Biomedical subjects

M Jiang

Publications and source records attributed to M Jiang.

At least 145 records · Page 8Linked to original sources

PubMed1997

[Study on p53, mdm-2 and p21WAF1 protein expression in ER-positive and ER-negative human breast cancer cell lines and its relation to biological features].

OBJECTIVE: To study p53, mdm-2 and p21WAF1 protein expression levels in ER-positive and ER-negative human breast cancer cell lines and their relations to biological features. METHODS: Using cell culture, DNA stable transfection and immunohistochemical methods, the protein expression levels of p53, mdm-2 and WAF1 genes in ER-positive expressing wtp53 MCF-7 cells, ER-negative expressing mtp53 MDA-MB-231 cells and ER-transfected MDA-MB-231 cells were determined, and then, their relation to biological features were compared. RESULTS: (1) The function and expression of p53 protein of MCF-7 and MDA-MB-231 cells were obviously different. The expression levels of mdm-2 and p21WAF1 proteins in MCF-7 cells were higher than those of MDA-MB-231 cells (P < 0.05), The biological features of the former were more favorable than those of the latter. (2) The ER-transfected MDA-MB-231 cells showed lower expression of mtp53 and higher expression of mdm-2 protein (P < 0.05), but no significant difference from that of p21WAF1 protein (P > 0.05). Meanwhile, biological features leading to favorable prognosis were manifested. CONCLUSION: The ER status of breast cancer cell lines is related to the expression level of p53 and mdm-2 proteins and the biological features.

Breast Neoplasms↗

PubMed1997

[Clinical observation of trabeculectomy without conjunctival incision].

OBJECTIVE: To reduce the formation of cicatrization of filtering bleb and elevate the successful rate of filtration surgery of glaucoma. METHODS: Trabeculectomy without conjunctival incision was performed on 37 eyes of 35 patients with glaucoma. RESULTS: They were followed up for 3-16 months. The rate of control of the intraocular pressure was 94.6%, and the operative complications were few and mild. CONCLUSION: The results show that the trabeculectomy without conjunctival incision is a safe and effective anti-glaucoma technique.

Adult↗

PubMed1997

[Effects of endogenous beta-adrenoceptor agonist on lung edema in scalded rats].

The effect of endogenous beta-adrenoceptor agonist on lung edema in scalded rats were investigated. The results showed that lung water content, wet/dry lung weight ration, bronchoalveolar lavage (BAL) protein concentration, malondialdehyde (MDA) content and leukocyte count in scalded and PPN treated rats were obviously higher than hose in control rats. The above parameters in scalded rats pretreated with PPN were even much higher than those of control and tended to be higher than burn group. It is suggested that endogenous beta-agonist is effective in the prevention of lung edema and lipid peroxidation, and it acts as an important anti-inflammatory factor in vivo.

Adrenergic beta-Agonists↗

PubMed1997

[Comparison of radiographs and magnetic resonance imaging in the detection of sacroiliitis in patients with ankylosing spondylitis].

The role of radiography and magnetic resonance (MR) imaging in the detection of sacroiliitis in patients with ankylosing spondylitis (AS) was compared in this study. Thirty-six sacroiliac joints in 18 patients with AS were examined with radiography and MR scan. MR images were performed with the sequence of the coronal T1 weighted image, T2 weighted image, and T2* weighted image. Images of all patients were graded according to the modified New York criteria. Statistical results showed that significant differences existed between MR imaging and radiography in the detection of sacroiliitis (P < 0.01). MR imaging was superior to plain film radiographs in visualising erosions (P < 0.01). Radiography cannot reveal the cartilage changes and bone marrow oedema, which can only be seen in MR images. In the absence of radiographic changes, MR imaging can provide objective and complementary findings of sacroiliitis in patients with AS. Due to the ability to image cartilage changes and bone marrow oedema directly, MR imaging may be particularly useful in early diagnosis of sacroiliitis. For patients without any changes on sacroiliac joint radiograph, further examination of MR imaging may be advisable.

Adolescent↗

PubMed1997

[Detection of antineutrophil cytoplasmic antibodies for the values of Wegener's granulomatosis diagnosis and activity judgment].

