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Biomedical subjects

Y Jiang

Publications and source records attributed to Y Jiang.

At least 649 records · Page 36Linked to original sources
PubMed1992

Inhibition of ongoing immunoglobulin production by eosinophil cationic protein.

The effect of eosinophil cationic protein (ECP) upon ongoing immunoglobulin (Ig) production and proliferation in human B cells was studied. ECP inhibited Ig production by the human lymphoblastoid cell lines, CBL and GM-1056, in a dose-dependent fashion. In contrast, proliferation was not affected. This ECP-induced inhibition of Ig production was specific, since inhibition was blocked by anti-ECP serum but not by control serum. Interleukin (IL)-4 did not affect Ig production by CBL or GM-1056 cells; however, IL-4 reversed ECP-induced inhibition of Ig production and this reverse was blocked by anti-IL-4 antibody but not by control antibody. In contrast, other cytokines, including IL-1 beta, IL-2, IL-3, IL-5, IL-6, interferon (IFN)-alpha, and IFN-gamma, failed to reverse inhibition. ECP also inhibited spontaneous Ig production (IgM, IgG1, IgG2, IgG3, IgG4, and IgA) by tonsillar large activated B cells without affecting proliferation. This inhibition was also blocked by anti-ECP serum but not by control serum and was reversed by IL-4 specifically. These results indicate that ECP may play an important role in B cell responses.

Antibody Formation↗
PubMed1992

Parathyroid hormone inhibits immunoglobulin production without affecting cell growth in human B cells.

The effect of parathyroid hormone (PTH) on immunoglobulin (Ig) production and proliferation in the human B-cell lines CBL, SKW, and CESS was studied. PTH inhibited Ig production from all the B-cell lines in a dose-dependent manner during 5 days of culture. As little as 0.1 ng/ml was inhibitory. PTH also inhibited Ig production from cell lines stimulated by vasoactive intestinal peptide (VIP), interleukin 2 (IL-2), and IL-6. This inhibition was not due to decreased cell growth since proliferation was not affected and cell viability was always greater than 98%. In contrast to PTH, inactivated PTH or triiodothyronine failed to affect Ig production. Inhibition by PTH was blocked by anti-PTH serum, but not by control serum. Of the various cytokines tested, IL-4 reduced the PTH-induced inhibition of Ig production, whereas other cytokines, including IL-1 beta, IL-3, IL-5, interferon alpha (IFN-alpha), IFN-gamma, and granulocyte-macrophage colony-stimulating factor (GM-CSF), failed to do so. The reducing effect of IL-4 was blocked by anti-IL-4 antibody but not by control antibody. Moreover, IFN-alpha and IFN-gamma, but not GM-CSF, overcame the reducing effect of IL-4. PTH also inhibited IgG, IgM, and IgA production by tonsillar B cells stimulated with Staphylococcus aureus Cowan strain I (SAC) and IL-6 without affecting proliferation. This inhibition was blocked by anti-IL-4 antibody but not by control antibody. These results indicate that, in addition to its regulatory effect on calcium metabolism, PTH also acts as an immunoregulatory factor, and that it interacts with the cytokine, IL-4.

Antibody Formation↗
PubMed1992

Screening and confirmation of drugs in urine: interference of hordenine with the immunoassays and thin layer chromatography methods.

Hordenine cross-reacted with various enzyme linked immunosorbent assay (ELISA) or radioimmunoassay (RIA) kits used for the screening of urine samples. Morphine-ELISA kit was most sensitive, whereas etorphine- and buprenorphine-ELISA kits were least sensitive to hordenine cross-reactivity. Hordenine also interfered with the thin layer chromatography of oxymorphone, hydromorphone and apomorphine. The major source of hordenine in humans is beer brewed from barley, whereas the major source of hordenine in horses is canary grass or barley. Therefore, the presence of hordenine in the urine of humans consuming beer or in the urine of horses consuming canary grass may give false positive values when the immunoassay and TLC methods are used for the screening of the urine sample. In order to distinguish hordenine from the opiate drugs, simple and sensitive gas chromatographic/mass spectrometric (GC/MS) and high performance liquid chromatographic (HPLC) methods have been developed in this study.

