Search PubMed⌕ Search

Biomedical subjects

D S Wang

Publications and source records attributed to D S Wang.

At least 91 records · Page 5Linked to original sources
PubMed1993

Expression levels of IL-6 mRNA in PBMNCs from patients with IDDM, NIDDM and normals by RT-PCR procedure.

Although it has been confirmed that insulin dependent diabetes mellitus (IDDM) is a kind of autoimmune disease, islet cell autoantibodies (ICAs), insulin autoantibodies (IAA) and anti-GAD-glutamic acid decardaxylase antibodies have been found in the sera of patients with IDDM and immunotherapies have been used in some patients with IDDM, yet the manner in which the dysfunctional immunosystem acts on beta cells and causes damage to them remains to be clarified. Recently, possible involvement of the abnormal production of IL-6 in autoimmune symptoms was suggested in patients with cardiac myxomas, Castleman's disease and rheumatoid arthritis. However reports of IL-6 abnormal production in patients with IDDM are rare. In the present study, we examined whether or not an abnormal expression of IL-6 mRNA was present in mononuclear cells (PBMNCs) of the peripheral blood of patients with IDDM. We devised a highly sensitive, specific and semiquantitative protocol, ie, reverse transcription and polymerase chain reaction (RT-PCR). We have used such an assay to measure the relative expression levels of IL-6 mRNA in PBMNCs from 12 early IDDM patients (duration < 6 mon, 8.20 +/- 3.85 yr), 29 newly-diagnosed NIDDM patients (54.85 +/- 9.12 yr), 23 normal children (8.20 +/- 3.26 yr) and 12 normal adults (31.92 +/- 11.22 yr). In this assay significantly high expression levels of IL-6 mRNA were found in PBMNCs from patients with IDDM (P < 0.05). The relative levels were 0.91 +/- 0.19; 0.10 +/- 0.06; 0.43 +/- 0.08; 0.10 +/- 0.07, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Study on the relationship between two second-messenger pathways on the regulation of proliferation and differentiation in MGc 80-3 cells].

By using an inducer of differentiation (HMBA) and blockers of signal pathways, the relationship between two second-messenger pathways (DG-PKC, cAMP-PKA) in inducer-mediated MGc80-3 cell differentiation was studied. Cells were treated with HMBA for 24 h, levels of DG decreased by 64.7%, activity of PKC decreased by 28.7%, while levels of cAMP and rate of it's protein binding increased by 62% and 32.6% respectively (after treated for 48 h, the result was more remarkable). PKA-R II distributed in nuclei. H7 (PKC inhibitor) was used to substitute for HMBA to block the DG-PKC pathway. After treatment for 24 h, the levels of DG and activity of PCK both decreased, while the levels of cAMP increased 1.04 times. On the contrary, PKA inhibitor was added while HMBA was used to induce cell differentiation, cAMP-PKA pathway was blocked, levels of cAMP and rate of it's protein binding decreased. But levels of DG and activity of PKC both increased to the levels of control cells. At this time, PKA-R II distributed only in cytoplasm. These results suggest that harmonious relations of the positive and negative regulation of cAMP-PKA and DG-PKC systems in cells during the proliferation and differentiation of cells. It also showed that positive regulation of PI system may play a leading role in MGc80-3 cells. It let to normal regulation of two signal pathway out of control to remain malignant phenotype of these cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Observing the 1H NMR signal of the myoglobin Val-E11 in myocardium: an index of cellular oxygenation.

The 1H NMR signal from oxymyoglobin, a low-concentration diamagnetic protein, is visible in myocardial tissue. The methyl group of the Val-E11 resonates in a clear spectral region at -2.76 ppm and responds to dynamic changes in cellular oxygenation. With CO, the signal shifts to -2.4 ppm. The Val-E11 peak assignment and its response to oxygen and CO agree perfectly with previous myoglobin solution studies. Intracellular oxygen level can now be determined in vivo with the signal intensity ratio of oxymyoglobin/deoxymyoglobin, reflected by the Val-E11 and His-F8 peaks in the 1H NMR spectra. Moreover, protein structure-function relationship in vivo can now be probed.

Adenosine Triphosphate↗
PubMed1992

Detection of antigens associated with lung carcinoma in sera by monoclonal antibodies WLA-2C4 and CL-3.

The levels of tumor-associated antigens (TAAS) corresponded to monoclonal antibodies WLA-2C4 and CL-3 in sera of 57 lung cancer patients, 100 healthy adults and 50 non-tumor disease patients were assayed with SABC-ELISA of immunobinding inhibition test. The threshold values of WLA-2C4 and CL-3 (RBI) were 12% and 36%, respectively. The positive results of lung carcinomas with at least one of the two TAAS were as follows: squamous cell carcinoma 89%; adenocarcinoma 83%; small cell carcinoma 67% and their mean positive rate was 79%. Whereas the positive rate in healthy adults and non-tumor disease patients was only 6%. These results indicate that using monoclonal antibodies WLA-2C4 and CL-3 simultaneously may be helpful to the serological diagnosis of lung carcinoma.