OBJECTIVE: To investigate the clinical significance of antineutrophil cytoplasmic antibodies (ANCA) in Wegener's granulomatosis (WG) and other diseases. METHOD: Indirect immunofluorescence was applied to detect serum ANCA of 204 patients and 48 normal controls. Enzyme-linked immunosorbent assay (ELISA) was used to detect antimyeloperoxidase (MPO) antibodies. RESULTS: The frequency of ANCA in sera of WG patients was 75% and significantly higher than those in sera of other groups (P < 0.05). ELISA demonstrated that MPO was the major antigen recognized by perinuclear ANCA (P-ANCA). Cytoplasmic ANCA (C-ANCA) was always positive and high titers in sera of active WG patients, but turned to negative or low titers in remission. CONCLUSION: These results suggested that C-ANCA was specific for WG and was a marker for disease activity in WG. P-ANCA wasn't specific for WG, but related to vasculitis.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed1997

[In situ DNA labeling apoptosis in breast cancer as related to prognosis].

OBJECTIVE: This study was undertaken to determine the expression of apoptosis in breast cancer and to evaluate it's significance as a prognostic marker. METHODS: A series of 91 invasive breast cancer was analysed for the expression of apoptosis by using the 3-end-labeling method of DNA in tissue sections. The apoptotic indexes were the percentages of apoptotic cells among tumor cells. RESULTS: The end-labeling method allowed a precise evaluation of the expression of apoptosis. Apoptosis occurred in 91.2% of breast cancer patients, and apoptotic indexes were divided into two groups, 0-0.21 and 0.28-0.62. Low apoptotic index was related to axillary lymph node metastasis (P < 0.01). In survival analysis, higher apoptotic index was related to disease free survival (P = 0.0095) and overall survival (P = 0.0348) in the entire cohort. Cox's analysis showed apoptotic index had no independent prognostic value. CONCLUSION: The apoptosis was a spontaneous phenomenon in breast cancer tissue, and the expression was different from each other. Further analysis was needed to clarify the relationship between apoptosis and prognosis, especially the response to adjuvent therapy.

Adult↗

PubMed1997

[Inhibition of estrogen receptor-positive human breast carcinoma cell growth by retinoic acid].

OBJECTIVE: To evaluate whether the growth inhibition by retinoic acid and RAR alpha mRNA expression levels were affected by the change of ER expression. METHODS: The ER-negative breast cancer cell line MDA-MB-231 was transfected with the ER gene by stable transfection. RESULTS: In ER-transfected cells not only was the RAR alpha mRNA expression increased, but their growth was inhibited by retinoic acid as well. Estrogen could greatly stimulate the RAR alpha gene expression not only in established ER-positive cell lines but also in ER-transfected MDA-MB-231 cells. CONCLUSION: Our data strongly suggest that ER-mediated enhancement of RAR alpha levels play an important role in RA inhibition of human breast cancer cell growth.

Antineoplastic Agents↗

PubMed1997

Estrogen receptor-negative breast cancer cells transfected with estrogen receptor exhibit decreased tumour progression and sensitivity to growth inhibition by estrogen.

Breast cancer containing estrogen receptors (ER) are responsive to antiestrogen treatment and have a better prognosis compared with ER-negative tumors. The loss of estrogen receptors appears to be associated with a progression to less-differentiated cells. We transfected the human ER into the ER-negative breast cancer cell line MDA-MB-231 cells. We found that expression of adequate ER is strong associated with the ability of human breast cancer cell growth inhibition and progression. Compared with nontransfected or mock-transfected cells, ER-transfected cells exhibited growth slower, forming smaller colonies in soft agar and growth inhibited by estrogen and tamoxifen. Therefore reactivation or transfection of the estrogen receptor gene can be considered as therapeutic approaches to hormone-independent breast cancer.

Breast Neoplasms↗

PubMed1997

[A monoclonal antibody directed against an enediyne antitumor antibiotic and its preliminary application].

C1027, composed of an enediyne chromophore and an apoprotein of 110 amino acid residues, is a new highly potent macromolecular antitumor antibiotic. In order to prepare monoclonal antibodies (McAb) against C1027 by hybridoma technique, natural C1027 was inactivated by ultraviolet and coupled with human serum albumin, then immunized BALB/c mice. After cell fusion and screening by ELISA, a hybridoma secreting anti-C1027 McAb designated as F9 was obtained. McAb F9 specifically reacted with C1027 as determined by immunoblot assay. No obvious difference was observed between the reactivity of McAb F9 to natural C1027 and that of McAb F9 to ultraviolet inactivated C1027. This result indicates that the ultraviolet-sensitive chromophore of C1027 may not participate in the epitope for McAb F9. The isotype of F9 is IgG1 and its affinity constant was found to be (2.2 +/- 0.47) x 10(7) L.mol-1 according to Beatty's method. By clonogenic assay, McAb F9 neither affected the cytotoxicity of C1027 to KB cells nor blocked the activity of the chromophore. McAb F9 also specifically reacted with the recombinant truncated C1027 apoprotein in which 16 amino acid residues at the C terminus were deleted. This study suggests that F9 is a valuable McAb for the research of C1027 apoprotein engineering, C1027 related immunoconjugates and screening of new macromolecular antitumor substances with homology to the protein part of C1027.

