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Biomedical subjects

R Cao

Publications and source records attributed to R Cao.

At least 55 records · Page 3Linked to original sources
PubMed1998

Vascular endothelial growth factor C induces angiogenesis in vivo.

Vascular endothelial growth factor C (VEGF-C) recently has been described to be a relatively specific growth factor for the lymphatic vascular system. Here we report that ectopic application of recombinant VEGF-C also has potent angiogenic effects in vivo. VEGF-C is sufficiently potent to stimulate neovascularization from limbal vessels in the mouse cornea. Similar to VEGF, the angiogenic response of corneas induced by VEGF-C is intensive, with a high density of new capillaries. However, the outgrowth of microvessels stimulated by VEGF-C was significantly longer than that induced by VEGF. In the developing embryo, VEGF-C was able to induce branch sprouts from the established blood vessels. VEGF-C also induced an elongated, spindle-like cell shape change and actin reorganization in both VEGF receptor (VEGFR)-2 and VEGFR-3-overexpressing endothelial cells, but not in VEGFR-1-expressing cells. Further, both VEGFR-2 and VEGFR-3 could mediate proliferative and chemotactic responses in endothelial cells on VEGF-C stimulation. Thus, VEGF-C may regulate physiological angiogenesis and participate in the development and progression of angiogenic diseases in addition to lymphangiogenesis.

Allantois↗
PubMed1998

[The effect of detrusor instability secondary to benign prostatic hypertrophy on the density of acetylcholinesterase-containing nerves].

OBJECTIVE: To study the effect of detrusor instability secondary to benign prostatic hypertrophy (BPH) on the density of cholinesterase-containing nerve in detrusor samples. METHOD: Our present study included 3 groups confirmed by urodynamic evaluation. They were control group (8 cases), obstructive detrusor stability group (7), and obstructive instability group (12). The specimens were obtained from the dome of bladder. The AchE-containing nerves were demonstrated by the method of Karnovsky-Roots staining and AchE silver staining. The density of AchE containing detrusor nerves in specimens was examined with sterologic techniques. RESULT: The density of AchE-containing nerves in the obstructive detrusor instability group and the stability group was significantly decreased as compared with the control group (P < 0.01). The density of AchE positive nerves were also significantly decreased in the obstructive instability group as compared with the obstructive stability group (P < 0.05). CONCLUSION: Detrusor instability secondary to BPH obstruction is related to the decrease of cholinergic innervation density in the detrusor muscles.

Acetylcholinesterase↗
PubMed1996

Receptor-mediated endothelial cell dysfunction in diabetic vasculopathy. Soluble receptor for advanced glycation end products blocks hyperpermeability in diabetic rats.

Dysfunctional endothelium is associated with and, likely, predates clinical complications of diabetes mellitus, by promoting increased vascular permeability and thrombogenicity. Irreversible advanced glycation end products (AGEs), resulting from nonenzymatic glycation and oxidation of proteins or lipids, are found in plasma, vessel wall, and tissues and have been linked to the development of diabetic complications. The principal means through which AGEs exert their cellular effects is via specific cellular receptors, one of which, receptor for AGE (RAGE), is expressed by endothelium. We report that blockade of RAGE inhibits AGE-induced impairment of endothelial barrier function, and reverse, in large part, the early vascular hyperpermeability observed in diabetic rats. Inhibition of AGE- and diabetes-mediated hyperpermeability by antioxidants, both in vitro and in vivo, suggested the central role of AGE-RAGE-induced oxidant stress in the development of hyperpermeability. Taken together, these data support the concept that ligation of AGEs by endothelial RAGE induces cellular dysfunction, at least in part by an oxidant-sensitive mechanism, contributing to vascular hyperpermeability in diabetes, and that RAGE is central to this pathologic process.

Adult↗
PubMed1996

Semiparametric approach to match probability calculations using single locus probes.