Adenocarcinoma↗
PubMed1991

Changes in strains of mutans streptococci induced by treatment with chlorhexidine varnish.

Isolates of mutans streptococci were obtained from the dental plaque of ten subjects before and after the subjects had been free of detectable mutans streptococci for a mean period of 14.6 weeks (range, from two to 36 weeks). The mutans streptococci had been rendered undetectable by chlorhexidine varnish treatment. Examination of the restriction endonuclease analysis (REA) patterns of the isolates revealed that all ten subjects had one strain (REA type) after re-appearance of the mutans streptococci that was identical to one that had been present before the varnish treatment. In six of the ten subjects, only one strain was detected both before and after treatment. Each of the other four subjects appeared to gain a new strain after treatment; one of the four appeared to lose one strain, and another, four strains. The ability of strains to persist after the period of undetectability seemed unrelated to their resistance to chlorhexidine or to their ability to exhibit insoluble glucan-mediated adhesion. In the subjects harboring multiple REA types, one-seventh of the tooth surfaces sampled harbored two strains simultaneously, suggesting an inability of either strain to exclude the other aggressively. Overall, the study indicated that every subject receiving chlorhexidine varnish therapy had a primary strain of mutans streptococcus that re-emerged after treatment. In contrast, secondary strains were highly susceptible to being lost or gained.

Adolescent↗
PubMed1991

[The study on ultrastructure of gap junction of rat atrial myocytes in primary culture].

We have studied the ultrastructure of gap junction of rat atrial myocytes of primary culture in situ embedded by ultramicrotomy. We observed a kind of gap junction-associated vesicles (GJAV), a kind of cluster of particles which are surrounded by plasma membrane, and a concatenate GJAV complexes (CGJAVC) in some big clusters. We found that both of GJAV and CGJAVC are very near the plasma membrane at the intercellular space, and at the same time they are usually adjacent the assembled GJ. So we infered that they are the pre-body or midproduct of the assembled GJ probably. This article analysed these observes and probed into the process about how to assemble the gap junction.

Animals↗
PubMed1991

Distribution and excretion of 3H-sterigmatocystin in rats.

In order to investigate the distribution and excretion of sterigmatocystin, a carcinogenic mycotoxin, radioactively labelled compound was studied in rats. The highest concentration of radioactivity in serum appeared 3 h after administration of 0.5 microCi/g bw. The half-lives of distribution and excretion were 0.51 h and 43.9 h, respectively. The radioactivity was concentrated mainly in liver, stomach, kidney, duodenum and lung and to a lesser extent in fat, muscle, testis, rectum and bone. By 48 h, 56.4% had been excreted in faeces and 20.1% in urine. Biliary excretion may be the major route of excretion of sterigmatocystin.

Animals↗
PubMed1991

[Significance of assaying serum bone GLA protein level in patients with hyperthyroidism].

The serum BGP level was assayed in patients with hyperthyroidism (untreated and remittent cases). The mean serum BGP concentration was 8.7 +/- 2.5 ng/ml in 54 patients with untreated hyperthyroidism, which was significantly higher than normal range (4.8 +/- 1.3 ng/ml P less than 0.01). Serum BGP had a significant positive correlation with the concentration of T3 and T4, while serum AKP had no correlation with circulating thyroid hormone levels. In the patients with hyperthyroidism, serum T3 and T4 decreased significantly after the first month of methimazole treatment, and fluctuated within the normal range since then. Serum BGP did not show significant change during the first six months of treatment, although they were eventually reduced significantly at the end of six months. These results suggest that serum BGP measurement is a valuable marker of bone metabolism alteration during hyperthyroidism.

Adult↗
PubMed1990

[The effect of db-cAMP on the gene expression of calmodulin and cytoskeleton in the transformed cells].

We have demonstrated that the distribution of microtubules (MT), microfilaments (MF) and fibronectin (FN) were diminished, while the gene expression of the calmodulin and c-fos enhanced in the transformed C3 H10 T1/2 cells. After treatment with 1 mM db-cAMP for 1 hr. and 2 hrs., there was an early and rapidly reduced in gene expression of calmodulin and c-fos respectively. After db-cAMP treatment for 4-5 days, the number of Capping cells of ConA binding decreased significantly and the cell surface microvilli decreased also. The growth of treated cells was inhibited markedly. By using 4F1 cDNA probe, which is preferentially expressed in G1 phase, we have found that the db-cAMP treated cells were accumulated at G1 phase. Of particular interest is the fact that the distribution of microtubules, microfilaments and fibronectin were recovered after treatment with 1 mM db-cAMP for 6 days. It is suggested that the inhibition of proliferation, alteration of phenotype and recovery of cytoskeleton in transformed cells after treatment with db-cAMP are related to the inhibition of gene expression of calmodulin.

