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B Zhang

Publications and source records attributed to B Zhang.

At least 595 records · Page 33Linked to original sources
PubMed1993

In vivo kinetics of oxidatively modified HDL.

The kinetics of oxidatively modified high-density lipoprotein (HDL) in vivo were investigated. 125I-labeled oxidized (Ox) HDL and 131I-labeled native (N) HDL were injected simultaneously into control and WHHL rabbits. The fractional catabolic rates of 125I-labeled Ox-HDL were significantly greater than those of 131I-labeled N-HDL in both control (2.52 +/- 0.36/day vs 0.94 +/- 0.02/day) and WHHL rabbits (4.07/day vs 1.32/day). Oxidized HDL was catabolized faster than native HDL and was taken up primarily by the liver, spleen, and kidney.

Animals↗
PubMed1993

Proliferation of SP- and 5HT-containing terminals in lamina II of rat spinal cord following dorsal rhizotomy: quantitative EM-immunocytochemical studies.

The density of substance P (SP) and serotonin (5HT) immunoreactivity in laminae I and II of rat spinal cord changes following dorsal rhizotomy in a manner consistent with sprouting by intrinsic SP and descending 5HT systems (Wang et al. J. Comp. Neurol. 304: 555, 1991). In this study we used quantitative EM-immunocytochemistry to examine whether the increase in substance P and serotonin immunoreactivity seen at the light microscopic level was related to increased numbers of SP- and 5HT-containing terminals in lamina II. Dorsal roots were sectioned and their ganglia removed from L1 to S2 unilaterally in 18 rats. After 3 (acute), 10 (subacute), or 60 (chronic) days, rats were perfused, and the L5 segments of the spinal cord were removed and prepared for electron microscopy. Lumbosacral deafferentation completely and permanently eliminated complex terminals in lamina II at L5 but the number of simple terminals increased by 46% compared to the control side. This result was similar to that shown previously in cat (Murray and Goldberger, J. Neurosci. 6: 3205, 1986) and suggested that intact intrinsic systems sprouted to form new terminals to compensate for the terminals lost by deafferentation. Quantitative electron microscopic immunocytochemistry demonstrated that the number of terminals containing SP in deafferented lamina II decreased by 58% at 3 days post-operatively and then increased by 10 days and recovered to normal levels by 60 days. The loss of SP terminals in the acute group is due to the loss of SP-containing dorsal root afferents, while the recovery in the chronic group suggests replacement of lost terminals by intrinsic SP systems. These results therefore indicate that SP-containing terminals show homotypic sprouting in response to complete dorsal root deafferentation. The number of 5HT-containing terminals in lamina II of spinal cord increased by 56% on the deafferented side in the chronic group. The increase in 5HT-containing terminals indicates that descending 5HT systems undergo heterotypic sprouting in response to dorsal rhizotomy.

Animals↗
PubMed1993

Regulation of interleukin-6 (IL-6) expression: evidence for a tissue-specific role of protein kinase C.

The regulation of IL-6 mRNA expression was studied in human blood monocytes and in the human epidermoid carcinoma cell line HEp-2. In human monocytes phorbol-12-myristate 13-acetate (PMA) did not induce IL-6 but it increased IL-1 beta and IL-8 mRNA levels. Furthermore, in monocytes, protein kinase C (PKC) activation by PMA even reduced IL-1-induced IL-6 mRNA, and IL-1-induced IL-6 synthesis was increased by the PKC inhibitor staurosporine. IL-6 synthesis in HEp-2 cells was induced by IL-1, PMA, and calcium ionophore A 23187 but not by dibutyryl-cAMP. PMA-, but not IL-1-induced IL-6 synthesis in HEp-2 cells was inhibited by staurosporine. PMA pretreatment of HEp-2 cells abolished PMA-induced IL-6 but the IL-1 effect was not reduced. These data indicate that IL-6 can be induced by a PKC-independent pathway in monocytes and HEp-2 cells. In monocytes PKC activation does not induce IL-6 and PMA interferes with the IL-1 effect. Transcription factors known to be involved with the regulation of IL-6 expression were studied by gel retardation assays. NF-IL-6 and AP-1 activity were constitutively expressed in monocytes and HEp-2 cells under conditions where IL-6 mRNA was not detectable and levels did not change in response to stimulation by IL-1 or PMA. In contrast, NF-kB was increased by both IL-1 and PMA, but only the effect of PMA, and not that of IL-1, was inhibited by staurosporine. In summary, these results show tissue-specific differences in the regulation of IL-6 expression. Induction of IL-6 in monocytes is PKC independent. In the epithelial cell line HEp-2 IL-6 is inducible by PKC as well as by a PKC-independent pathway.

