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D Cao

Publications and source records attributed to D Cao.

71 records · Page 4Linked to original sources
PubMed1997

Mechanisms for the coordination of intercellular calcium signaling in insulin-secreting cells.

Insulin-mediated increases in cytosolic calcium are synchronized among the cells in a pancreatic islet, and result in pulsatile secretion of insulin. Pancreatic beta cells express the gap junction protein connexin43 and are functionally coupled, making gap junctional communication a likely mechanism for the synchronization of calcium transients among islet cells. To define the mechanism by which pancreatic islet cells coordinate calcium responses, we studied mechanically-induced intercellular calcium waves in the communication-deficient rat insulinoma cell line RINm5f, and in RINm5f cells transfected with the gap junction protein connexin43. Both RINm5f and RINm5f cells transfected with connexin43 propagated calcium waves that required release of calcium from intracellular stores, did not involve gap junctional communication, and appeared to be mediated by autocrine activity of secreted ATP acting on P2U purinergic receptors. Connexin43 transfectants also propagated calcium waves that required gap junctional communication and influx of extracellular calcium through voltage-gated calcium channels. Gap junction-dependent intercellular calcium waves were inhibited by preventing plasma membrane depolarization. These studies demonstrate two distinct pathways by which insulin-secreting cells can coordinate cytosolic calcium rises, and show that it is by ionic traffic that gap junctions synchronize calcium-dependent events in these cells.

Animals↗
PubMed1997

[A pathological study of in situ thrombosis of small pulmonary arteries and arterioles in autopsy cases of chronic cor pulmonale].

OBJECTIVE: To study the incidence of thrombosis of small pulmonary arteries and arterioles during the exacerbation stage of chronic cor pulmonale. METHODS: 49 autopsy cases died from the exacerbation of chronic cor pulmonale were chosen as the study group, while other 103 autopsy cases without chronic cor pulmonale and disseminated intravascular coagulation (DIC) as control group. Morphologic and morphometric studies were taken on lung tissues and other organs with focus on the thrombi in small pulmonary arteries and arterioles. RESULTS: 44 cases of the study group had multiple thrombi in small pulmonary arteries and arterioles, the incidence is 89.8%, and in 9 of them, thrombi in proximal pulmonary arteries co-existed, the incidence is 18.4%, 80% of the thrombi existed in pulmonary arteriole. In control group, only 3 cases had thrombi in small pulmonary arteries and arteriole, the incidence is 2.9%. All thrombi adhered to endangium, implying that they were in situ thrombi. No intravascular thrombosis were found in other organs. chi(2) test showed that the incidence of thrombosis and the number of thrombi in small pulmonary arteries and arteriole in cases with chronic cor pulmonale were significantly higher than that of the control group (P < 0.01). CONCLUSIONS: Multiple in situ thrombosis in small pulmonary arteries and arterioles is a prominent and common pathological change during the exacerbation stage of chronic cor pulmonale. The study suggests a new diagnostic and therapeutic concept and provides a morphological and theoretical basis for the clinical application of anticoagulants or even the thrombolytic agents for the cases of chronic cor pulmonale in the exacerbation stage.

Aged↗
PubMed1995

Tissue-specific expression of two aldose reductase-like genes in mice: abundant expression of mouse vas deferens protein and fibroblast growth factor-regulated protein in the adrenal gland.

Aldose reductase (AR), the first enzyme in the polyol pathway, has been implicated in the pathogenesis of diabetic complications, although its physiological role is unclear. In mice, besides AR, two AR-like proteins, mouse vas deferens protein (MVDP) and fibroblast growth factor-regulated protein (FR-1), have been reported recently. Tissue-specific expression of these two genes was examined using the RNase protection assay method. Contrary to previous reports, MVDP was detected in a variety of tissues besides the vas deferens. High levels of MVDP mRNA were found in the adrenal glands, and low levels of expression were detected in eye, intestine, seminal vesicle, kidney, liver, testis and lung. The major gene expression pattern for FR-1 was slightly different from that of MVDP, with the highest levels of mRNA detected in testis, heart, adrenal gland, and ovary; less was found in the lung and it was barely detectable in eye, intestine, liver and seminal vesicle tissue. Mouse embryos, as early as 10.5 days post coitum, expressed both genes, although the levels of expression were different. Human AR mRNA was found in human vas deferens, although not at the high level found in mice. The localization of both MVDP and FR-1 transcripts in the adrenal cortex by in situ hybridization led to the speculation that these two AR-like proteins could be related to hormone production.

