Biomedical subjects

H Peng

Publications and source records attributed to H Peng.

At least 37 records · Page 2Linked to original sources

PubMed2001

Development of a thickness shear mode acoustic sensor based on an electrosynthesized molecularly imprinted polymer using an underivatized amino acid as the template.

The preparation and characterization of electrosynthesized poly(o-phenylenediamine) (iPoPD) as a molecular imprinting material were studied by an in situ quartz crystal impedance method. The changes of delta f0, delta R1, delta L1 and delta C0 suggest that the polymer film was compact and rigid. The thickness shear mode (TSM) acoustic sensor modified with this material exhibits molecular recognition ability to the template molecule of DL-phenylalanine. In the range 2-20 mM, a linear relationship between the frequency shift delta f0 and logC was found from the calibration graph. Scatchard analysis of the relevant calibration graph offers information on the equilibrium of the binding interaction and the recognition sites. Using this electropolymerization technology, the preparation of the sensor was very simple and the reproducibility of preparation was very good. In particular, it offers possibilities for sensor miniaturization.

Journal Article↗

PubMed2001

Effect of indomethacin on peritoneal protein loss in a rabbit model of peritonitis.

BACKGROUND: Although various inflammatory mediators have been previously shown to be released into the peritoneal cavity during peritonitis in peritoneal dialysis patients, those that are involved in governing changes in peritoneal permeability to small solutes and protein remain incompletely defined. METHODS: We determined the importance of prostanoid production in the enhanced protein loss observed during acute peritonitis by inhibition experiments using indomethacin, an inhibitor of cyclooxygenase activity. The association between changes in peritoneal permeability and the generation of inflammatory mediators after adding Escherichia coli to peritoneal dialysate was first examined in series 1 experiments. Series 2 experiments then determined the effect of intraperitoneal administration of indomethacin (75 microg/mL) on changes in peritoneal permeability after adding E. coli to peritoneal dialysate. All experiments were performed in male New Zealand White rabbits (2.6 to 3.4 kg body weight) using an eight-hour dwell of dialysate containing 2.5% glucose. Peritoneal permeability to creatinine and protein was assessed by time-dependent changes in the dialysate to plasma concentration ratios of these solutes. RESULTS: Series 1 experiments showed enhanced leukocyte migration into the peritoneal cavity and increased peritoneal permeability to protein during bacterial challenge that was accompanied by an increase in the dialysate concentrations of prostaglandin E2 (PGE2), 6-keto-PGF1alpha, and interleukin-8, but not nitrate + nitrite (a measure of local nitric oxide production). Inhibition of prostanoid production by intraperitoneal administration of indomethacin in series 2 experiments resulted in lower dialysate concentrations of PGE2 and 6-keto-PGF1alpha and in lower peritoneal permeability to protein, both to control levels. No effect of indomethacin on transperitoneal migration of leukocytes or the generation of interleukin-8 was observed. CONCLUSIONS: Enhanced production of prostanoids likely plays an important role in governing the increase in peritoneal permeability to protein during acute, bacterial peritonitis in the rabbit.

6-Ketoprostaglandin F1 alpha↗

PubMed2001

Novel nuclear signaling pathway mediates activation of fibroblast growth factor-2 gene by type 1 and type 2 angiotensin II receptors.

In bovine adrenal medullary cells synergistically acting type 1 and type 2 angiotensin II (AII) receptors activate the fibroblast growth factor-2 (FGF-2) gene through a unique AII-responsive promoter element. Both the type 1 and type 2 AII receptors and the downstream cyclic adenosine 1',3'-monophosphate- and protein kinase C-dependent signaling pathways activate the FGF-2 promoter through a novel signal-transducing mechanism. This mechanism, which we have named integrative nuclear FGF receptor-1 signaling, involves the nuclear translocation of FGF receptor-1 and its subsequent transactivation of the AII-responsive element in the FGF-2 promoter.

Adrenal Medulla↗

PubMed2001

Antifibrotic effects of N-acetyl-seryl-aspartyl-Lysyl-proline on the heart and kidney in aldosterone-salt hypertensive rats.