Alkaloids↗
PubMed1993

Combined therapy with probucol and pravastatin in hypercholesterolaemia. One year follow-up study.

The effect of co-administration of low doses of pravastatin to hypercholesterolaemic patients already receiving long-term probucol treatment (mean 500-1,000 mg/day for 350 days) were investigated. Pravastatin 5 mg/day (Group 1; 12 m, 13 f; mean age 59.1 y) or 10 mg/day (Group 2; 8 m, 11 f; mean age 60.8 y) was administered, and blood was taken after 0, 3, 6, and 12 months. Both groups showed a significant reduction in serum total cholesterol (TC), phospholipid (PL), low density lipoprotein-cholesterol (LDL-C), LDL-triglyceride (TG), LDL-PL, apolipoprotein (apo) B, and apo E after the combined therapy. These levels were reduced more in Group 2 than in Group 1 subjects. In Group 2, significant falls in serum TG and apo CII were also observed. The changes in TC, PL, LDL-C, apo B, apo CII and apo E were dependent upon the dose of pravastatin, as assessed by two-way analysis of variance. Serum high density lipoprotein (HDL)3-C, apo AI and apo AII were slightly but significantly increased in both groups after 12 months of combined therapy, but the increase was not sufficient to reverse the probucol-induced lowering of the HDL level. We conclude that combined therapy resulted in a significant reduction in atherogenic lipoproteins and apolipoproteins, and an increasing dose of pravastatin (5 mg to 10 mg daily) made the lipid lowering effect more prominent. The reduction in serum HDL-C due to long-term probucol administration was not reversed by the addition of pravastatin.

Adult↗
PubMed1993

Apolipoprotein(a) phenotypes and serum lipoprotein(a) levels in maintenance hemodialysis patients with/without diabetes mellitus.

We studied the quantitative and qualitative characteristics of lipoprotein(a) [Lp(a)] as a function of apolipoprotein(a) [apo(a)] phenotypes in 152 patients (123 males, 29 females) undergoing maintenance hemodialysis (HD) with or without diabetes mellitus (DM), in 101 patients with diabetes mellitus without hemodialysis (58 males, 43 females), and in 421 normal controls (333 males, 88 females). Serum Lp(a) levels were significantly (P < 0.01) higher in patients than in controls (26.2 +/- 18.3 mg/dl in HD with DM, 26.4 +/- 22.0 mg/dl in HD without DM, 27.1 +/- 27.3 mg/dl in DM without HD, and 14.9 +/- 13.7 mg/dl in controls, respectively). Apo(a) phenotyping was performed by a sensitive, high resolution technique using SDS-agarose/gradient (3 to 6%) PAGE. In normal controls, the molecular weights of apo(a) isoforms were inversely correlated with plasma Lp(a) levels, and the same tendency was found in patients who were undergoing hemodialysis and/or who had diabetes mellitus. We assumed the differences in apo(a) phenotypes detectable with our method reflected consecutive differences in molecular weights of apo(a). The results of an analysis of covariance and a least square means comparison indicated that the regression lines between serum Lp(a) levels [log Lp(a)] and apo(a) phenotypes in patient groups were significantly (P < 0.01) elevated for every apo(a) phenotype, as compared to the regression line of the control group. Even after the low molecular weight apo(a) phenotypes (A1-A8) were omitted, the same tendency was observed. However, no differences were observed between the patient groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Isolation and characterization of two related Arabidopsis ocs-element bZIP binding proteins.