Adrenal Glands↗
PubMed1995

Human urokinase-type plasminogen activator primes neutrophils for superoxide anion release. Possible roles of complement receptor type 3 and calcium.

Urokinase-type plasminogen activator (uPA), which binds to cells via a specific receptor (uPAR), participates in pericellular proteolysis during leukocyte migration. Previous studies have indicated that uPAR is physically associated with CR3 (CD11b/CD18). To test the functional interactions of CR3 and uPAR, we have examined the ability of uPA to elicit changes in cytosolic calcium levels of normal neutrophils, neutrophils from a leukocyte adhesion deficiency (LAD) patient, and 3T3 transfectants expressing CR3, uPAR, or both. We found that calcium levels of neutrophils increased from 106 +/- 6 nM in untreated cells to 199 +/- 25 nM in the presence of uPA. In contrast, no significant change in calcium was observed when neutrophils from an leukocyte adhesion deficiency patient were examined. The uPA-dependent calcium rise was inhibited by mAb directed against either CR3 or uPAR and required intact uPA. To substantiate further these findings, we prepared transfectants expressing genes encoding uPAR, CR3, and both receptors; only cells expressing both receptors experienced a rise in intracellular calcium. Although uPA's calcium signal is insufficient to trigger superoxide production, FMLP dose-dependent superoxide production was greatly enhanced by incubating neutrophils with intact, but not fragmented, uPA. Flow cytometry experiments utilizing an FMLP analogue exclude the possibilities that urokinase binds to the FMLP receptor or up-regulates its expression. We suggest that calcium is a second messenger of uPA, that this message is mediated in a CR3-dependent fashion, and that this signal primes neutrophils for superoxide production.

3T3 Cells↗
PubMed1995

[Study on Bian Que's tomb and temple].

The historical archives and records and the existed Bian Que's tombs and temples in over a dozen of locations, including Hebei, Shandong, Henan, Shanxi, have aroused controversies as to which is the authentic one. So far, no conclusion can be drawn. By combining the burial and offering customs and rituals at the end of Spring-Autumn period, analyses are made on Bian Que's tombs, temples, former residence, Bian Que Village, Bian Que town, historical remains of Prince Guo and legends on location of Bian Que's activity for making immortal pills etc., it is claimed by the authors that, besides a few places related to Bian Que's life, all the others are tombs and temples built by local people where Bian Que's visited for his memory, and his merits, reflecting the historical facts about Bian Que's activities. All these historical and cultural remains are precious evidences for the historic appraisal of Bian Que by modern scholars.

China↗
PubMed1995

[Study of toxicity of iodophor,glutaradehyde and chlorhexidine to L929 Cells.].

We comparatively studied the toxicity of iodophor,glutaradehyde and chlorhexidine in different concentration and time.The result shows that the toxicity of iodophor to L929 cells is the lowest in all kinds of drug concentration and action time is much lower than that of glutaradehyde and chlorhexidine(P<0.05) with prolonging time.It indicates that iodophor can be used to oral diseases therapy with lower concentration.

English Abstract↗
PubMed1995

[A clinicopathological study of cor pulmonale with coronary heart disease].

The necropsy findings of 18 patients with cor pulmonale and coronary heart disease (CHD) were compared with those of a control group of 30 patients with cor pulmonale alone. The results showed that there was no significant statistical difference between the two groups on average heart weight and average left and right ventricular thickness (P > 0.05). The results suggest that at the end stage of cor pulmonale left ventricule may be involved whether there are complicating left ventricular disease or not. In this study, cor pulmonale and CHD were both accurately diagnosed in 33.3%, CHD failed to be diagnosed in 38.9% and cor pulmonale failed to be diagnosed in 27.8% of the patients. Single diagnostic factor analysis for cor pulmonale with CHD indicated that age, history of hypertension, history of angina pectoris, history of MI, accentuation A2, presence of bundle branch block, abnormal Q wave and left axis or normal deviation, Cheng Xiansheng diagostic criteria and Selvester MI screening criteria are of significance (P < 0.05). Multiple factor logistic regression analysis indicated that independent prognostic factors including history of angina pectoris, Selvester MI screening criteria and Cheng Xiansheng diagnostic criteria are of help for diagnosis (P < 0.03-0.000). The above-mentioned diagnostic methods are, however, not so specific. At present the best method for diagnosis of CHD is coronary arteriography.