Animals↗
PubMed1990

[Studies on the changes in calcium fluxes in ts-RSV LA 90 cells transformation].

To study the role of Ca2+ fluxes and [Ca2+]i in cell transformation by the v-src gene, ts-RSV LA 90 cells was used in this experiment. Ca2+ fluxes across the plasma membrane was measured with radioisotopes. The relative [Ca2+]i in LA 90 cells loaded Indo-1AM was measured by computer-based Optical Multichannel Analyzer connected with fluorescence microscopy. It was observed that changes in rate of Ca2+ fluxes across the plasma membrane are one of the earliest detectable changes of LA 90 cells transformation. Rates of Ca2+ fluxes in transformed LA 90 cells (40 degrees C) is higher than that in normal LA 90 cells (33 degrees C) and rates of Ca2+ fluxes increased in 25 minutes when LA 90 cells shifted from nonpermissive (40 degrees C) to permissive (33 degrees C) temperature. TMB-8 inhibited increases in rate of Ca2+ efflux induced by pp 60 v-src, and increase in rate of Ca2+ efflux in normal LA 90 cells was stimulated by calf serum. The rate of Ca2+ efflux was related to the changes in temperature. The increase in rate of Ca2+ influx induced by pp 60 v-src could be blocked by verapamil. The rate of Ca2+ influx was not affected by the changes in temperature. The increase in relative [Ca2+]i induced by pp 60 v-src is one of the early events in the transformation process. The level of [Ca2+]i in transformed LA 90 cells was about 2-3 times as much as that in normal LA 90 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[The effect of depolymerization of cytoplasmic microtubules on initiation of DNA synthesis by growth factors in cells].

PPP (platelet-poor plasma) alone can not stimulate DNA synthesis in Go C3H/10T1/2 cells.50 ng/ml of EGF promoted partial Go cells to enter S phase. However, there was an apparent synergic effect of simultaneous treatment with 50 ng/ml EGF and 5%PPP, their synergic effect to stimulate DNA synthesis in Go cells was the same as 10% calf serum. Taxol can resist the depolymerization of microtubules. After treatment with taxol (10 mumol/L), the progression from Go to S phase in C 3 H 10 T 1/2 cells was inhibited. This inhibition was especially exhibited at early stage of transition from Go to S phase. The result indicated that Go cells can not enter S phase without the depolymerization of microtubules. It showed that DNA synthesis was stimulated by the simultaneous treatment with colcemid (0.1 microgram/ml) and growth factors (50 ng/ml EGF + 5% PPP or 10% Calf serum). But without the stimulation of growth factors, the unique effect of depolymerization of microtubules can not stimulate DNA synthesis. The results present evidence indicating that the depolymerization of microtubules has the potency to elevate DNA synthesis in Go cells stimulated by growth factors. This potency was also appeared at early stage of progression from Go to S phase. We suggest that the depolymerization of cytoplasmic microtubules and synergic effect of growth factors are involved in account for the transition from Go to S phase in C 3 H 10 T 1/2 cells.

Alkaloids↗
PubMed1990

[Effects of superoxide dismutase on ischemic reperfusion injury in isolated working heart and cultured myocardial cells of rats].

An isolated working rat heart underwent 40 min of normothermic ceasing perfusion and 25 min of reperfusion. Superoxide dismutase (SOD) or/and mannitol were added to the perfusate 15 min before ceasing perfusion and 15 min after reperfusion. The results indicate that SOD (37,000 IU/L) improved significantly the contractile function of heart and increased the aortic output and coronary flow. Mannitol 0.02 mol/L provided additional benefit. The rat myocardial cells were cultured in the medium for 3 h with hypoxia followed by 2 h of reoxygenation. The content of lactic dehydrogenase (LDH) in the medium was increased and the degree of fluorescence polarization of myocardial cell membrane was raised. SOD was effective in preventing LDH release and decreasing the degree of fluorescence polarization. These results clearly demonstrate that ischemic reperfusion are capable of causing significant myocardial injury, which can be reduced or prevented by administration of oxygen free radical scavenger SOD.

Animals↗
PubMed1990

[Effects of nicardipine and chlorpromazine on proliferation and intracellular calmodulin in cultured aortic smooth muscle cells].

