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Biomedical subjects

B Yang

Publications and source records attributed to B Yang.

At least 343 records · Page 19Linked to original sources
PubMed1995

Oxidized low-density lipoproteins facilitate leukocyte adhesion to aortic intima without affecting endothelium-dependent relaxation. Role of P-selectin.

Inflammatory cell deposition in atherosclerotic blood vessels has been thought to relate to loss of endothelium-derived nitric oxide (NO). To examine whether cell deposition correlates temporally with the loss of NO activity, rat aortic rings were incubated with buffer, native LDL (n-LDL), oxidized LDL (ox-LDL), or the endothelium-derived relaxing factor synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) for 2 hours, and vascular contractile response to norepinephrine and relaxant response to acetylcholine, thrombin, and calcium ionophore A23,187 were examined. Thereafter, the rings were exposed to biotin-fluorescein isothiocyanate-labeled fluorescent or unlabeled leukocytes for 30 minutes. Cell adhesion was quantitated by fluorescent microscopy as well as by scanning electron microscopy. Incubation with n-LDL or ox-LDL did not affect either the contractile or the relaxant response of rings. However, leukocyte adhesion increased markedly in all ox-LDL-treated rings but not in those treated with n-LDL. Thus, leukocyte adhesion occurred independent of NO activity. In keeping with this concept, pretreatment of rings with the NO precursor L-arginine failed to influence leukocyte adhesion to rings incubated with ox-LDL. Treatment of rings with L-NAME also resulted in adhesion of a large number of leukocytes. Furthermore, all rings treated with ox-LDL or L-NAME demonstrated marked expression of P-selectin leukocyte adhesion molecules, determined by immunohistochemistry. Pretreatment of rings with the P-selectin blocking antibody PB1.3 markedly decreased deposition of leukocytes in rings exposed to ox-LDL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Migration of bovine aortic smooth muscle cells after wounding injury. The role of hyaluronan and RHAMM.

The migration of smooth muscle cells is a critical event in the pathogenesis of vascular diseases. We have investigated the role of hyaluronan (HA) and the hyaluronan receptor RHAMM in the migration of adult bovine aortic smooth muscle cells (BASMC). Cultured BASMC migrated from the leading edge of a single scratch wound with increased velocity between 1 and 24 h. Polyclonal anti-RHAMM antisera that block HA binding with this receptor abolished smooth muscle cell migration following injury. HA stimulated the random locomotion of BASMC and its association with the cell monolayer increased following wounding injury. Immunoblot analysis of wounded monolayers demonstrated a novel RHAMM protein isoform that appeared within one hour after injury. At the time of increased cell motility after wounding, FACS analysis demonstrated an increase in the membrane localization in approximately 25% of the cell population. Confocal microscopy of injured monolayers confirmed that membrane expression of this receptor was limited to cells at the wound edge. Collectively, these data demonstrate that RHAMM is necessary for the migration of smooth muscle cells and that expression and distribution of this receptor is tightly regulated following wounding of BASMC monolayers.

Animals↗
PubMed1995

Signal transduction mechanisms in substance P-mediated ciliostimulation.

Substance P is a neuropeptide released by afferent neurons in the respiratory tract during inflammatory reactions. It produces effects on blood vessels, bronchial smooth muscle, nasal glands, and respiratory cilia. We studied the in vitro effect of substance P on the ciliary beat frequency of human adenoid explants and its mechanism of action. Substance P was added to cultured adenoid at concentrations of 10(-10), 10(-8), 10(-6), and 10(-4) mol/L. Ciliary beat frequency was determined with phase-contrast microscopy and microphotometry. Substance P increased ciliary beat frequency a maximum of 11.9% +/- 3.8% (p < 0.01). Diclofenac (10(-6) mol/L) significantly blocked the ciliostimulatory effects of SP (p < 0.022), indicating that prostaglandin synthesis is an intermediate step in the action of substance P on ciliary beat frequency. The L-arginine analogs, NG-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine, inhibit nitric oxide synthesis from L-arginine. L-Arginine analogs (10(-4) to 10(-2) mol/L) inhibited the effect of substance P (p < 0.02 at the higher concentration). This inhibition was reversed by adding L-arginine, demonstrating that nitric oxide production is a required step in substance P-induced ciliostimulation. Substance P stimulates ciliary activity in human nasal mucosa as a result of secondary production and release of endogenous prostaglandins and nitric oxide. It is likely that inflammatory disease processes that stimulate release of substance P and subsequent prostaglandin and nitric oxide production modify mucociliary transport. Pharmacologic modification of substance P and its second messengers may eventually permit regulation of this important defense mechanism and control of neurogenic inflammation.

Adenoids↗
PubMed1995

Social stress and suicide: replicating an Asian study with American data.