Adult↗
PubMed1995

[Application of T-subgroup cells assay in the immunology of oral-maxillofacial cancer].

We report on T-subgroup cells in 70 cases of oral-maxillofacial cancer determined by T-monoclone antibody-OKT system. The results are as follows: CD3, CD4/CD8 value of cancer patients was decreased significantly, compared with that of health or oral benign tumor patients. CD8 was significantly increased (P < 0.001); however, CD8 was decreased and CD4/CD8 ratio was increased after operation. 20 cases underwent the dynamic testing, determined in 1 week, 1 and 3 month. The results are as follows: CD3, CD4, CD4/CD8 values were increased gradually and CD8 was decreased gradually in 17 cases of curative patients, but CD4, CD4/CD8, values were decreased and CD8 was increased significantly in 3 cases of metastased patients. Our conclusion is that determination of T-subgroup cells is of reference value for monitoring and treating cancer patients.

Adenocarcinoma↗
PubMed1993

Simultaneous calcium-dependent delivery of neutrophil lactoferrin and reactive oxygen metabolites to erythrocyte targets: evidence supporting granule-dependent triggering of superoxide deposition.

Optical microscopic techniques have been utilized to study the deposition of lactoferrin, a specific granule marker, and superoxide anions into target erythrocytes during antibody-dependent phagocytosis. Previous studies from this laboratory have shown that the entry of superoxide anions into erythrocytes can be sensitively monitored with Soret band transmitted light microscopy. When neutrophils were incubated with BAPTA/AM, an intracellular Ca2+ chelator, they phagocytosed IgG-opsonized sheep red blood cells (SRBC) but did not affect the microscopically detected absorption of their Soret band. When these same erythrocytes were observed after the infusion of 20 microM ionomycin, a Ca2+ ionophore, 58% of the cell-bound SRBC targets were destroyed immediately. However, neutrophils from chronic granulomatous disease (CGD) patients were unable to affect the Soret absorption of erythrocyte targets under any conditions. These results suggest that a Ca2+ signal can participate in triggering superoxide deposition in targets. Since Ca2+ signals are known to participate in the exocytic release of granules, we tested the hypothesis that specific lactoferrin-bearing granules are delivered to targets in parallel with superoxide anions. Lactoferrin delivery to phagosomes was monitored using resonance energy transfer (r.e.t.) microscopy. SRBCs were opsonized with both unconjugated and rhodamine B isothiocyanate (RBITC)-conjugated rabbit anti-SRBC IgG. After incubation with adherent neutrophils, the samples were washed, fixed with 3.7% paraformaldehyde, then labeled with fluorescein isothiocyanate (FITC)-conjugated antilactoferrin IgG. Energy transfer between FITC and RBITC was imaged microscopically and quantitated by photon counting. Significant levels of r.e.t. between antilactoferrin and anti-SRBC labels were observed after phagocytosis, but not in the absence of acceptor fluorochromes. To control for r.e.t. specificity, neutrophil membranes were labeled with FITC-conjugated, anti-HLA IgG after internalization of rhodamine B-tagged SRBCs (RSRBCs). Although r.e.t. between lactoferrin and RSRBCs labels was observed, no r.e.t. between HLA and RSRBC labels could be found. Further studies showed that treatment of neutrophils with BAPTA inhibited r.e.t. between anti-lactoferrin and RSRBCs. However, addition of ionomycin relieved this inhibition of energy transfer. These experiments show that both lactoferrin and superoxide delivery to targets are regulated in parallel by a Ca(2+)-dependent pathway. Furthermore, by combining Soret microscopy with r.e.t. microscopy, we have shown that superoxide anions and lactoferrin are delivered to the same phagosomes. We speculate that the NADPH oxidase, which produces superoxide anions, is assembled on specific granule membranes, thus accounting for their parallel Ca(2+)-dependence, activation, and delivery.

