the patients with SEC and SCC were 75.5% and 71.4%, respectively (P > 0.05). The different depth of tumor invasion including EP, MM and SM cancers showed significant differences in the 5-year survival rate (P < 0.05). Although the prognosis for the patients with lymph node metastasis is poor, we should advocate extended lymph node dissection in surgical treatment of the patients in whom MM and SM cancers are suspected.

Adenocarcinoma↗

[On-line monitoring of nitrofurantoin in urine of rabbit by a flow-injection system with a fiber-optic chemical sensor].

A flow-injection system for monitoring of nitrofurantoin (NFT) in rabbit urine that makes use of a kind of fiber-optic chemical sensor is presented. The NFT-sensitive optrode was combined with a membrane onto which was immobilized pyrenebutyric acid (PBA) as a fluoroprobe. The NFT concentration was determined via dynamic quenching of the fluorescence of PBA. The average recovery was 96.5%-102.9%. The relative standard deviations for within-day and between-day were 3.1%-3.7% and 1.6%-3.8% respectively. The calibration curve was linear in the range from 2 micrograms.ml-1 to 100 micrograms.ml-1 with r = 0.9983. The detection limit of this method was 0.74 microgram.ml-1. The urine drug concentration-time course in rabbit after oral administration conformed to a one compartment open model with a first order absorption phase. Mean T1/2 value was 0.75 +/- 0.14 h. The selectivity was affirmed by HPTLC.

Animals↗

Expression of MHC-I and MHC-II antigens in endomyocardial biopsies from patients with viral myocarditis and cardiomyopathy.

In situ expression of major histocompatibility complex (MHC) I and II antigens were examined in endomyocardial biopsy samples from 35 patients with viral myocarditis (VMC) and dilated cardiomyopathy (DCM). Increased expressions of these 2 antigens were observed on endocardia, capillary endothelia, dentritic and mononuclear cell membranes. The expression of sarcolemma was also found in specimens of VMC and DCM. Thus the abnormal expression of MHC is a new marker of autoimmune reactivity directed against cardiac structures.

Adolescent↗

[Observation on the animal model of hypoxic-ischemic encephalopathy and the change of pathology in newborn pigs].

Thirty newborn pigs within 3 days of life were randomly divided into different groups according to the time of hypoxic-ischemic encephalopathy. The results showed that the brain damage and pathologic changes were most obvious in the 60 min hypoxia-ischemic group. Brain edema was observed in every group, especially in the group where hypoxia-ischemic lasted for more than 30 min. Cerebromalacia and hemorrhage in ventricles of brain and in arachnoid were observed, and these were particularly noticed in the group where hypoxia-ischemia lasted for 60 min.

Animals↗

[An investigation and design of apparatus for measuring fetal lung maturity].

Clinically, the authorized method for determing fetal lung maturity is the measurement of the ratio of surface-active L/S in amniotic fluid. To set up new, simple, rapid and accurate method, an apparatus for measuring fetal lung maturity was made. The paper describes the basic principle and working procedure of the apparatus. 148 amniotic fluid specimens from different pregnancies were measured by means of the apparatus. The result was compared with the L/S. The sensitivity of measurement was 95%, specificity 91%, and accuracy 93%. The operation of the apparatus is simple, convenient and rapid. A small quantity of amniotic fluid is needed. In conclusion, the expected result was attained. The apparatus is of great importance to clinical application.

Amniotic Fluid↗

[Detection of human cytomegalovirus DNA in vascular plaques of atherosclerosis by in situ hybridization].

To examine the possible role of HCMV in the etiology of atherosclerosis, we searched for the presence of HCMV DNA in arterial vascular tissues by in situ hybridization. Biotin labelled HCMV DNA probe was used on specimens of arterial wall taken from patients with clinically significant atherosclerosis. Evidence for the presence of HCMV DNA was obtained in 13 specimens out of 32 atherosclerosis specimens. In contrast, only 1 specimen was positive in the control group (Total 15 specimens of normal arterial and venous wall), suggesting that there is a close relationship between human cytomegalovirus infection and atherosclerosis development. The results also showed that the positive hybridization signals were mainly observed in the nuclei of smooth muscular cells, rarely found in outer layer of arterial walls, cell membrane and cytoplasm. It was indicating that HCMV infection might be an etiological agent in the development of atherosclerosis.

