Biomedical subjects

C Yin

Publications and source records attributed to C Yin.

At least 37 records · Page 2Linked to original sources

PubMed1999

High major histocompatibility complex-unrestricted lysis of simian immunodeficiency virus envelope-expressing cells predisposes macaques to rapid AIDS progression.

Before the development of virus-specific immune responses, peripheral blood mononuclear cells (PBMC) from uninfected rhesus monkeys and human beings have the capacity to lyse target cells expressing simian immunodeficiency virus (SIV) or human immunodeficiency virus-1 (HIV) envelope (gp130 and gp120) antigens. Lysis by naive effector cells does not require major histocompatibility complex (MHC)-restricted antigen presentation, is equally effective for allogeneic and xenogeneic targets, and is designated MHC-unrestricted (UR) lysis. UR lysis is not sensitive to EGTA and does not require de novo RNA or protein synthesis. Several kinds of envelope-expressing targets, including cells that poorly express MHC class I antigens, can be lysed. CD4(+) effectors are responsible for most of the lytic activity. High lysis is correlated with high expression of HIV or SIV envelope, specifically, the central one-third of the gp130 molecule, and lysis is completely inhibited by a monoclonal antibody against envelope. Our work extends observations of human lymphocytes expressing HIV gp120 to the SIV/rhesus monkey model for AIDS. Additionally, we address the relevance of UR lysis in vivo. A survey of PBMC from 56 uninfected rhesus monkeys indicates that 59% of the individuals had peak UR lytic activity above 15% specific lysis. Eleven of these monkeys were subsequently infected with SIV. Animals with UR lytic activity above 15% specific lysis were predisposed to more rapid disease progression than animals with low UR lytic activity, suggesting a strong correlation between this form of innate immunity and disease progression to AIDS.

Animals↗

PubMed1999

Atm is dispensable for p53 apoptosis and tumor suppression triggered by cell cycle dysfunction.

Both p53 and ATM are checkpoint regulators with roles in genetic stabilization and cancer susceptibility. ATM appears to function in the same DNA damage checkpoint pathway as p53. However, ATM's role in p53-dependent apoptosis and tumor suppression in response to cell cycle dysregulation is unknown. In this study, we tested the role of murine ataxia telangiectasia protein (Atm) in a transgenic mouse brain tumor model in which p53-mediated apoptosis results in tumor suppression. These p53-mediated activities are induced by tissue-specific inactivation of pRb family proteins by a truncated simian virus 40 large T antigen in brain epithelium. We show that p53-dependent apoptosis, transactivation, and tumor suppression are unaffected by Atm deficiency, suggesting that signaling in the DNA damage pathway is distinct from that in the oncogene-induced pathway. In addition, we show that Atm deficiency has no overall effect on tumor growth and progression in this model.

Animals↗

PubMed1999

Dietary L-arginine attenuates expression of vascular cell adhesion molecule-1 in the aortae of hypercholesterolemic rats.

OBJECTIVE: To determine whether the antiatherogenic effect of L-arginine is due to an inhibition of vascular cell adhesion molecule-1 (VCAM-1) expression in the aortae of hypercholesterolemic rats. METHODS: Twenty-four male Wistar rats were randomized into three groups: Group NC with normal diet (NC, n = 8), Group CC with 4% cholesterol and 1% cholic acid diet (CC, n = 8), Group AC with 4% cholesterol and 1% cholic acid diet supplemented with 3% L-arginine HCl in the drinking water (AC, n = 8). Eight weeks later, the blood samples were collected for biochemical studies, and the aortae were harvested for RT-PCR and immunohistochemical studies. RESULTS: The results showed that dietary L-arginine supplementation reduced expression of VCAM-1 in protein level and mRNA level. CONCLUSION: Inhibitory effect of dietary supplementation of L-arginine on VCAM-1 expression may be one of the mechanisms of its antiatherosclerosis.

Animals↗

PubMed1999

[Determination of chlorogenic acid, glycyrrhizin and glycyrrhetinic acid in yinqiaojiedupian by high performance capillary electrophoresis].