Alkaloids↗
PubMed1992

Regulated expression of monocyte chemoattractant protein-1 in normal human osteoblastic cells.

An influx of monocytes is observed in many different physiological and pathophysiological states, including bone remodeling and injury. These cells appear at early stages of bone formation and repair and persist throughout the later stages. In experiments described here, unstimulated normal human osteoblastic cells did not produce detectable levels of monocyte chemotactic activity. However, interleukin-1 (IL-1)-stimulated normal human osteoblastic cells produced a chemoattractant that is similar to monocyte chemoattractant protein-1 (MCP-1) at the levels of mRNA expression, protein production, and chemotactic activity. Northern blot analysis indicates that IL-1 elicits a dose-dependent increase in MCP-1 mRNA in normal human osteoblastic cells. Two proteins of M(r) 9,000 and M(r) 13,000 were specifically immunoprecipitated with MCP-1 antiserum from IL-1-stimulated normal human osteoblastic cells. Monocyte chemotactic activity from IL-1-treated cells was blocked by MCP-1 antiserum. These studies establish that normal human osteoblastic cells can be induced to produce monocyte chemoattractants and that this is accounted for by the induced expression of MCP-1.

Blood Platelets↗
PubMed1992

Influences of ginsenosides Rb1, Rb2, and Rb3 on electric and contractile activities of normal and damaged cultured myocardiocytes.

Free radical damage to the cultured myocardiocytes of Wistar rat was induced by adding xanthine 0.42 mmol.L-1 and xanthine oxidase 5.3 nmol.L-1 to the culture medium. 30 micrograms.ml-1 of Rb1, Rb2 or Rb3 extracted from the leaf and stem of Panax ginseng C A Meyer restored the action potentials (AP) of free radical damaged cells to normal, indicating their antioxidative action. On normal myocardial cells, Rb1, Rb2, Rb3 20 micrograms.ml-1 inhibited the AP and spontaneous contractility, (suggesting the Ca channel blockade action of panaxadiol saponins). The degrees of their inhibitory effects were found to be Rb1 > Rb2 > Rb3. Their effects against X-XO were basically the same.

Action Potentials↗
PubMed1992

Human B-cell growth-inhibitory activity of eosinophil cationic protein.

The effect of eosinophil cationic protein (ECP) upon proliferation of human B cell lines or purified B cells was studied. ECP inhibited proliferation of the human lymphoblastoid cell lines CBL and GM-1056 at doses of 0.1-5 ng/mL during 2-4 days of culture. The inhibitory effect of ECP was reversible and not due to toxic damage. Moreover, inhibition could be blocked by anti-ECP serum while the control serum failed to do so. Of various cytokines tested--including interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6; interferon (IFN)-alpha or IFN-gamma--IL-4 reduced the inhibition, while other cytokines failed to do so. The reduction of inhibition was specific to IL-4 since reduction by IL-4 was blocked by anti-IL-4 antibody but not by the control antibody. ECP also inhibited proliferation of tonsillar small resting B cells stimulated with anti-mu antibody plus low molecular weight B-cell growth factor (BCGF) or of large activated B cells. In contrast, ECP had no effect on proliferation of unstimulated small resting B cells. This inhibition was also reduced by IL-4 specifically. These results indicate that ECP may also act as a B-cell regulating factor.

B-Lymphocytes↗
PubMed1992

[Ca2+ channel blocking effect of panaxadiol saponins and panaxatriol saponins of cultured cardiac cells].