Ocs-elements are a group of related, bipartite promoter elements which have been exploited by two distinct groups of plant pathogens, Agrobacterium and certain viruses to express genes in plants. The genes for two Arabidopsis bZIP (basic region-leucine zipper) proteins that bind to ocs-elements have been isolated and characterized. The genes, called OBF4 and OBF5, were isolated by screening an Arabidopsis genomic library with degenerate oligonucleotides complementary to the DNA-binding domains of other plant ocs-element-binding proteins. The OBF4 and OBF5 proteins show 53% amino acid identity but low DNA homology. Southern blot analysis demonstrated that each of the OBF genes is a member of a small family. OBF4 is more similar to the tobacco TGA1a and Arabidopsis TGA1 proteins, while OBF5 is more similar to the maize OBF3.1, wheat HBP1b and Arabidopsis aHBP1b proteins. The DNA-binding properties of OBF4 and OBF5 were similar although OBF5 was able to bind simultaneously to both halves of the ocs-element more efficiently than OBF4. This difference in binding to the ocs-element between two closely related proteins from the same species is potentially significant since binding to both halves of the ocs-element is a pre-requisite for in vivo transcriptional activity.

Amino Acid Sequence↗
PubMed1993

A comparison of the early antithrombotic effects between low molecular weight heparin and heparin in small arteries following a severe trauma: an experimental study.

Twenty-seven rabbits divided into 4 groups (2 control groups) received saline, standard heparin (400 IU both as anti-F Xa and activated partial thromboplastin time per kg of body weight), or low molecular weight heparin (lmwh) (Fragmin 560 IU as anti-F Xa and 140 IU as APTT units per kg of body weight). The figures represent the total dose given over 3 hours. The central arteries of the rabbits' ears were prepared and positioned in clamps. Platelets labeled with 32P were injected. Arteriotomy/intimectomy was performed. After reestablishment of blood flow, arteriotomy bleeding times, platelet accumulation, patency, and weight of thrombotic materials were measured. The bleeding time in the Heparin Group was significantly prolonged compared with its control group. But the bleeding times between the LMWH Group and the control group were not significantly different. The patency rates were increased in both the Heparin Group (100%, p < 0.01) and the LMWH Group (73%, p = 0.078) compared with respective control groups (43-50%). The mean weights of thrombotic material in each artery were significantly lower in the Heparin Group and in the LMWH Group than in their control groups. The mean values of radioactivity in all groups increased up to 15 minutes after the vessels were reperfused. There were no statistical differences between the treated groups and control groups. It was concluded that standard heparin is a very powerful inhibitor of thrombosis during the most crucial hours after reperfusion of severely traumatized small arteries, without significant effects on primary platelet adhesion/aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Inhibition of cisplatin-mediated DNA damage in vitro by ribonucleotides.

Effects of ribonucleotides on cis-diamminedichloroplatinum(II) (cisplatin)-mediated DNA damage were studied by incubating pUC18 DNA with cisplatin in the presence of nucleotide, and by monitoring conformational change and sensitivity change to restriction enzyme HpaII of the DNA due to the platinum-DNA adduct formation. The cisplatin-mediated DNA damage was inhibited in a dose-dependent fashion by ATP or GTP, substantially at their physiological intracellular concentrations, and almost completely by 5 mM ATP or 2 mM GTP. The inhibitory effect of nucleotide on the platination of DNA was in the order of GTP > ATP >> CTP > UTP, and of nucleoside triphosphate > nucleoside diphosphate > nucleoside monophosphate. Nucleoside did not show any significant effect on platination of DNA. To elucidate the mechanism of the nucleotide effects on platination of DNA, interaction between ATP or GTP and cisplatin was analyzed by high-performance liquid chromatography. The results suggested that ATP inhibits cisplatin-mediated DNA damage both by forming a platinum-ATP adduct and by non-covalent ionic interaction with cisplatin, while GTP acts largely by forming platinum-GTP adducts.

Cisplatin↗
PubMed1993

In vivo kinetics of lipoprotein(a) in homozygous Watanabe heritable hyperlipidaemic rabbits.