A simple, rapid and reproducible capillary electrophoretic method was developed for the determination of chlorogenic acid, glycyrrhizin and glycyrrhetinic acid in Yinqiaojiedupian. The buffer solution used in this method was a mixture of 20 mmol/L NaH2PO4 and 5 mmol/L Na2B4O7(pH 7.0). The other conditions were as follows: applied voltage, 20 kV (positive to negative polarity); L = 60 cm; Leff = 55 cm; i.d. = 75 microns; lambda = 254 nm; temperature, 25 degrees C; injection time, 5 s hydrostatic. The linear calibration range was 1.568-100.4 mg/L for glycyrrhetinic acid, 8.000-128.0 mg/L for glycyrrhizin and 8.080-129.3 mg/L for chlorogenic acid, and recoveries were 98.0%-103% for glycyrrhetinic acid, 97.3%-102% for glycyrrhizin and 97.3%-100% for chlorogenic acid. The relative standard deviations (n = 3) were 0.2%-1.3% (intra-day) and 1.9%-3.0% (inter-day) for glycyrrhetinic acid, 0.5%-1.2%(intra-day) and 1.9%-2.1%(inter-day) for glycyrrhizin and 0.7%-1.3%(intra-day) and 1.6%-2.1%(inter-day) for chlorogenic acid. The contents of these three acids in Yinqiaojiedupian were successfully determined within 10 min.

Anti-Infective Agents↗

PubMed1999

[Diagnosis and prognosis evaluation of primary non-Hodgkin's lymphoma of the nose].

OBJECTIVE: To Study the diagnosis of primary nasal non-Hodgkin's Lymphoma (NHL) and to find the relationship between its classification, stage and prognosis. METHOD: The data of 10 cases with primary nasal NHL documented pathologically were analysed retrospectively. RESULT: The classification and stage were related to the prognosis significantly. Following up seven cases, 5T-ML with severe systemic symptoms died 4-6 months after diagnosis and treatment. One earlier T-ML is survival till now, and another B-ML was alive for 2.5 years. CONCLUSION: Early diagnosis of NHL of nose based on pathology is very important for treatment and prognosis. Repeat biopsies will be necessary when the diagnosis is suspected. The prognosis of late T-ML is disastrous.

Adolescent↗

PubMed1999

[Diagnosis and treatment of Killian's polyp under nasal endoscope].

OBJECTIVE: To further understand the advantage of examination and operation for killian's polyp under nasal endoscope. METHOD: 22 cases with Killian's polyps were diagnosed and treated under nasal endoscope. RESULT AND CONCLUSION: Before operation, examination under nasal endoscope may clearly find origin of the polyp and foci in maxillary sinus, which plays more important role in differential diagnosis and operation than CT or X-ray test. Operative treatment of Killian's polyp under nasal endoscope can not only eradicate foci but also reserve function of mucosa, but for severe foci in the maxillary sinus, the optimum operation should be Caldwell-Luc antrotomy.

Adolescent↗

PubMed1998

Experimental study on the correlation of nitric oxide with portal hypertensive enteropathy.

To explore the role of nitric oxide (NO) in the pathogenesis of portal hypertensive enteropathy (PHE), cirrhotic portal hypertension was induced in Wistar rats by subcutaneous administration of carbon tetrachloride. At the end of 12th week, NADPH-diaphorase staining was performed on ice frozen sections with the sample of fresh colonic tissues. NO synthase (NOS) activities and NOS mRNA expression of colonic tissues were investigated with chemoluminescence method and reverse transcription-polymerase chain reaction (RT-PCR), respectively. After NADPH-diaphorase histochemical staining, the computer image analysis and paired t test showed that NOS staining intensities of submucosal vascular endothelial cells and nerve fibers were all significantly higher in PHE group than those in normal group (P < 0.01 and P < 0.05, respectively), but the intensities of superficial epithelial cells were significantly lower than those of controls (P < 0.01). Chemoluminescence method demonstrated that general NOS activity of colonic mucosa was significantly higher in PHE group than that in control group (P < 0.01). Moreover, the degree of iNOS activity increase was greater than that of cNOS (104% vs 35%). RT-PCR revealed that NOS mRNA expressions were dramatically higher in PHE group than those in control group (P < 0.01). The results suggested that NO, with its property of vasodilatation, may be involved in the pathogenesis of vascular lesions of PHE in cirrhotic rats, and may also has something to do with mucosal lesions of colon in PHE.