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) inhibits not only hematopoietic cell proliferation but also fibroblast proliferation and collagen synthesis in vitro. Ac-SDKP also prevents collagen deposition and cell proliferation in the left ventricle (LV) in rats with renovascular hypertension (renin dependent). However, it is not clear whether Ac-SDKP has similar effects in a model of renin-independent hypertension (aldosterone-salt). Using a hypertensive rat model of cardiac and renal fibrosis created by chronic elevation of circulating aldosterone (ALDO) levels, we examined the effect of Ac-SDKP on blood pressure, cardiac and renal fibrosis and hypertrophy, and proliferating cell nuclear antigen (PCNA) expression in the LV and left kidney. Uninephrectomized rats were divided into 4 groups: (1) controls that received tap water, (2) rats that received ALDO (0.75 microgram/h SC) and 1% NaCl/0.2% KCl in drinking water (ALDO-salt), (3) rats that received ALDO-salt plus Ac-SDKP 400 microgram. kg(-1). day(-1) SC, and (4) rats that received ALDO-salt plus Ac-SDKP 800 microgram. kg(-1). d(-1) SC. After 6 weeks of treatment, the ALDO-salt group was found to have significantly increased blood pressure with decreased body weight and plasma renin concentration (P<0.05), LV and renal hypertrophy as well as renal injury, significantly increased collagen content in both ventricles and kidney as well as increased collagen volume fraction in the LV (P<0.0001), and significantly increased interstitial and perivascular PCNA-positive cells in the LV and kidney (P<0.0001). Ac-SDKP at 800 microgram. kg(-1). d(-1) markedly prevented cardiac and renal fibrosis (P<0.005) without affecting blood pressure or organ hypertrophy. It also suppressed PCNA expression in the LV and kidney in a dose-dependent manner. We concluded that Ac-SDKP prevents increased collagen deposition and cell proliferation in the heart and kidney in ALDO-salt hypertensive rats. Because ACE inhibitors increase plasma and tissue Ac-SDKP and decrease cardiac and renal fibrosis, we speculate that Ac-SDKP may participate in the antifibrotic effect of ACE inhibitors.

Aldosterone↗

PubMed2001

Effect of N-acetyl-seryl-aspartyl-lysyl-proline on DNA and collagen synthesis in rat cardiac fibroblasts.

N:-Acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a natural inhibitor of pluripotent hematopoietic stem cell entry into the S phase of the cell cycle and is normally present in human plasma. Ac-SDKP is exclusively hydrolyzed by ACE, and its plasma concentration is increased 5-fold after ACE inhibition in humans. We examined the effect of 0.05 to 100 nmol/L Ac-SDKP on 24-hour (3)H-thymidine incorporation (DNA synthesis) by cardiac fibroblasts both in the absence and presence of 5% FCS. Captopril (1 micromol/L) was added in all cases to prevent the degradation of Ac-SDKP. Treatment of cardiac fibroblasts with 5% FCS increased thymidine incorporation from a control value of 12 469+/-594 to 24 598+/-1051 cpm (P:<0.001). Cotreatment with 1 nmol/L Ac-SDKP reduced stimulation to control levels (10 373+/-200 cpm, P:<0.001). We measured hydroxyproline content and incorporation of (3)H-proline into collagenous fibroblast proteins and found that Ac-SDKP blocked endothelin-1 (10(-8) mol/L)-induced collagen synthesis in a biphasic and dose-dependent manner, causing inhibition at low doses, whereas high doses had little or no effect. It also blunted the activity of p44/p42 mitogen-activated protein kinase in a biphasic and dose-dependent manner in serum-stimulated fibroblasts, suggesting that the inhibitory effect of DNA and collagen synthesis may depend in part on blocking mitogen-activated protein kinase activity. Participation of p44/p42 in collagen synthesis was confirmed, because a specific inhibitor for p44/p42 activation (PD 98059, 25 micromol/L) was able to block endothelin-1-induced collagen synthesis, similar to the effect of Ac-SDKP. The fact that Ac-SDKP inhibits DNA and collagen synthesis in cardiac fibroblasts suggests that it may be an important endogenous regulator of fibroblast proliferation and collagen synthesis in the heart. Ac-SDKP may participate in the cardioprotective effect of ACE inhibitors by limiting fibroblast proliferation (and hence collagen production), and therefore it would reduce fibrosis in patients with hypertension.

Angiotensin II↗

PubMed2001

Effects of angiotensin-converting enzyme inhibitor and angiotensin type 1 receptor antagonist in deoxycorticosterone acetate-salt hypertensive mice lacking Ren-2 gene.