A study purporting to show an association between social stress and attempted suicide in Hong Kong utilized an incorrect regression specification. The study was replicated with American time-series data and, using the correct specification, social stress was positively associated with suicide rates.

Cross-Cultural Comparison↗
PubMed1995

Only children and children with siblings in the People's Republic of China: levels of fear, anxiety, and depression.

In 1979, China implemented its one-child-per-family policy in order to control its burgeoning population. Subsequently, concern has been raised about the policy and its potentially negative effects on children. In the present study, we examined these presumed effects on 202 adolescents born before the policy went into effect, 290 preadolescents born during the period in which the policy was being implemented, and 239 children who were born after the policy went into effect. Measures of fear, anxiety, and depression were obtained. Contrary to our hypotheses, based on concerns raised by the one-child policy, children with siblings reported significantly higher levels of fear, anxiety, and depression than only children, regardless of when they were born. For depression, this effect was qualified by a sibling status x age interaction. Children with siblings born after the policy went into effect, or during its implementation, reported higher levels of depression than did only children; however, only children and children with siblings born before the policy went into effect did not differ significantly from one another. Sociocultural factors associated with these findings are explored.

Adolescent↗
PubMed1995

Immunoregulatory effects of the herba Epimediia glycoside icariin.

The in vitro effects of the Chinese Herba Epimediia glycoside icariine (ICA), a chinese herbal extract, on human immune responses were investigated. ICA induced a weak and delayed proliferation of peripheral blood mononuclear cells from healthy donors when compared to phytohemagglutinin. Both T- (TCR alpha beta+) and B cells were the ICA-responding cells. Within T-cells, the relative proportion of CD4-8+ cells increased but that of CD4+8- cells decreased. ICA in certain concentrations could increase lymphokine-activated killer cell (LAK) activity (0.1 to 1.0 microgram/ml) in both tumor patients and healthy donors, and natural killer cell (NK) activity (1.0 to 5.0 micrograms/ml) in tumor patients. Moreover, ICA stimulated the production of tumor necrosis factor-alpha in monocytes from healthy donors. These findings provide evidence that ICA could be applied to adoptive immunotherapy. Generation of LAK cells in presence of an appropriate dose of ICA might be superior to interleukin-2 alone.

Adjuvants, Immunologic↗
PubMed1995

Eradication of poliomyelitis: progress in the People's Republic of China.

China and the other countries of the Western Pacific Region have a goal of eradication of wild poliovirus by the end of 1995. In this report we examine the progress made toward eradication through the end of 1993. We examined the information about poliomyelitis and wild poliovirus based on the acute flaccid paralysis surveillance system. The number of reported poliomyelitis cases decreased from 4623 cases in 1989 and 5065 cases in 1990, which occurred during a large nationwide poliomyelitis epidemic, to 538 cases in 1993. Mass supplemental immunization sessions were conducted during the 1991 to 1992 and 1992 to 1993 winters. After the two rounds of supplemental immunizations in the 1992 to 1993 winter, wild poliovirus was not detected for the subsequent 21 months in 22 contiguous provinces in central and northern China, in which 980 million persons reside. In 1993 wild poliovirus was detected in only 5 provinces in southern China and in 2 provinces in the remote Western region; these provinces have only 14% of the total population in China. China is close to achieving its 1995 poliomyelitis elimination goal. Mass supplemental immunizations in children 0 to 3 years old can rapidly eliminate wild poliovirus from large, very densely populated areas, low income rural areas and remote mountainous areas. There appears to be no technical obstacle, even in the most difficult areas, to achieving global eradication of wild poliovirus by the year 2000.

Child↗
PubMed1995

[An investigation of medicinal Trichosanthes].

This paper reports the distribution, habitats and medical usages of 14 species of medicinal Trichosanthes produced in China. Among them, there is a new species named Trichosanthes mianyangensis. A key for the identification of all these 14 species has been compiled and presented.

China↗
PubMed1995

[The significance of dynamic change of plasma endothelin level in epidemic hemorrhagic fever].

One hundred and twenty nine hospitalized cases of epidemic hemorrhagic fever (EHF) diagnosed and classified according to the protocol of prevention and treatment of this disease approved by the Ministry of Health in 1987 were studied to ascertain the role of endothelin (ET) in the etiology. 30 healthy adult subjects residing in the same area served as control. Blood samples were collected and plasma ET level was measured with radioimmunoassay and its dynamic change noted. It is shown that plasma ET level of the EHF patients was higher in febrile, hypotensive or shock, oliguric and transitional stages than that of controls. However, the level returned to normal in polyuric stage. Plasma ET level was also highly positively correlated with that of Tamm-Horsfall protein (THP) and beta 2 microglobulin. The higher the level of plasma ET, the poorer the ontcome. It is suggested that ET plays an important role in the epidemiology of EHF and monitoring of plasma ET level will be of help not only in predicting the prognosis, but also in guiding the clinical therapy.