It was found that PDS and PTS decreased the action potential parameters of the cultured myocardiocytes in a dosage-dependent way. The effects of PDS 1000 micrograms/ml, PTS 200 micrograms/ml were in correspondence with the known Ca2+ channel blocker Mn2+ 0.05 micrograms/ml. Washing out, administration of epinephrine 10 micrograms/ml or Ca2+ 80 micrograms/ml were able to reverse the action potential from inhibition. The above results indicate that both PDS and PTS have Ca2+ channel blockade action.

Action Potentials↗
PubMed1992

[Salvia miltiorrhizae in the treatment of the viral myocarditis].

In Order to evaluate the effect of Salvia miltiorrhizae (SM) on the acute viral myocarditis (AVM), 60 children with AVM were studied. The patients were divided in random into two groups, group 1 treated with vit. C, ATP, CoA (n = 30), group II with SM plus vit. C, ATP, CoA (n = 30). The levels of plasma lipid peroxide (LPO), erythrocyte membrane microviscosity (EMMV), LDH, CPK, GOT and ECG in each patient were determined before and after one course of treatments respectively. The results revealed that before treatment the levels of plasma LPO and EMMV in both groups increased significantly compared with those of normal controls (n = 30, P < 0.01) respectively. There was a close correlation between LPO and EMMV (r = 0.6774, P < 0.01) and a close correlation between LPO and LDH (r = 0.5703, P < 0.01). After one course, the levels of plasma LPO and EMMV in both groups decreased significantly (compared with those before treatment, P < 0.01, respectively). But the LPO level and EMMV in group I were much higher than those in normal controls yet (P < 0.05, respectively). And LDH, GOT and ECG in nearly half of the patients in group I did not recover after one course while most patients in group II recovered. The results suggested that free radical plays an important role in the pathogenesis of AVM. SM as a good antioxidant, could protect myocardium from repairing membrane damage and clearing away free radical. This provided a new approach to treatment of viral myocarditis.

Child↗
PubMed1992

[The toxicity of herbicide Asulam].

We conducted a series of toxicity tests and short-term mutagenic assays of Asulam and 40% (W/V) sodium Asulam. It was found that the LD50 of Asulam with acute oral toxicity was 30000 mg/kg for mice, and the LD50 of sodium Asulam for mice and rats were equal (8250 mg/kg). The cumulative coefficient of sodium Asulam in Wistar rats was 9.42. None died from sodium Asulam absorbed via skin. Negative results were obtained in Ames test, Bacillus subtilis repair test and the micronucleus test. There was no significant difference between the control group and the treated groups in the chromosomal aberration rates of spermatogonia and primary spermatocytes of mice testis. The results indicated that Asulam should be regarded as a substance of low toxicity and low accumulation. No mutagenicity was observed in our experiment.

Animals↗
PubMed1992

Effects of copper and selenium on electric parameters of cultured myocardial cells damaged by xanthine-xanthine oxidase.

Addition of xanthine 0.42 mmol.L-1 and xanthine oxidase 5.3 nmol.L-1 (X-XO) to the culture medium increased the amplitude of ESR spectra of myocardial cells, demonstrating an increase in free radical contents; diminished the action potential parameters significantly and reduced the input impedances from 0.34 +/- 0.11 to 0.24 +/- 0.1 M omega, expressing a typical electrical appearance of membrane damage. Supplying Cu 62.5 ng.ml-1 and/or Se 173 ng.ml-1 to the medium brought all of the electric parameters and the free radical content of myocardial cells back to normal. The results indicate that both the two trace elements are able to scavenge free radicals, thus antagonizing X-XO, which induces damage to myocardial cells.

Action Potentials↗
PubMed1992

Surgical approach to segment I for malignant tumors of the liver.