Animals↗

PubMed1998

Key roles for E2F1 in signaling p53-dependent apoptosis and in cell division within developing tumors.

Apoptosis induced by the p53 tumor suppressor can attenuate cancer growth in preclinical animal models. Inactivation of the pRb proteins in mouse brain epithelium by the T121 oncogene induces aberrant proliferation and p53-dependent apoptosis. p53 inactivation causes aggressive tumor growth due to an 85% reduction in apoptosis. Here, we show that E2F1 signals p53-dependent apoptosis since E2F1 deficiency causes an 80% apoptosis reduction. E2F1 acts upstream of p53 since transcriptional activation of p53 target genes is also impaired. Yet, E2F1 deficiency does not accelerate tumor growth. Unlike normal cells, tumor cell proliferation is impaired without E2F1, counterbalancing the effect of apoptosis reduction. These studies may explain the apparent paradox that E2F1 can act as both an oncogene and a tumor suppressor in experimental systems.

Animals↗

PubMed1998

A common mechanism for illusory and occluded object completion.

New phenomena and results are reported that implicate a common contour interpolation mechanism in illusory and occluded (modal and amodal) object completion. In 3 experiments, a speeded classification task was used to study novel quasimodal displays in which occluded and illusory contours join. Results showed the same advantages in speed and accuracy over control displays for quasimodal, illusory, and occluded displays. The implications of quasimodal displays, along with another new display type in which contour linkages must precede determination of modal or amodal appearance, are considered. These logical considerations and empirical results suggest that amodal and modal completion depend on a common underlying mechanism that connects edges across gaps.

Adult↗

PubMed1998

Dissemination of lymphocytic choriomeningitis virus from the gastric mucosa requires G protein-coupled signaling.

The gastric mucosa is an important portal of entry for lymphocytic choriomeningitis virus (LCMV) infections. Within hours after intragastric (i.g.) inoculation, virus appears in the gastric epithelia, then in the mesenteric lymph nodes and spleen, and then in the liver and brain. By 72 h i.g.-inoculated virus is widely disseminated and equivalent to intravenous (i.v.) infection (S. K. Rai, B. K. Micales, M. S. Wu, D. S. Cheung, T. D. Pugh, G. E. Lyons, and M. S. Salvato. Am. J. Pathol. 151:633-639, 1997). Pretreatment of mice with a G protein inhibitor, pertussis toxin (PTx), delays LCMV dissemination after i.g., but not after i.v., inoculation. Delayed infection was confirmed by plaque assays, by reverse transcription-PCR, and by in situ hybridization. The differential PTx effect on i.v. and i.g. infections indicates that dissemination from the gastric mucosa requires signals transduced through heterotrimeric G protein complexes. PTx has no direct effect on LCMV replication, but it modulates integrin expression in part by blocking chemokine signals. LCMV infection of macrophages up-regulates CD11a, and PTx treatment counteracts this. PTx may prevent early LCMV dissemination by inhibiting the G protein-coupled chemotactic response of macrophages infected during the initial exposure, thus blocking systemic virus spread.

Animals↗

PubMed1998

[Detection of interleukin-2 receptor in patients with idiopathic thrombocytopenic purpura].

Using ELISA and indirect fluorescent antibody techniques(IFAT), the serum soluble inter-leukin-2 receptor(sIL-2R) and membrane IL-2R (mIL-2R) on lymphocyte cells induced by phyto-hemagglutinin (PHA) were studied in patients with idiopathic thrombocytopenic purpura (ITP). The results showed that the level of sIL-2R increased significantly before treatment and decreased after treatment; the percentages of mIL-2R induced by PHA decreased. There was no correlation between the level of serum sIL-2R and that of mIL-2R. Our observations suggest that increased level of serum sIL-2R in ITP patients may be one of causes evoking cellular immunological abnormalities.

Adolescent↗

PubMed1998

[Preliminary study of clinical scoring on prognosis of severe head-injury].