Adolescent↗
PubMed1995

[Protective effects of liu tea on CCl4 injured liver and its working mechanism].

Liu Tea can effectively prevent the elevation of SGPT and SGOT induced by CCl4 in mice, reduce MDA and elevate GSH and GSH-px levels. It also induces the anabolism of microsomal protein and hepatocyte microsomal cytochrome P-450. These results suggest that Liu Tea has protective effects on the liver, which may be related to the clearing of free radicals and inhibition of lipid peroxidation.

Animals↗
PubMed1995

[A modified esophagogastrostomy: report of 528 patients].

The nearby tissues were used to cover the esophagogastric anastomotic stoma in 528 patients with esophageal and cardiac cancer undergoing resection. After interrupted suturing of the whole layer of esophagus and stomach, the paracervicalis was anastomosed with the capsule of the thyroid gland to strengthen the anterior wall of the anastomotic stoma. In case the anastomosis is done alove the arch of aorta, a flap of pedicled plewa is produced to cover the upper frigonum. The lower ligamentum pulmonale was used to coner the anastomosis when it is performed subaoticolly. No anastomotic leakage and stenosis were found in 528 patients in the follow-up of 2-5 years.

Adult↗
PubMed1995

[Determination of bakuchiol in the fruit of Psoralea corylifolia L].

A GC method for the determination of bakuchiol of described. GC conditions for analysing are as follows: stationary phase: SE-30: injector temperature: 250 degrees C: column temperature: 200 degrees C and detector: FID. The linear range of this method is 0.24-2.4 micrograms and the average recovery is 98.82%, with a relative standard deviation of 1.58%. This method has been successfully used to determine the content of bakuchiol in the samples on the market in 11 different areas, the contents being 1%-7%.

Chromatography, Gas↗
PubMed1995

[Narrowing of nasopharyngeal port for rhinolalia aperta in children].

This article describes a method of treating children with rhinolalia aperta by surgically narrowing the nasopharyngeal port. Eleven cases were operated on. The relationship between the palatopharyngeal structure and the phonology, the criteria for case selection and the evaluation of results were studied by the lateral nasopharyngeal X-ray films, videorecord of the nasopharynx, sonagram analysis and nasometer examination, the factors affecting treatment results has been analyzed clinically.

Child↗
PubMed1994

Initiation of transcription at the human terminal deoxynucleotidyl transferase gene promoter: a novel role for the TATA binding protein.

Control of initiation of transcription of the human terminal deoxynucleotidyl transferase (TdT) gene was investigated by using an in vitro transcription assay. The precise contribution of discrete basal promoter elements to transcription initiation was determined by testing deletion and substitution mutations. The primary element, contained within the region spanning -34 to -14 bp relative to the transcription start site, accounted for 80% of basal promoter activity. TdT promoter activity required the sequence ACCCT at -24 to -20 bp since a dramatic decrease in transcription initiation was observed after mutation of this sequence, whereas mutation of the adjacent sequence from -32 to -25 bp did not alter promoter activity. The secondary element contained sequences surrounding the transcription start site and had 20% of promoter activity. Deletion of both elements completely abolished transcription initiation. Initiator characteristics of the secondary element were revealed by using the in vitro assay: promoter sequences at the transcription start site were sufficient to direct accurate initiation at a single site. Mutation of the sequence GGGTG spanning the transcription start site resulted in loss of transcription initiation. Both the primary and secondary elements were nonhomologous to corresponding regions from the mouse TdT gene promoter. While the human basal promoter functioned in the absence of TATA consensus sequences or GC-rich SP1 binding sites, it was dependent on active TFIID. In contrast to other TATA-less promoters, purified TATA binding protein substituted for the TFIID complex and restored promoter activity to TFIID-inactivated nuclear extracts.

Base Sequence↗
PubMed1994

Identification of a tripartite basal promoter which regulates human terminal deoxynucleotidyl transferase gene expression.

In order to locate the promoter region of the human terminal deoxynucleotidyl transferase gene, serially truncated segments of the 5'-flanking region of the gene were cloned into a chloramphenicol acetyltransferase reporter vector. Transient transfection analyses of the terminal transferase-reporter gene constructs identified the basal promoter region within -34 to +40 base pairs relative to the transcription start site. Three promoter elements were defined in this region. The primary element is within 34 base pairs upstream of the transcription start site. The CAP site is 62 base pairs upstream of the translation start site. The secondary element involves sequences around the transcription start site. The third is located 25 base pairs downstream from the initiation site (+25 to +40). This tripartite basal promoter was not tissue specific; similar patterns of promoter activity were observed in terminal transferase expressing and non-expressing cells. Transfection analyses also indicated the presence of negative regulatory elements upstream of the basal promoter region, and these elements were preferentially active in cells expressing terminal transferase.

Base Sequence↗