In vivo kinetics of lipoprotein(a) [Lp(a)] were investigated in homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits (an animal model of familial hypercholesterolemia (FH)), and in normolipidemic Japanese White rabbits (controls). 125I-labelled Lp(a) and 131I-labelled LDL were simultaneously injected intravenously. Blood samples were then taken periodically. Kinetic parameters were calculated from the plasma radioactivity decay curves. The fractional catabolic rates (FCRs) of both Lp(a) and LDL (1.355 +/- 0.189 pools per day and 1.278 +/- 0.397 pools per day, respectively) in the WHHL rabbits were significantly (P < 0.005) smaller than those in the control rabbits (2.008 +/- 0.083 pools per day and 2.855 +/- 0.759 pools per day, respectively). In WHHL rabbits, the FCRs of Lp(a) and LDL were similar. However, in control rabbits, the FCR of Lp(a) was significantly (P < 0.01) smaller than that of LDL. In WHHL rabbit organs, the mean ratio of 125I-Lp(a): 131I-LDL, 48 h after injection, normalized to the corresponding isotope ratio in plasma, were 1.525, 1.020, 1.819 and 1.967, in liver, kidney, spleen and bile, respectively. These values were significantly higher than the corresponding values in control rabbits (0.590, 0.677, 0.862 and 0.766, respectively). Our data strongly suggest that Lp(a) clearance is not entirely dependent upon LDL receptors and may be mediated by some other mechanisms.

Animals↗
PubMed1993

An observation on flash evoked cortical potentials and Qigong meditation.

The purpose of this study was to investigate the functional state of the cerebral cortex during Qigong meditation with flash visual evoked potentials (F-VEPs) recorded from the occipital scalp in four groups of adults. The first group included 14 subjects who had exercised in Neiyang Gong for 0.5-5.5 years. The second group was composed of 12 subjects who had practiced Neiyang Gong for only 0.5-3 months. Eleven subjects who had never practiced Qigong before made up the third group and served as control. Eleven Qigong practitioners constituted the fourth group. It was found that F-VEP amplitudes were increased in the first group and decreased in the fourth group with the exception of one subject during Qigong meditation. No significant changes were found in the second group and controls. The results were discussed and it is shown that Qigong mediation may have either facilitative or inhibitory effects on the visual cortex depending on the Qigong methods practiced by different individuals.

Adult↗
PubMed1993

Serum lipoprotein (a) levels in maintenance hemodialysis patients.

To further understand lipoprotein (a) [Lp(a)] and atherosclerosis, we measured serum Lp(a), lipoprotein, and apolipoprotein levels in 55 patients (males, 24-73 years old) on maintenance hemodialysis, and compared them with those of 82 controls (males, 21-81 years old). The serum Lp(a) levels in patients on maintenance hemodialysis were significantly higher than those of the normal controls, while serum total cholesterol (TC), high-density lipoprotein-cholesterol, (HDL-C), HDL2-C, HDL3-C, apolipoprotein (apo) Al, apo All levels, and lecithin-cholesterol acyltransferase (LCAT) activities were significantly (p < 0.05) reduced in the patient group. The frequency distribution of serum Lp(a) levels in the patients was different from that in the control group, and no prognostic tendency of serum Lp(a) levels was noted by the etiology of renal failure as histologically determined by the renal biopsies. In the patient group, we also found that serum Lp(a) levels negatively correlated with serum triglycerides (TG) and total protein (TP) concentrations (p < 0.05), but no correlation was found between the duration of hemodialysis therapy or patient age and the serum levels of TC, TG, apo B and Lp(a) levels when tested for simple regression. Significant (p < 0.05) positive correlations were also found between TP and serum TG, apo B, and LCAT activities. These opposing tendencies of Lp(a) and serum TG, apo B, when measured against TP concentrations, indicate that serum TP levels may not affect serum lipoprotein and Lp(a) levels in the same direction. These data suggest that hemodialysis or end-stage renal disease itself, rather than hypoproteinemia, may hold the key to high serum Lp(a) levels in hemodialysis patients.

Adult↗
PubMed1993

Insulin receptor-related receptor messenger ribonucleic acid is focally expressed in sympathetic and sensory neurons and renal distal tubule cells.