Adult↗

[Preliminary study on early fibrosis of chronic hepatitis B treated with Ginkgo biloba Composita].

The purpose of this paper was to study the effect of Ginkgo biloba Composita (GBC) on liver collagen fibrosis. The 86 patients were suffering from chronic persistent and active hepatitis B with early fibrosis confirmed by liver biopsy. Serum pro-collagen-III-peptide (PIIIP), laminin (LN), superoxide dismutase (SOD), malonyldialdehyde (MDA) were determined and some patients' biopsies examined with light and electron microscope before and after treatment were observed. By the end of 3 months, the results showed that PIIIP, LN, SOD, MDA were significantly decreased after GBC treatment (P < 0.01) and liver fibrosis of patients was partly reabsorbed and had remission. It was suggested that GBC was effective in arresting the development of liver fibrosis of chronic hepatitis.

Adult↗

[Posterior chamber intraocular lens implantation in the absence of posterior capsular support].

The authors retrospectively studied the clinical records of 15 eyes without posterior capsular support receiving transscleral ciliary sulcus fixation of posterior chamber intraocular lenses. Postoperative followup period range from 2 weeks to 8 months, an average of 2.2 months. Postoperative visual acuity improved in all patients, 20% of which had 0.6 or better and 40%-between 0.2 and 0.5. Lens rotation was the primary complication and accounted for poor acuity in some cases. The results indicate that ciliary sulcus fixation in the absence of posterior capsular support appears to be safe and effective and may represent a significant advance in anterior segment surgery.

Adolescent↗

[Hemodynamic changes in portal system after transjugular intrahepatic portosystemic shunts (TIPS)].

In this study portal venous flow (PVF), splenic venous flow (SPVF), hepatic artery volume (HAV), and portal pressure were measured before and after TIPS in 11 patients with portal hypertension. The results were compared with those of normal controls. In the normal controls PVF averaged 947.2 +/- 133.4ml/min, SPVF 239.6 +/- 116.3ml/min, and HAV 241.6 +/- 78.8ml/min. In the TIPS group before and after TIPS, PVF was 883.2 +/- 233.4ml/min vs. 958.7 +/- 185.2ml/min; SPVF was 448.9 +/- 111.6ml/min vs. 333.1 +/- 101.5ml/min; HVP was 225.3 +/- 122.7ml/min vs. 249.3 +/- 103.8ml/min. Portal pressure dropped from 3.94kPa +/- 0.46 to 2.52 +/- 0.60kPa after TIPS. We conclude that in patients after TIPS portal pressure drops blood flow in the truck of the portal vein increases, flow of hepatic tissue decreases, and blood flow in splenic vein decreases. Blood flow in hepatic aftery was not significantly changed.

Adult↗

An evaluation on smoking-induced health costs in China (1988-1989).

A study on smoking-attributable health economic costs in China was conducted from 1988-1992, in which three major categories of chronic diseases, diseases of cancer, diseases of circulatory system, and diseases of respiratory system were included. A prevalence-based method which estimated the cumulative effect of cigarette smoking during the past 20-30 years was used. The results show that in 1989, the total smoking-attributable economic costs to health sectors in China were about 27.1 billion of Chinese Yuan, including about 7 billion Yuan in direct medical costs and 20 billion Yuan in indirect costs, which include indirect morbidity costs and indirect mortality costs. The relatively low direct costs reflected the low medical costs at hospitals in China at that time. And the high proportion of indirect costs relative to the total costs shows the high potential years of life lost due to cigarette smoking. The results also show the heavier health burden in urban areas than in rural areas, reflecting the worse situation in urban China at nowadays. But if considering that almost 80% of the Chinese are rural farmers with the higher smoking prevalence and relatively shorter history of manufactured cigarette smoking than their urban counterparts, the very frightful situation due to cigarette smoking would be for China in the next century.

Cardiovascular Diseases↗

[Anatomic structure of the soft tissue of nasal dorsum and its applications in augmentation rhinoplasty].