Calcium↗
PubMed1993

Deposition of reactive oxygen metabolites onto and within living tumor cells during neutrophil-mediated antibody-dependent cellular cytotoxicity.

In this study we test the hypothesis that reactive oxygen metabolites are delivered from neutrophils to simultaneously both the cell surface and cytosol of opsonized YAC erythroleukemic target cells. Using 5' (or 6') carboxyl-2',7'-dichlorodihydrofluorescein (H2-CDCF) diacetate as starting material, we synthesized its succinimidyl ester derivative. H2-CDCF-conjugated IgG prepared from the succinimidyl ester derivative was used to opsonize targets. In vitro studies have shown that H2-CDCF becomes fluorescent upon exposure to reactive oxygen metabolites, including hydrogen peroxide. Using video intensified epifluorescence microscopy, we observed that reactive oxygen metabolites are deposited on tumor cell membranes during neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC). This deposition process is catalase sensitive. The role of reactive oxygen metabolites produced by neutrophils in triggering the oxidation of H2-CDCF is further supported by the observation that neutrophils from chronic granulomatous disease (CGD) patients did not affect target fluorescence. YAC tumor cells were also labeled with dihydrorhodamine 123 or dihydrotetramethylrosamine. The oxidized forms of these reagents were found within the cytoplasm of YAC cells. During ADCC normal neutrophils, but not neutrophils obtained from CGD patients, triggered the oxidation of dihydrorhodamine 123 and dihydrotetramethylrosamine within tumor cells. Using two-color automated epifluorescence microscopy, we could not detect temporal intermediates with fluorescence in only one compartment, i.e., either solely on the plasma membrane or in the cytoplasm. These observations suggest that reactive oxygen metabolites cross target membranes (< 12 sec. These studies show that reactive oxygen metabolites are deposited both onto and into tumor cells during ADCC, wherein both compartments could become vulnerable to oxidant-mediated damage.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1993

[Studies on the chemical constituents of Lonicera macranthoides Hand. -Mazz].

Three bisdesmosidic triterpenoid saponins I-III, have been isolated from the flowers of Lonicera macranthoides Hand. -Mazz. By spectral (IR, MS, 1H-NMR and 13C-NMR) and chemical methods, I was proved to be identical with the known dipsacoside B, II and III were new compounds named macranthoidin A and macranthoidin B. Their structures were identified as follows: The prosapogenin of II, macranthoside A(IIb), was elucidated as 3-O-beta-D-glucopyranosyl-(1-3)-alpha-L-rhamnopyranosyl-(1-2)-alpha-L- arabinopyranosyl 3 beta, 23-dihydroxyl-olean-12-en-28-olic acid, II was established as 3-O-beta-D-glucopyranosyl-(1-3)-alpha-L-rhamnopyranosyl-(1-2)-alpha-L- arabinopyranosyl 3 beta,23-dihydroxyl-olean-12-en-28-O-beta-D-glucopyranosyl-(1-6)-beta-D- glucopyranoside. The prosapogenin of III, macranthoside B(IIIb), was elucidated as 3-O-beta-D-glucopyranosyl-(1-4)-beta-D-glucopyranosyl-(1-3)-alpha-L- rhamnopyranosyl-(1-2)-alpha-L-arabinopyranosyl 3 beta,23-dihydroxyl-olean-12-en-28-olic acid, III was established as 3-O-beta-D-glucopyranosyl-(1-4)-beta-D-glucopyranosyl-(1-3)-alpha-L- rhamnopyranosyl-(1-2)-alpha-L-arabinopyranosyl 3 beta,23-dihydroxyl-olean-12-en-28-O-beta-D-glucopyranosyl-(1-6)-beta-D- glucopyranoside. IIb and IIIb have not been reported in the literature.

Drugs, Chinese Herbal↗
PubMed1992

[Triterpene constituents from Euphorbia nematocypha Hand-Mazz].