We previously reported that inhibition of angiotensin-converting enzyme (ACE) prevented the hypertension and left ventricular hypertrophy induced by deoxycorticosterone acetate-salt (DOCA-salt) in 129/SvEvTac mice, which have 2 renin genes (Ren-1 and Ren-2). In the present study, we induced hypertension by uninephrectomy and DOCA-salt in mice having only the Ren-1 gene (C57BL/6J) and investigated the effect of an ACE inhibitor (ramipril, 4 mg. kg(-)(1). d(-)(1)) and an angiotensin type 1 (AT(1)) receptor antagonist (L-158809, 4 mg. kg(-)(1). d(-)(1)) on the development of hypertension, cardiac hypertrophy, and renal injury. After 4 weeks of treatment, systolic blood pressure in DOCA-salt mice was significantly increased (128+/-2 mm Hg) compared with controls (109+/-2 mm Hg) (P:<0.001), while plasma renin concentration was decreased by 97% (P:<0.001). DOCA-salt also induced left ventricular and renal hypertrophy and renal damage as manifested by proteinuria. Collagen content in the left ventricle and kidney was significantly higher in DOCA-salt mice (P:<0.001). Urinary albumin (P:<0.05) and proliferating cell nucleic antigen-positive cells in the tubules and interstitium of the renal cortex (P:<0.001) were significantly increased in the DOCA-salt group. Neither the ACE inhibitor nor the AT(1) antagonist had any antihypertensive effect; however, they partially prevented cardiac hypertrophy and completely inhibited left ventricular collagen deposition. In the kidney, both the ACE inhibitor and AT(1) antagonist partially reduced the increase in collagen but had no effect on hypertrophy. They also significantly prevented the effect of DOCA-salt on urinary albumin and proliferating cell nucleic antigen expression in the kidney. Despite the lack of an antihypertensive effect, both ACE inhibitor and AT(1) antagonist prevented cardiac remodeling and renal damage. Our results indicate that ACE inhibitors and AT(1) antagonists exert beneficial effects on the heart and kidney in DOCA-salt hypertensive mice independently of their effects on blood pressure.

Angiotensin Receptor Antagonists↗

PubMed2001

Potential for mating disruption of Sparganothis sulfureana (Lepidoptera: Tortricidae) in cranberries.

The feasibility of disrupting mating of Sparganothis fruitworm with a sprayable microencapsulated formulation of (E)-11-tetradecenyl acetate (E11-14:Ac), the major pheromone component, was evaluated in New Jersey during 1996 and 1997 seasons. In both years, application of encapsulated E11-14:Ac, at 25-187.5 g (AI)/ha, reduced the incidence of mating of virgin females placed in treated plots relative to those placed in control plots. Pheromone trap catches were lower in pheromone treated plots, indicating that fewer male moths were able to locate the traps in treated plots. Larval density and fruit damage were significantly lower in plots treated with 62.5,125, or 187.5 g (AI)/ha of pheromone than in the untreated control. Air and foliage samples were collected to determine the air titers and foliage residuals of E11-14:Ac throughout the adult flight during 1996 and 1997. E11-14:Ac levels in air and foliage samples, declined sharply one wk after the pheromone application. However, detectable levels of E11-14:Ac were present in both air and foliage samples throughout the 3- to 4-wk period after the pheromone application. Multiple applications of pheromone at lower rates may be more effective in maintaining pheromone levels than a single dose at higher rates. These results suggest that mating disruption is a promising strategy to manage Sparganothis fruitworm in cranberries.

Animals↗

PubMed2001

Career group counseling in undecided college female seniors' state anxiety and career indecision.

A sample of female college seniors experiencing career indecision participated in a career group counseling (n: 16), a wait-list control group (n: 8), and an additional career-counseling group (n: 11). Participants were administered the Career Decision Scale and the State-Trait Anxiety Inventory at pretest and posttest. Analysis of covariance of state anxiety scores and career indecision scores yielded significant main effects for treatment. Participants in the career-counseling groups showed a decrease in scores on state anxiety and career indecision. Implications for research and female career group counseling are also discussed.

Adult↗

PubMed2001

[Genotypes of transfusion-transmitted virus].

OBJECTIVE: To investigate the genotypes of transfusion-transmitted virus (TTV) in South China. METHODS: One capture probe for all types of TTV from the conserved sequence nt2160 to nt2196 and six varied probes, heterogeneity more than 20% between each other for G1, G2, G3, G4, G5 and G6 type, respectively were synthesized. The primers coming from the conserved sequence of ORF1 were used to amplify TTV DNA from the serums of patients. Microplate sandwich hybridization-ELISA technique was used to detect the genotypes of TTV in 380 hepatitis patients with liver damage. RESULTS: Sixty-one of 380 patients, about 16.0%, were TTV DNA positive, in whom 44 were genotype I (G1), 5 were G2, 10 were mixed infection of G1 and G2, one was G3 and one was G4. Neither G5 nor G6 has been detected. The rate of TTV infection in chronic hepatitis patients was equal to that in acute hepatitis patients. CONCLUSIONS: TTV infection is common in South China. There are four types of TTV. The first genotype was G1, and the second was G2. G5 or G6 has not yet been detected. PCR microplate sandwich hybridization-ELISA has certain value in clinic diagnosis for its specific, sensitive and practicable characters.