The nasalis--procerus aponeurosis and its clinical applications in augmentation rhinoplasty were described in this paper. According to our experience, the silicone frame can be put in three anatomical layers of the nasal dorsum for augmentation. The paper showed the manipulating points and problems of the operations done through various anatomical layer, and also pointed out that good results can be obtained with the silicone frame being put on or beneath the nasalis--procerus aponeurosis.

Adult↗

Study on motor functions of antrum after highly selective vagotomy (HSV) plus mucosal antrectomy.

To elucidate the effects of highly selective vagotomy plus mucosal antrectomy (HSV-MA) antral functions, eighteen dogs were randomly divided into control, HSV and HSV-MA group for determining gastric emptying, antral myoelectric activity and antral pressure. The tests were performed 4 months after operation in the HSV-MA and HSV group. By roentgenoscopy, the gastric and duodenal shape were normal, and gastric peristalsis was clearly seen in all the dogs in the three groups. The beginning and ending time of gastric emptying in the HSV-MA group were 5.0 +/- 0.06 minutes and 4.0 +/- 0.4 hours respectively, which were similar to those in the control and HSV group (P > 0.05). The frequency of antral myoelectric action potential in the HSV-MA group (3.11 +/- 0.65 cycles/minutes) was significantly lower than those in the control and HSV group (P < 0.05). Intramuscular injection of pentagastrin significantly increased the frequency of antral myoelectric action potential (P < 0.01) in all groups, and eliminated the difference among them before the injection. The antral pressure wave occurred immediately following the antral myoelectric action potential waves. The antral pressure values in the control and HSV-MA group were similar (P > 0.05), and were significantly lower than that in the HSV group (P < 0.05). Intramuscular injection of pentagastrin significantly increased the antral pressure (P < 0.001) in all groups and eliminated the difference among them before the injection. These evidences suggest that the motor function of the reconstructed antrum following HSV-MA nearly reached normal level despite a lower antral myoelectric frequency. Combined with other reports, HSV-MA has a good clinical prospect as an operation for the treatment of chronic duodenal ulcer.

Action Potentials↗

[Anatomical and histological observation on soft tissue of nasal dorsum and the nasalis-procerus aponeurosis].

26 nasal specimens of cadavers were studied with anatomical and histological methods. Two layers of collagen fibre arranged in different pattern were found beneath the nasalis transversus and procerus. The superficial layer of compact collagen fibres directly attached to and wraped up nasalis transversus and procerus, and it was named the nasalis-procerus aponeurosis; the deep layer of relatively flexible collagen fibres was loose subaponeuratic tissue. The study showed that soft tissue of nasal dorsum could be divided into four layers; skin, superficial fascia, skeletal muscle and aponeurosis, and loose subaponeurotic tissue. This result provides scientific basis for proper design of rhinoplasty.

Adult↗

[Detection of estrogen receptor messenger ribonucleic acid in normal and ovariectomized rat bone].

Using ovariectomized female SD rats (OVX) as animal osteoporosis models, RNA samples were extracted directly from rat bone. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to examine the estrogen receptor (ER) messenger RNA (mRNA) level of expression in normal and OVX rat bone tissue. Results demonstrated that the rat ER gene is expressed in normal rat bone. DNA sequencing showed 300 bases sequence. We found that the OVX rats showed a sharp decrease in ER mRNA level when estrogen was reduced after ovariectomy and the expression of bone ER mRNA increased during estradiol therapy, suggesting that the expression of bone ER mRNA relies upon the level of estrogen. In addition, ER plays a very important role in the pathogenesis by means of its gene regulatory functions.

Animals↗

The Saccharomyces cerevisiae FKS1 (ETG1) gene encodes an integral membrane protein which is a subunit of 1,3-beta-D-glucan synthase.