Aminoglycosides↗

PubMed1997

p53 independent G1 arrest and apoptosis induced by adriamycin.

The biological activity of adriamycin was investigated in human breast carcinoma (HBC) cells, Adriamycin inhibited the growth of a number of HBC cell lines and induced G1 arrest followed by apoptosis. In MCF-7 cells that harbor wild-type p53, adriamycin-induced G1 arrest and apoptosis was accompanied by p53-independent regulation of WAF1/CIP1 as well as bax mRNA levels. In MDA-MB-231 cells which possess a mutant p53, adriamycin-induced G1 arrest and apoptosis was also associated with a concomitant up-regulation of WAF1/CIP1 mRNA while these cells did not express bax or bcl-2 messages. Thus, adriamycin induces G1 arrest and apoptosis via a unique pathway which appears to involve activation of downstream effectors of p53-independent manner.

Antineoplastic Agents↗

PubMed1997

[Rapid determination of aspartame in compound sweetening by reversed-phase high performance liquid chromatography].

A method for rapid determination of Aspartame in compound sweetening by reversed-phase high performance liquid chromatography is presented. Aspartame in compound sweetening was separated in a short column (Ultrasphere XL-ODS, 3 microm, 4.6 mm x 70 mm) by using CH3OH-0.02 mol/L NH4Ac as mobile phase. The flow rate was 0.8 mL/min. Detection was performed with UV detector at 220 nm. The injection volume was 20 microL. It was qualitatively analysed by UV scanning at a wavelength range of 200-350 nm under no-stop flow according to their retention time. Quantitative analysis was carried out by measuring peak height and comparing it with external standard. The minimum detectable amount was 5 microg/L. The linear range of the calibration curve was 40-200 mg/L. The average recovery of Aspartame was 92%. The relative standard deviation was 2.9%. This method is simple, rapid and sensitive.

Aspartame↗

PubMed1997

[Liquid chromatographic separation of pepsinogens].

In this work, we reported a method for the purification of pepsinogens from human gastric mucosa with high pressure gel filtration chromatography (HPLC) and medium pressure anion exchange chromatography (MPLC). First, the two fractions of Pg1 and mixture of PGI and PGII were separated from pepsinogens with HPLC on a Bio-Sil SEC-125 column within 50min. Then the mixture of fractions of PGI and PGII was further separated with MPLC on a Bio-Scale Q2 column within 30min.

Chromatography, High Pressure Liquid↗

PubMed1997

[An analysis of maicaodi by high performance liquid chromatography].

Maicaodi has recently been developed and produced by the pesticide plant of Nanjing Agricultural University. The quantitative analysis of the effective components--tribenuron methyl and R (-)napropamide in wettable powder of Maicaode, by a high performance liquid chromatographic method was carried out with a Lichrosorb Si-60 20cm x 0.46cm i.d. column, mobile phase of petroleum ether/isopropanol/methanol/acetonitrile/chloroform mixture solvent (80:5:5:5:5) and internal standard of diisooctyl phthalate. The sample was detected by ultraviolet absorption at 254 nm. The retention times of tribenuron methyl and R (-)napropamide were 10-11min and 6-7min respectively. The coefficient of variation of this analysis was 0.34% with a recovery of 99.51%-100.32%. The coefficient of linear correlation was 0.9999.

Chromatography, High Pressure Liquid↗

PubMed1997

Inactivation of the G alpha i2 and G alpha o genes by homologous recombination.

G proteins couple receptors to effectors and thus regulate multiple biological processes. Here we report on the phenotypes of G alpha i2-deficient and G alpha o-deficient mice. G alpha i2-deficient mice display a blunted inhibitory regulation of adenylyl cyclase, alterations in T cell maturation and function, a growth retardation and also develop a lethal diffuse colitis with clinical and histopathological features closely resembling ulcerative colitis in humans, including the development of adenocarcinoma of the colon. G alpha o-deficient mice are also viable, but significantly smaller than wild-type controls.

Animals↗

PubMed1997

Observation of developing cercaria of Schistosoma japonicum on ultrastructural level and remarks at its morphology of mature stage.