A semiparametric approach to match probability calculations using single locus probes has been developed and compared graphically with other standard methods by a one-sample simulation. The density functions obtained using this method are closer to the real distributions than those obtained by conventional approaches. Our method does not need to establish an arbitrary match threshold, which has been a source of problems in practical applications of standard methods. Moreover, it can be adjusted to any particular conditions by setting the experimental error and correlation of each laboratory. To assess the practical performance of this method we carried out a comparison experiment using a sample of 229 individuals analysed in duplicate.

Alleles↗
PubMed1996

Elevated plasma levels of vascular cell adhesion molecule-1 (VCAM-1) in diabetic patients with microalbuminuria: a marker of vascular dysfunction and progressive vascular disease.

Advanced glycation endproducts (AGEs), which accumulate in diabetic vasculature, result in enhanced expression of endothelial cell-associated vascular cell adhesion molecule-1 (VCAM-1) as well release of a soluble form of VCAM-1 (sVCAM-1) into culture supernatants. We hypothesized that sVCAM-1 in diabetic plasma might reflect early vascular perturbation in diabetic vasculopathy. Diabetic patients with microalbuminuria, a group with a high incidence of vascular complications, had increased plasma levels of sVCAM-1, approximately 1.5-fold greater than diabetic patients without microalbuminuria; P < 0.05. sVCAM-1 may be an indicator of ongoing cellular dysfunction in diabetes, as well as a dynamic surrogate marker for the effectiveness of therapeutic interventions.

Albuminuria↗
PubMed1996

Advanced glycation endproducts (AGEs) induce oxidant stress in the gingiva: a potential mechanism underlying accelerated periodontal disease associated with diabetes.

We hypothesized that one mechanism underlying advanced periodontal disease in diabetes may involve oxidant stress in the gingiva, induced by the effects of Advanced Glycation Endproducts (AGEs), the irreversible products of non-enzymatic glycation and oxidation of proteins and lipids which accumulate in diabetic plasma and tissue. Infusion of AGE albumin, a prototypic ligand, into mice resulted in increased generation of thiobarbituric acid reactive substances (TBARS) compared with infusion of non-glycated albumin in the gingiva, as well as in the lung, kidney and brain. Pretreatment of the animals with the antioxidants probucol or N-acetylcysteine (NAC) prevented the generation of TBARS in the gingiva. Affinity-purified antibody to AGEs demonstrated increased immunoreactivity for AGEs in the vasculature and connective tissues of the gingiva in streptozotocin-induced diabetic mice compared to non-diabetic controls. Increased immunoreactivity for AGEs was also demonstrated in the gingiva of diabetic humans compared with non-diabetic individuals via immunohistochemistry and ELISA. Consistent with these data, immunohistochemistry for heme oxygenase-1, a marker of enhanced oxidant stress, was increased in the gingival vasculature of diabetic mice and humans compared with non-diabetic controls. These data suggest that AGEs present in diabetic gingiva may be associated with a state of enhanced oxidant stress, a potential mechanism for accelerated tissue injury.

Adult↗
PubMed1996

RAGE: a novel cellular receptor for advanced glycation end products.

Exposure of proteins to reducing sugars results in nonenzymatic glycation with the ultimate formation of advanced glycation end products (AGEs). One means through which AGEs modulate cellular functions is through binding to specific cell surface acceptor molecules. The receptor for AGEs (RAGE) is such a receptor and is a newly identified member of the immunoglobulin superfamily expressed on endothelial cells (ECs), mononuclear phagocytes (MPs), and vascular smooth muscle cells (SMCs) in both vivo and in vitro. Binding of AGEs to RAGE results in induction of cellular oxidant stress, as exemplified by the generation of thiobarbituric acid-reactive substances, expression of heme oxygenase type I, and activation of the transcription factor NF-kB, with consequences for a range of cellular functions. AGEs on the surface of diabetic red cells enhance binding to endothelial RAGE and result in enhanced oxidant stress in the vessel wall. By using reagents to selectively block access to RAGE, the role of this receptor in AGE-mediated perturbation of cellular properties can be dissected in detail.

Animals↗
PubMed1995

The receptor for advanced glycation end products (RAGE) is a cellular binding site for amphoterin. Mediation of neurite outgrowth and co-expression of rage and amphoterin in the developing nervous system.