Seven complete and 13 partial resections of segment I (caudate lobe) were performed for malignant tumors. In all except one instance, removal of segment I was combined with other types of hepatic resection for technical or carcinologic reasons. Six were iterative hepatic resections for recurrent hepatic metastases. In two, the future remaining left lobe was hypertrophied by right portal venous embolization preoperatively. Hepatectomies were performed with intermittent portal triad clamping (mean total duration of 63 minutes, range of 20 to 120 minutes) and after preparation for total vascular exclusion. Associated partial resection of the inferior vena cava was necessary in three instances. Mean duration of operation was 285 minutes (range of 60 to 540 minutes) and mean blood loss was 1,749 milliliters (range of 200 to 5,200 milliliters). There was no postoperative mortality and the morbidity rate was low. Surprisingly, we discovered retrospectively that free margins were small (less than 5 millimeters) in 83 percent of the patients. Regardless of limited free margins and six iterative hepatectomies, eight patients were free of disease with a mean follow-up examination period of 19.2 months. Technical problems were different for each patient and a patient by patient adaptation was necessary. Left, right and central approaches were used accordingly. If resection of segment I associated with a right or left hepatectomy can be currently considered as a standard hepatic resection, isolated complete resection of segment I remains a real technical challenge.

Adult↗
PubMed1991

Initial characterization of the carbohydrate structure of MCP-1.

MCP-1 is the principle monocyte chemoattractant produced by tumor cells in vitro. We previously identified different isoforms of MCP-1. Here we report that two predominant isoforms of MCP-1 (13 kD and 9 kD) can be distinguished by lectin binding. The results indicate that the disaccharide galactose-beta 1-3D-N-acetyl galactosamine is present on the 13 kD MCP-1 isoform but not the 9 kD isoform. Glycosylation of the 13 kD MCP-1 isoform does not appear to significantly change its antigenic properties and also does not affect its capacity to induce monocyte migration.

Carbohydrate Sequence↗
PubMed1991

Association of HLA antigens with Vogt-Koyanagi-Harada syndrome in a Han Chinese population.

Vogt-Koyanagi-Harada syndrome, or the uveomeningitis syndrome, is one of the most commonly identified types of endogenous uveitis diagnosed in China. Because its incidence is higher in Orientals than in whites, immunogenetic background [corrected] may be an important factor in its incidence. We performed HLA-A, -B, and -DR typing on 25 patients with Vogt-Koyanagi-Harada syndrome and on 65 healthy control subjects from the Han Chinese population. The results showed that HLA-DR4 and -Dw53 were closely associated with Vogt-Koyanagi-Harada syndrome (P less than .001 [relative risk = 16.0] and P less than .001 [relative risk = 34.2], respectively). This association is similar to that reported in patients with Vogt-Koyanagi-Harada syndrome in Japan, suggesting that DR4 and DRw53 may play important roles in the development of Vogt-Koyanagi-Harada syndrome in Oriental populations.

Adolescent↗
PubMed1991

NMR imaging study of the pharmacodynamics of polylysine-gadolinium-DTPA in the rabbit and the rat.

The pharmacodynamics of polylysine-(Gd-DTPA) (Schering, Berlin, Germany), a new blood pooling contrast agent for MRI, were studied in the rabbit and the rat. Polylysine-(Gd-DTPA) is a compound with high LD50. Due to its high molecular weight (50.000) and physico-chemical properties, it remains in the vascular system; during the first hour, the plasma level is three times higher than for Gd-DTPA. MRI was performed at 1.5 T using a SE sequence with TR/TE = 300/15 or 20 msec. Signal intensities of muscle, liver and kidney were measured before and after intravenous injection of the contrast agent (0.1 mmol/kg) during 8 hours in the rat (n = 3) and up to 2 wk in the rabbit (n = 3). A dose response study in three additional rabbits confirmed that the 0.1 mmol/kg dose was optimal. The pharmacodynamics results show that the effects of polylysine-(Gd-DTPA) are similar in both the rabbit and the rat. The liver signal is enhanced by about 60% immediately after injection in both species. This enhanced signal decays to half its maximal value in about one hour, which makes the contrast agent useful for clinical applications at a dose of 0.1 mmol/kg. In the kidney medulla and cortex the signals are enhanced by much larger factors (about 3 to 4); it takes at least one day for the kidney to clear the contrast agent in both species.

Animals↗