OBJECTIVE: To study the developing cercaria of Schistosoma Japonicum (S. japonicum) on ultrastructural level by transmission electron microscope (TEM) for analyzing the morphological dynamic changes of the tegument, glands and musculature. METHODS: Artificial infected Oncomelania hupensis were dissected under dissecting microscope and the daughter sporocysts picked up for studying the germinal cells stage (S1). The other embryonic cercaria were selected according to the modified parameter of Chen and Bier (1972). The specimens were prepared by conventional procedure of the laboratory of TEM and were observed by Hitachi H600. RESULTS: Beside the germinal cell stage (S1), this is the first chronological study on the morphological development of S. japonicum cercaria from S2-S5 concerning the tegument and its elements (glycocalyx, sensory papilla, basal lamina and spine), head and acetabular gland and musculature of the body and tail. This article discusses the ultrastructural morphological differences from prior authors and emphasizes on the postacetalar gland and the pattern of tail musculature of the matured stage cercaria. CONCLUSIONS: According to the cell division and differentiation, the process of development may be divided into 5 stages: S1, the single germinal cell stage; S2, the germinal ball stages: major multiplication and minor differentiation; S3, tail budding embryonic stage, both active in multiplying and differentiating; S4, the pre-matured stage, major differentiation and minor multiplication; and S5, the fully matured stage (completing the differentiation).

Animals↗

PubMed1996

On the molecular basis and regulation of cellular capacitative calcium entry: roles for Trp proteins.

During the last 2 years, our laboratory has worked on the elucidation of the molecular basis of capacitative calcium entry (CCE) into cells. Specifically, we tested the hypothesis that CCE channels are formed of subunits encoded in genes related to the Drosophila trp gene. The first step in this pursuit was to search for mammalian trp genes. We found not one but six mammalian genes and cloned several of their cDNAs, some in their full length. As assayed in mammalian cells, overexpression of some mammalian Trps increases CCE, while expression of partial trp cDNAs in antisense orientation can interfere with endogenous CCE. These findings provided a firm connection between CCE and mammalian Trps. This article reviews the known forms of CCE and highlights unanswered questions in our understanding of intracellular Ca2+ homeostasis and the physiological roles of CCE.

Animals↗

PubMed1996

Activation of locus coeruleus enhances the responses of olfactory bulb mitral cells to weak olfactory nerve input.

The main olfactory bulb (MOB) receives a dense projection from the pontine nucleus locus coeruleus (LC), the largest collection of norepinephrine (NE)-containing cells in the brain. LC is the sole source of NE innervation of MOB. Previous studies of the actions of exogenously applied NE on mitral cells, the principal output neurons of MOB, are contradictory. The effect of synaptically released NE on mitral cell activity is not known, nor is the influence of NE on responses of mitral cells to olfactory nerve inputs. The goal of the present study was to assess the influence of LC activation on spontaneous and olfactory nerve-evoked activity of mitral cells. In methoxyflurane-anesthetized rats, intracoerulear microinfusions of acetyicholine (ACh) (200 mM; 90-120 nl) evoked a four- to fivefold increase in LC neuronal discharge, and a transient EEG desynchronization and decrease in mitral cell discharge. LC activation increased excitatory responses of mitral cells evoked by weak (i.e., perithreshold) nasal epithelium shocks (1.0 Hz) in 17/18 cells (mean Increase = 67%). The discharge rate of mitral cells at the time that epithelium-evoked responses were increased did not differ significantly from pre-LC activation baseline values. Thus, changes in mitral baseline activity do not account for the increased response to epithelium stimulation. These findings suggest that increased activity in LC-NE projections to MOB may enhance detection of relatively weak odors.

Acetylcholine↗

PubMed1996

trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry.

SUMMARY: Capacitative calcium entry (CCE) describes CA2+ influx into cells that replenishes CA2+ stores emptied through the action of IP3 and other agents. It is an essential component of cellular responses to many hormones and growth factors. The molecular basis of this form of Ca2+ entry is complex and may involve more than one type of channel. Studies on visual signal transduction in Drosophila led to the hypothesis that a protein encoded in trp may be a component of CCE channels. We reported the existence of six trp-related genes in the mouse genome. Expression in L cells of small portions of these genes in antisense orientation suppressed CCE. Expression in COS cells of two full-length cDNAs encoding human trp homologs, Htrp1 and Htrp3, increased CCE. This identifies mammalian gene products that participate in CCE. We propose that trp homologs are subunits of CCE channels, not unlike those of classical voltage-gated ion channels.

Amino Acid Sequence↗