The receptor for advanced glycation end products (RAGE), a newly-identified member of the immunoglobulin superfamily, mediates interactions of advanced glycation end product (AGE)-modified proteins with endothelium and other cell types. Survey of normal tissues demonstrated RAGE expression in situations in which accumulation of AGEs would be unexpected, leading to the hypothesis that under physiologic circumstances, RAGE might mediate interaction with ligands distinct from AGEs. Sequential chromatography of bovine lung extract identified polypeptides with M(r) values of approximately 12,000 (p12) and approximately 23,000 (p23) which bound RAGE. NH2-terminal and internal protein sequence data for p23 matched that reported previously for amphoterin. Amphoterin purified from rat brain or recombinant rat amphoterin bound to purified sRAGE in a saturable and dose-dependent manner, blocked by anti-RAGE IgG or a soluble form of RAGE (sRAGE). Cultured embryonic rat neurons, which express RAGE, displayed dose-dependent binding of 125I-amphoterin which was prevented by blockade of RAGE using antibody to the receptor or excess soluble receptor (sRAGE). A functional correlate of RAGE-amphoterin interaction was inhibition by anti-RAGE F(ab')2 and sRAGE of neurite formation by cortical neurons specifically on amphoterin-coated substrates. Consistent with a potential role for RAGE-amphoterin interaction in development, amphoterin and RAGE mRNA/antigen were co-localized in developing rat brain. These data indicate that RAGE has physiologically relevant ligands distinct from AGEs which are likely, via their interaction with the receptor, to participate in physiologic processes outside of the context of diabetes and accumulation of AGEs.

Animals↗
PubMed1995

Advanced glycation endproducts interacting with their endothelial receptor induce expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured human endothelial cells and in mice. A potential mechanism for the accelerated vasculopathy of diabetes.

Vascular cell adhesion molecule-1 (VCAM-1), an inducible cell-cell recognition protein on the endothelial cell surface (EC), has been associated with early stages of atherosclerosis. In view of the accelerated vascular disease observed in patients with diabetes, and the enhanced expression of VCAM-1 in diabetic rabbits, we examined whether irreversible advanced glycation endproducts (AGEs), could mediate VCAM-1 expression by interacting with their endothelial cell receptor (receptor for AGE, RAGE). Exposure of cultured human ECs to AGEs induced expression of VCAM-1, increased adhesivity of the monolayer for Molt-4 cells, and was associated with increased levels of VCAM-1 transcripts. The inhibitory effect of anti-RAGE IgG, a truncated form of the receptor (soluble RAGE) or N-acetylcysteine on VCAM-1 expression indicated that AGE-RAGE-induced oxidant stress was central to VCAM-1 induction. Electrophoretic mobility shift assays on nuclear extracts from AGE-treated ECs showed induction of specific DNA binding activity for NF-kB in the VCAM-1 promoter, which was blocked by anti-RAGE IgG or N-acetylcysteine. Soluble VCAM-1 antigen was elevated in human diabetic plasma. These data are consistent with the hypothesis that AGE-RAGE interaction induces expression of VCAM-1 which can prime diabetic vasculature for enhanced interaction with circulating monocytes.

Animals↗
PubMed1995

[Mortality study of cancer among Anshan iron and steel workers].

Cancer mortality in the period between 1971 and 1988 was surveyed among 71,803 male workers at thirty two major plants in Anshan Iron and Steel Corporation. A total of 5,896 deaths was registered. Cancer deaths occurred in 1,830, accounting for 31.04% of all deaths. The five leading cancers were that of lung, liver, stomach, esophagus and intestine. Cancer death rate increased with age and with calender year. The SMR for all cancers and for the cancer of lung, stomach and esophagus indicated significant excess (P < 0.01). 77.49% of all cancer deaths, and 82.82% of deaths with lung cancer occurred in smokers. The findings show that the mortality of cancer amongiron and steel workers in Anshan was the leading cause of death, and the death rate was higher than that of local and large city population such as in Beijing, Shanghai, etc. The excess cancer rate, especially that of lung cancer, may be related to carcinogenic agents in the working environment and smoking habit.