The insulin receptor-related receptor (IRR) demonstrates striking structural homology to the insulin receptor (IR) and insulin-like growth factor-I receptor (IGFR), suggesting that IRR is a member of the IR family. However, the endogenous ligand and biological role for this "orphan" receptor are unknown. To identify potential sites of action for the IRR, in situ hybridization was employed to reveal cellular patterns of IRR gene expression in the developing and adult rat and in the adult human kidney. From embryonic days 15-20, IRR mRNA is most abundant in sensory neurons of the trigeminal and dorsal root ganglia and, to a lesser extent, neurons of the autonomic system. IRR gene expression diminishes in the majority of sensory neurons postnatally, but remains abundant in a subpopulation of adult rat trigeminal and dorsal root ganglion neurons. IRR mRNA is localized in peripheral autonomic ganglia localized in the adrenal medulla and renal hilum in the adult. From birth to maturity, IRR mRNA is abundant in renal epithelial cells focally localized in the distal tubule in both rat and human kidney. The specificity of this pattern of IRR gene expression was demonstrated by hybridization of serial tissue sections with two different nonoverlapping cRNA probes. Nonspecific signal, as measured by IRR sense probe hybridization, was negligible. This highly restricted pattern of IRR gene expression is in marked contrast to the very widespread pattern of gene expression demonstrated by the IR and IGFR. This study showed that IRR, IR, and IGFR mRNAs were colocalized in some sensory neurons, suggesting the possibility for hybrid receptor formation in these cells. In summary, IRR gene expression is focally localized in sensory and autonomic neurons and renal distal tubule cells. These observations suggest that the IRR, in contrast to the related IR and IGFR, serves a narrow cell-specific role.

Animals↗
PubMed1993

[The cytotoxicity of Sne-Pack periodontal dressing and scanning electron microscopic study]

We prepare a non-eugenol periodontal dressing Sne-pack(Sp),then investigated the effects of cess cytotxicity and observed the surface of materials on scanning electron of materials on scanning electron microscopy.The comparison results with Coe-pack (Cp) and zinc oxide-eugenol(Ce)showed that three materials have inconsiderable toxic effect on L-929 cell,the Sp and Cp dressing are smoother than Ce.

Journal Article↗
PubMed1993

[Morphogenesis of Bacillus sphaericus Ts-1 and formation of toxic proteins to mosquito larva].

The close relationships between morphogenesis of Bacillus sphaericus Ts-1 and formation of toxic proteins were studied systemically and comparatively by Enzyme-Linked Immunosorbent Assay, FITC-IgG Location and SDS-PAGE etc. This study showed that the toxic proteins of Ts-1 were produced in 8h culture at 30 degrees C. The toxicity increased steadily along with the sporification and then declined as the free spores increased greatly without collection immediately. It is suggested that substances homologous with crystal toxic proteins were situated on the cell walls.

Animals↗
PubMed1993

[Spitz nevus (report of 2 cases)].

This paper reports 2 cases of spitz nevus which appeared on the nose. Both patients were male, aged 3 and 33 years. The histopathologic characteristics showed compound nevus. One patient was treated by CO2 laser and the other by biopsy only. The patients were followed up for 3 and 9 months, respectively, ane no recurrence was found during these period.

Adult↗
PubMed1993

Effects of glaucocalyxin A on aggregation and cAMP levels of rabbit platelets in vitro.

Glaucocalyxin A (Gla A) is a new diterpenoid isolated from ethereal extract of the leaves of Rabdosia japonica (Burm f) Hara var glaucocalyx (Maxim) Hara (Labiatae) collected in Northeastern China. When incubated with washed rabbit platelets, Gla A inhibited ADP-, AA-, and PAF-induced aggregation of rabbit platelets with IC50 values of 3.44, 13.32, and 7.74 mumol.L-1, respectively. Gla A 10 and 100 mumol.L-1 increased the cAMP levels in platelets. In combination with imazodan hydrochloride, Gla A (1-100 mumol.L-1) caused a marked increase of platelet cAMP levels, while no effect with PGE1.

Animals↗