In this article, 68 cases of severly head-injured patients scoring and prognosis evaluation were reviewed. We have come to a practicable severe head injury index (SHII) for first aid: the blood pressure (Bp), pulse rate (P), respiration rate (R), degree of consciousness and reaction of the pupils are five items taken for estimation of the patients. The highest total score was 25, the lowest was 5. If the score was lasted for 2-4 hours below 7, and first aid non-responsive in 4-6 hours, the mortality and morbidity rates will be high. When the score is more than 14, the first aid salvage will be meaningful. The first aid salvage will be meaningful. The first aid had significant measing especially for those patients whose score was over 18. The detailed method of clinical scoring is shown on chart 2.

Adolescent↗

PubMed1998

[Study on relationship between detection of interleukin-6 and its mRNA and pregnancy induced hypertension].

OBJECTIVE: To investigate the effect of Interleukin-6 (IL-6) on pathogenesis of pregnancy induced hypertension (PIH) and to confirm the derivation of IL-6 and relationship between IL-6 and growth of placenta and fetus. METHODS: Pregnant women without infection and uterine contraction are divided into two groups: (1) PIH group (n = 57), (2) Normal pregnancy group (n = 15), reverse transcription-polymerase chain rection (RT-PCR) is used to detect IL-6 mRNA expression in leucocyto of peripheral blood and in placenta; Enzyme-linked immunosorbent assay (ELISA) is used to detect IL-6 level of peripheral blood and amniotic fluid. RESULTS: (1) The level of IL-6 and its mRNA in peripheral blood has a increasing trend as PIH degree. In moderate and severe PIH, IL-6 and its mRNA level are significantly higher than that of normal pregnancy. In each degree of PIH, IL-6 mRNA expression in placeata is significantly lower than that of normal pregnancy. In moderate and severe PIH, IL-6 level in amniotic fluid is significantly lower than that in normal pregnancy (P < 0.001). (2) In moderate and severe PIH, IL-6 level has high correlation to the IL-6 mRNA in peripheral blood (r = 0.67, P < 0.01). The IL-6 level in amniotic fluid has significant correlation to IL-6 mRNA in placenta (r = 0.79, P < 0.01). IL-6 and its mRNA in peripheral blood has no high correlation to IL-6 in amniotic fluid. (3) In severe PIH, the IL-6 mRNA in placenta and IL-6 level in amniotic fluid in the group of pregnancy with intrauterine growth retardation (IUGR) are both lower than that of the group without IUGR (P < 0.05). CONCLUSION: In PIH, the immune activity is rising, the IL-6 is overproduced by activated immune cells and it may involve in immune respond of organism and damage of vasicular endothelium. Decrease of IL-6 mRNA in placenta and IL-6 in amniotic fluid showes that the capability of production and transport of IL-6 decline in placenta of PIH patient, and these result in ischemia of placenta trophoblast and disturbance of the growth and development of placenta and fetus.

Amniotic Fluid↗

PubMed1998

[Choices of anesthesia in operations of extraction of foreign body in esophagus].

In order to probe the anesthetic methods of extracting foreign body in esophagus and improve operative effect, potentiated surface anesthesia and intratracheal intubation anesthesia were applied in operations to 72 cases of foreign bodies in esophagus, and comparative observations were done to these cases. All the cases had their foreign bodies extracted smoothly and no serious complications occurred. We consider that each anesthetic method has its advantage. The former is suitable for the adolescents and adults, the latter is suitable for the young children who have foreign bodies in esophagus and difficult breathing.

Adolescent↗

PubMed1998

[Effect of aloe-emodin on proliferation of vascular smooth muscle cells after arterial injury].

OBJECTIVE: To study the effect of Aloe-emodin (AE), an active ingredient of Rhubarb, on the kinetics of proliferation of smooth muscular cells (SMCs) cultured in vitro after rabbit iliac arterial injury. METHODS: Forty-eight hours after de-endothelialization (balloon endothelial denudation), the iliac arteries of the Japanese white rabbits were isolated and the smooth muscle cells were cultured primarily. AE was added to culture medium containing 10% fetal calf serum (FCS). The cultures were pulse-labeled with 3H-TdR and TdR uptake into VSMC were measured and the cell cycle of the cultures were analyzed by using flow cytometer. RESULTS: Compared with control, when the concentration gradient ranged from 10(-1) to 10(-5) g/L, the amount (cpm, count per minute) of 3H-TdR uptake into SMCs has significant differences (P < 0.05) and 10(-1) and 10(-2) g/L AE showed strong inhibitory effects on TdR uptake into VSMC and the percentage of inhibition [% inhibition = (cpm without AE - cpm with AE)/cpm without AE x 100%] was more than 90%. AE displayed concentration dependent inhibitory effects. The percentage of cells in G0/G1 phase was increased, but the percentage of cells in S phase was decreased in AE group, the transition of SMC cycle phase from G0 to S was blocked. CONCLUSIONS: AE is a strong inhibitor to the proliferation of SMCs and the pharmacological action of AE might reduce SMC proliferation in vivo and decrease intimal hyperplasia of restenosis.