Adult↗
PubMed1994

Receptor for advanced glycation end products (AGEs) has a central role in vessel wall interactions and gene activation in response to circulating AGE proteins.

The extended interaction of aldoses with proteins or lipids results in nonenzymatic glycation and oxidation, ultimately forming AGEs, the presence of which in the plasma and vessel wall is associated with diabetic vascular complications. We show here that AGE albumin in the intravascular space interacts with the vessel wall via binding to an integral membrane protein, receptor for AGE (RAGE), a member of the immunoglobulin superfamily, resulting in clearance from the plasma and induction of interleukin 6 mRNA. Intravenously infused 125I-AGE albumin showed a rapid phase of plasma clearance with deposition in several organs. Rapid removal of 125I-AGE albumin from the plasma was prevented by administration of a soluble, truncated form of RAGE, which blocked binding of 125I-labeled AGE albumin to cultured endothelial cells and mononuclear phagocytes, as well as by pretreatment with anti-RAGE IgG. Ultrastructural studies with AGE albumin-colloidal gold conjugates perfused in situ showed that in murine coronary vasculature this probe was taken up by endothelial plasmalemmal vesicles followed by transport either to the abluminal surface or by accumulation in intracellular vesicular structures reminiscent of endosomes and lysosomes. Consequences of AGE-RAGE interaction included induction of interleukin 6 mRNA expression in mice. These data indicate that RAGE mediates the interaction of AGEs with the vessel wall, both for removal of these glycated proteins from the plasma and for changes in gene expression.

Animals↗
PubMed1994

The endothelial cell binding site for advanced glycation end products consists of a complex: an integral membrane protein and a lactoferrin-like polypeptide.

Advanced glycation end products (AGEs), formed as the result of the extended interaction of proteins with ketoses, modulate central properties of endothelial cells and mononuclear phagocytes by interacting with a cell surface binding site comprised of a novel integral membrane protein (receptor for AGE = RAGE) and a lactoferrin-like polypeptide (LF-L), the latter having sequence identity to lactoferrin (LF). To further understand this cellular binding site, the interaction of RAGE with LF-L and LF was characterized. By ligand blotting and a solid state competitive binding assay, 125I-LF-L and 125I-LF bound to RAGE immobilized on nitrocellulose membranes or polypropylene tubes in a time-dependent and reversible manner, demonstrating a high affinity component with Kd approximately 100 pM. The interaction of 125I-LF-L and 125I-LF with RAGE was independent of iron in LF and was competed by addition of an excess of unlabeled carboxyl-terminal portion of LF. Cross-linking studies with purified 125I-LF-L and RAGE, in the presence of disuccinimidyl suberate, showed a new, slowly migrating band, corresponding to a complex of RAGE and LF-L, and cross-linking on mouse aortic endothelial cells showed two new slowly migrating bands on immunoblotting visualized with both anti-RAGE IgG and anti-LF-L IgG. These data lead us to propose that the endothelial cell surface binding site for AGEs consists of LF-L bound noncovalently to RAGE anchored in the cell membrane.

Amino Acid Sequence↗
PubMed1993

Population genetics of three VNTR polymorphisms in two different Spanish populations.

Two different Spanish populations, one from Galicia (NW Spain) and the other from the rest of Spain, have been analyzed at three different hypervariable loci (YNH24, MS43a and MS31) using the EDNAP electrophoretic protocol and HinfI as restriction enzyme. Although the "rest of Spain" population is a clearly stratified population using classical blood groups, no evidence of stratification for these loci has been found and the differences to the Galician population were not significant, which suggests that a common Spanish population data-base could be possible. A semiparametric model is proposed for estimating frequencies, using the smoothed cross-validation of Hall et al. (1992) to calculate the size of the window utilized.

Alleles↗
PubMed1992

[Re-discovery of yinzhou chaihu].

This paper deals with the distribution, original plant, course of rise and fall in drug market and quality of Yinzhou Chaihu, which was once regarded as a fine sort of Chinese drug Chaihu (Radix Bupleuri) in ancient times. Further research on this medicinal plant is suggested to facilitate its re-exploitation and utilization.

China↗