Seven triterpenoids have been isolated from the roots of Euphorbia nematocypha Hand-Mazz. through chromatography on 20% AgNO3-silica gel. One of them was identified as a new compound named nematocyphol on the basis of spectral data (IR, EIMS, 1H-NMR and 13C-NMR). Its structure was deduced as IVa. Other compounds were identified as nepehinol acetate (I), germanicol acetate (II), euphol (III), tanaxastanol (Va), 24-methylenecycloartanol (VIa) and nepehinol (VIIa). These compounds were obtained for the first time from this plant.

Drugs, Chinese Herbal↗
PubMed1992

[Immune status of oral lichen planus and squamous cell cancer patients-T subgroup cells evaluation in PBL]

The levels of T-subgroup cells for 30 oral lichen planus(LP) and 25 cancers are reported.15 health are constracted.The results are as follows:Health OKT value T(3) 62.8+/-1.81,T(4) 44.4+/-7.34,T(8) 25.5+/-0.71,T(4)/T(8) 1.79+/-0.13;OLP OKT value:T(3) 53.2+/-1.92,T(4) 40.2+/-1.9, T(8)38.61+/-2.2, T(4)/T(8) 1.10+/-0.07,Cancer value 52.9+/-1.9,40.2+/-2.3,36.4+/-2.05,1.17+/-0.09. Both group of patients were compared with health.The level of OKT(3) OKT(4)/OKT(8) was decreased significantly(0.001),but OKT(8) qA increased significantly(0.001).This shows that T cell immune function is decreased in the oral LP and cancer patients.

Journal Article↗
PubMed1991

Influence of associated valvular lesions on long-term prognosis of mitral stenosis. A 20-year follow-up of 202 patients.

Other valvular lesions associated with pure MS were studied in 202 consecutive patients whose mean age was 43.4 +/- 12.7 years; 76.7% were females. MS was isolated in 63.4%, associated with aortic regurgitation (AR) in 27.7%, aortic stenosis in 1.0%, tricuspid stenosis (+aortic valve lesion) in 1.0%. In isolated MS, 42.4% were NYHA class III or IV, compared with 49.0% in MS + aortic valve lesion. One hundred and sixty-nine (85.4%) patients were operated on; 23.1% had mitral valve replacement, 76.9% had closed (31.4%) or open (45.6%) mitral commissurotomy; 7.1% had associated aortic valve replacement. There were perioperative complications in 20.4%, and the perioperative death rate was 4.1%. Two patients were reoperated in the postoperative course, and 28 patients after this period. The follow-up was 13.3 +/- 4.5 years. The survival rate was 77.7 +/- 4.6% (SE) for isolated MS, and 71.1 +/- 6.3% for MS associated with an aortic valve lesion (NS). The prognosis of MS is very good: the survival rate at 20 years follow-up is 75%. The association of aortic stenosis or tricuspid stenosis does not appear to alter this survival, but numbers are small. Important aortic regurgitation is a significant predictor of higher mortality in patients with MS.

Adolescent↗
PubMedDate not supplied

CD28nullCD4+ T cells--characterization of an effector memory T-cell population in patients with rheumatoid arthritis.

CD4+ T cells lacking the costimulatory molecule CD28 have been described both in elderly individuals and in chronic inflammatory disorders, one being rheumatoid arthritis (RA). We, in this study, provide a comprehensive characterization of cell surface markers on and function of such CD28nullCD4+ T cells, as well as correlations with clinical parameters. We conclude that of all surface markers associated with these cells, only CD57 and CD11b are expressed on the majority of them. This CD28null population occurred in one-third of patients with RA and was independent of clinical characteristics. The population was persistent and expanded in peripheral blood, but was excluded from the joint in most patients. Functionally, CD28nullCD4+ T cells were potent effector memory cells with regard to their proliferation and cytokine-secretion profiles. This capacity correlated with a hitherto unpublished surface phenotype, the cells being uniformly CCR7- and CD43high. Moreover, a new terminally differentiated CD45RA+CCR7- population of CD4+ T cells was identified. We would like to suggest that in the unbalanced immune system of patients with autoimmune disease and chronic infection an expanded CD28nullCD4+ T-cell population able to secrete high levels of cytokines is likely to contribute to disease manifestations.

Adult↗