Animals↗

PubMed1998

Differential messenger ribonucleic acid expression in aggressive versus linear periprosthetic osteolysis.

Osteolysis is a radiographic term used to describe bone resorption adjacent to prosthetic implants. This process involves a spectrum of radiographic presentations, from small generalized linear patterns (linear osteolysis) to larger erosive patterns (aggressive osteolysis). The tissue from aggressive osteolytic lesions from five patients were compared with a series of linear osteolytic lesions from five additional patients. Total ribonucleic acid was extracted from these tissue samples, followed by reverse transcription and amplification by the polymerase chain reaction using a series of primers intended to amplify all ribonucleic acid species. The polymerase chain reaction products were separated by gel electrophoresis and compared by side by side analysis (differential display techniques). Transcription initiation factor IIB and cytokine receptor CRFB4 messenger ribonucleic acid were expressed in four of five patients with aggressive osteolytic lesions, as compared with none of five patients with linear osteolytic lesions. Conversely, nonmuscle myosin heavy chain messenger ribonucleic acid was expressed in five of five patients with linear osteolysis, and in none of the five patients with aggressive osteolysis. Thus, there is a difference in cell behavior between linear and aggressive osteolytic lesions that likely accounts for differences in radiographic appearance. This disparity is likely attributable to differences in local conditions (greater amounts of debris, increasing instability of the implant, or increased fluid pressures within the osteolytic lesions), and differences in host response.

Cytokines↗

PubMed1997

Bax suppresses tumorigenesis and stimulates apoptosis in vivo.

The protein p53 is a key tumour-suppressor, as evidenced by its frequent inactivation in human cancers. Animal models have indicated that attenuation of p53-dependent cell death (apoptosis) can contribute to both the initiation and progression of cancer, but the molecular mechanisms are unknown. Although p53-mediated transcriptional activation is one possible explanation, none of the known p53-responsive genes has been shown to function in p53-dependent apoptosis. Here we test the role of the death-promoting gene bax in a transgenic mouse brain tumour, a model in which p53-mediated apoptosis attenuates tumour growth. Inactivation of p53 causes a dramatic acceleration of tumour growth owing to a reduction in apoptosis of over ninety per cent. We show that p53-dependent expression of bax is induced in slow-growing apoptotic tumours. Moreover, tumour growth is accelerated and apoptosis drops by fifty per cent in Bax-deficient mice, indicating that it is required for a full p53-mediated response. To our knowledge this is the first demonstration that Bax acts as a tumour suppressor, and our findings indicate that Bax could be a component of the p53-mediated apoptotic response in this system.

Animals↗

PubMed1997

The lymphocytosis-promoting agent pertussis toxin affects virus burden and lymphocyte distribution in the SIV-infected rhesus macaque.

Pertussis toxin from the gram-negative bacterium Bordetella pertussis is an ADP-ribosylase that modifies Gi proteins in mammalian lymphocytes and inhibits their capacity to traffic from blood into lymphoid tissues. We used this compound to induce lymphocytosis in rhesus macaques and to study its effects on SIV infection. Pertussis toxin injected at 25 micrograms/kg induced a transient lymphocytosis that peaked 3-8 days after administration and caused a rapid, transient decrease in the frequency of infectious cells in blood as judged by in vitro virus isolation assays. Lymphocyte subsets were altered during the lymphocytosis interval and sustained changes in CD8+ T cell levels were noted as long as 53 days after pertussis toxin injection. In situ hybridization studies showed that pertussis toxin altered the distribution of viral RNA in lymph nodes during the interval of lymphocytosis, and caused long-term changes with decreased virus replication in some tissue specimens.

Animals↗