In Saccharomyces cerevisiae, mutations in FKS1 confer hypersensitivity to the immunosuppressants FK506 and cyclosporin A, while mutations in ETG1 confer resistance to the cell-wall-active echinocandins (inhibitors of 1,3-beta-D-glucan synthase) and, in some cases, concomitant hypersensitivity to the chitin synthase inhibitor nikkomycin Z. The FKS1 and ETG1 genes were cloned by complementation of these phenotypes and were found to be identical. Disruption of the gene results in (i) a pronounced slow-growth phenotype, (ii) hypersensitivity to FK506 and cyclosporin A, (iii) a slight increase in sensitivity to echinocandin, and (iv) a significant reduction in 1,3-beta-D-glucan synthase activity in vitro. The nucleotide sequence encodes a 215-kDa polypeptide predicted to be an integral membrane protein with 16 transmembrane helices, consistent with previous observations that the etg1-1 mutation results in echinocandin-resistant glucan synthase activity associated with the nonextractable membrane fraction of the enzyme. These results suggest that FKS1 encodes a subunit of 1,3-beta-D-glucan synthase. The residual activity present in the disruption mutant, the nonessential nature of the gene, and results of Southern blot hybridization analysis point to the existence of a glucan synthase isozyme.

Base Sequence↗

Chimeric (mouse/human) anti-colon cancer antibody c30.6 inhibits the growth of human colorectal cancer xenografts in scid/scid mice.

The mouse monoclonal antibody, m30.6 (IgG2b), detects an antigenic determinant expressed predominantly on the surface of colorectal adenocarcinoma cells and has been shown previously to be a potentially useful therapeutic and diagnostic reagent for human colon cancer. We report the production and characterization of a mouse/human chimeric antibody, c30.6, with potent in vitro and in vivo antitumor activity. The genes encoding the variable domains for heavy and light chains were amplified by thermal cycling using degenerate oligonucleotide primers complementary to conserved immunoglobulin framework sequences. The gene segments were sequenced, subcloned into eukaryotic expression vectors containing human constant region genes (IgG1 and kappa), and cotransfected into nonsecreting Sp2/0 mouse myeloma cells. There were significant differences in the biological activities of the murine and chimeric antibodies. The i.p. administration of c30.6 but not of m30.6 produced a marked growth inhibition of s.c. 30.6+ COLO 205 tumors in scid/scid mice (approximately 40% reduction in tumor size, measured 21 days after tumor inoculation). Reduced tumor growth was not due to altered binding characteristics of c30.6 because: (a) the chimeric antibody was shown by flow cytometry to bind exclusively to cell lines that expressed the 30.6 determinant; (b) c30.6 was able to completely inhibit the binding of m30.6 on 30.6+ cells; and (c) the affinity of binding of the two antibodies was the same (Ka, approximately 1.50 x 10(8)). Up to 15% of the total injected antibody dose/g tissue was localized in 30.6+ tumors at 24 h, approximately 13% was present in the tumors at 48 h, and approximately 10% was present at 72 h. Furthermore, c30.6 demonstrated a shorter circulating half-life (53 h; m30.6, 72 h) when given i.p. to C57BL6 x BALB/cF1 mice. Unlike m30.6, c30.6 was also strongly active in antibody-dependent cell-mediated cytotoxicity against a range of 30.6+ tumor target cells in vitro. Up to 80% specific 51Cr release was achieved using either freshly isolated human peripheral blood mononuclear cells or 2-day-old interleukin 2-stimulated human peripheral blood mononuclear cells as effectors. The enhanced antitumor activity of c30.6 suggests that it might be a useful immunotherapeutic reagent for colorectal carcinoma.

Adenocarcinoma↗

Concordance of smooth pursuit and saccadic measures in normal monozygotic twin pairs.

Although the range of normal ocular motor performance is broad, little is known about the sources of variability. Genetic transmission of eye movement deficits has been described but such possible control of normal function has been little investigated. Characteristics of smooth pursuit and saccades can be examined for the degree of concordance in related individuals. In this pilot study, we studied saccades and pursuit in eight monozygotic (MZ) twin pairs. The statistical analysis of the data used the intraclass correlation of MZ twins (rMZ) to estimate what fraction the covariance of the twin pairs was of the population variance. All saccadic measures showed significant MZ correlations (p < 0.05). Smooth pursuit gains were even more highly correlated (p < 0.001). These results indicate considerable similarity within pairs of twins, particularly for horizontal smooth pursuit, and suggest that larger studies on monozygotic and dizygotic twins would be desirable, to help separate out the relative contributions of environmental and genetic factors.

Adult↗