Effects of Ca2+ and calcium antagonists nicardipine (Nic) and chlorpromazine (CPZ) on the proliferation, DNA synthesis and intracellular calmodulin (CaM) levels in cultured rabbit aortic smooth muscle cells were investigated. Maximal response of cell to Ca2+ stimulation occurred in the normal medium with CaCl2 1.4 mmol/L, whereas CaCl2 0.02-0.6 mmol/L, Nic (2.5-40.0 mumol/L) and CPZ (5.0-20.0 mumol/L) inhibited the cell proliferation in a concentration-dependent manner. The additive effects of Nic and CPZ were observed. There was a transient surge of intracellular soluble CaM level at 9h in late G1 phase of the cell cycle just before the initiation of DNA synthesis. Not only the initiation of DNA synthesis but also the CaM surge were prevented by adding Nic or CPZ (20-40 mumol/L) to media. These results suggest that an appropriate extracellular Ca2+ concentration was required for aortic smooth muscle cells to grow normally. Since calcium antagonists influenced the intracellular Ca2+ pool by blockade of calcium channel and they inhibited the CaM function directly by anticalmodulin activity or indirectly through altered intracellular Ca2+ metabolism, intracellular Ca2+ and CaM levels may be involved in the effects of Nic and CPZ on the proliferation and DNA synthesis.

Animals↗
PubMed1990

The stimulatory effect of heavy metal cations on proliferation of aortic smooth muscle cells.

Heavy metal cations Cd2+, Pb2+, and Hg2+ were added to substitute for Ca2+ in culture media to study their effect on the relationship between CaM and the proliferation of cultured rabbit aortic smooth muscle cells (ASMC). It was found that all the heavy metal cations studied stimulated the proliferation of ASMC in varying degrees, increased the CaM content in cells at late G1 stage and decreased the activity of cAMP PDE. These results suggest that the adverse effect of heavy metals may be related to the pathogenesis of atherosclerosis and hypertensive disease.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

Surgical treatment of congenital choledochal cyst.

20 cases of congenital choledochal cyst were operated by modified Lilly's method from 1980 to November 1985 in our Hospital. There were 4 males and 16 females. Their ages ranged from 50 days to 15 years with a mean of 5.1 years. All patients had preoperative ultrasonographic examination, barium meal radiography of the gastrointestinal tract or percutaneous transhepatic cholangiography. All had choledochal cystectomy with retention of the outer layer of the posterior wall of the cyst. We modified Lilly's method by injecting normal saline between the outer and inner layer of the choledochal cyst so that the outer layer could be isolated. Reconstruction of the biliary tract was then performed. 2 patients had choledochoduodenostomy and 18 patients had hepaticojejunostomy (1 end to end and 17 end to side). 19 patients had also had cholecystectomy. The post-operative course of the operation was found to be smooth and safe. Patients were followed up for a period from 6 months to 7 years. 3 patients had cirrhosis of liver, 2 of whom died within 8 months. The mortality rate in our series was 10%. The operative treatment and the problems of biliary reconstruction are discussed.

Adolescent↗
PubMed1989

[Distribution and lateral mobility of concanavalin A receptors in the course of cell cycle of human gastric cancer cells].

The distribution and lateral mobility of Con A receptors in the course of the cell cycle has been studied on human gastric low-differentiated mucous adenocarcinoma cells (MGC 80-3). Synchronized MGC 80-3 cells in monolayer were labeled with F-ConA in the different phases of cell cycle. The discontinuous pattern of surface labelling was present during G1, S and G2, while there were marked differences among them. The cells in mitosis displayed uniform distribution of Con A receptors complex with strong fluorescence. The fluorescence photobleaching recovery method has been used to determine the lateral mobilities of Con A receptors complex. There was marked difference among various phases for mobility pattern and diffusion coefficient. The pattern of mobility of Con A receptor complex was appeared diffusion mobility in M and G1 phases, while flow pattern occurred in S and G2 phases. The diffusion coefficient (D) G1 greater than M, the rate of flow S greater than G2, but mobile fraction in G2 phase is higher than other phases. These results showed that dynamic properties of Con A receptor are apparently different which were regulated by the cell cycle.

Adenocarcinoma, Mucinous↗
PubMed1989

[X-linked recessively inherited peroneal muscular atrophy].

This article presents a pedigree of 80 members of which there are 13 patients (13 males) with peroneal muscular atrophy. The analysis of this pedigree shows that an affected male married to a normal female will have normal son(s) and carrier-daughter(s). The normal son(s) will have normal offspring, but half the sons of the carrier-daughter(s) will be affected. The pathogenic genes of affected males are transmitted to their daughters, but not to their sons. So this inheritance is of X-linked recessive type. This is the first report of X-linked recessively inherited peroneal muscular atrophy in china.

Adolescent↗