DNA Virus Infections↗

PubMed2001

[Effect of photoperiod and temperature on fertility alteration of short photoperiod-low temperature induced male sterile rice].

Short photoperiod-low temperature induced male sterile rice is a new germplasm, whose fertility alteration characteristic is contrary to that of long photoperiod and high temperature induced male sterile rice. Compared with that of Yid1s sowed under natural conditions by stages, the fertility alteration of Yid1s was observed under simulated short photoperiod treatment. The results showed that the photoperiod-sensitive stage of Yid1s occurred from differentiation of rachis primordia (phase I) to secondary rachis-branch and spikelet primordia (phase III). The panicles induced by appropriate short daylight treatment at photoperiod-sensitive stage tended to be completely sterile under normal temperature, but the sterile effect was weakened under high temperature. The pollen fertility of Yid1s was reduced under high or low temperature. The temperature-sensitive stages of Yid1s based on the analysis of the effects of high and low temperature on fertility were basically identical, i.e., from pollen mother cell formation (phase V) to single nucleus (phase VII).

Fertility↗

PubMed2001

[Geographic distribution and feature of Yersinia pestis plasmid isolated from Yunnan province].

OBJECTIVE: To analysis the molecular-epidemiological feature of Yersinia pestis plasmid isolated from Yunnan. METHODS: One thousand and twenty strains of Y. pestis isolates from 44 counties of Yunnan province in China and the border of China-Myanmar using Kado and Liu method and detected by agrose gel electrophoresis. RESULTS: Results showed that these strains from Yunnan province carried 9 kinds of plasmids with molecular weights about 3.93, 6.05, 22.97, 35.65, 45.35, 64.82, 74.59, 111.36 and 129.55 x 10(6). Of these, three kinds of 3.93, 35.65 and 111.36 x 10(6) were found very specific, only reported in Yunnan. The plasmid profile could be divided into 10 types according to the plasmid content. Type I-V were common and had a clustering nature in geographic distribution. CONCLUSION: Based on the plasmid profile, the epidemic districts of plague could be divided into several independent plague foci, suggesting that the resurgence of domestic rat caused plague epidemics might have several hidden plague foci as the result of epidemics since 1982 in Yunnan.

Animals↗

PubMed2001

[Alveolar macrophage and airway inflammation in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the effects of alveolar macrophage(AM) on airway inflammation of chronic obstructive pulmonary disease(COPD). METHODS: Broncho alveolar fluid(BALF) and bronchial mucosa biopsies were performed as usual. The levels of macrophage inflammatory-1 alpha (MIP-1 alpha), gelatinase B (MMP-9), interleukin(IL)-8 in BALF and the culture supernatants of AMs were measured with ELISA. The levels of endothelin (ET) were measured with radioimmunoassay method. The AMs expressing lymphocytic functional associated antigen-1 (LFA-1) in BALF, the AMs in mucosa and the thickness of mucosa were measured with immunocytochemistry and immunohistochemistry technique. RESULTS: The levels of MIP-1 alpha, MMP-9, IL-8 and ET in the culture supernatants of AMs in patients with COPD were (1 446.9 +/- 126.7) microg/L, (16.98 +/- 5.15) microg /L, (43.98 +/- 5.54) ng/L, (168.10 +/- 21.22) microg/L respectively; while those were (1 123.5 +/- 90.6) microg/L, (5.24 +/- 0.93) microg/L, (25.99 +/- 6.05) ng/L, (124.68 +/- 9.96) microg/L in a control group. The number of macrophages in mucosa in patients with COPD was (1.71 +/- 0.48) cells/Hp, while that was (0.59 +/- 0.18) cells/Hp in the control group (0.63 +/- 0.25) x 10(4). Statistical significance was found between the two groups. The number of AMs and polymorphonuclear leucocyte in BALF were inversely correlated with forced expiratory volume in one second as percentage of predicted value(FEV(1)% Pre) (r = -0.511, P < 0.01; r = -0.562, P < 0.01). The levels of MMP-9 and ET in the culture supernatants of AMs were inversely correlated with FEV(1)% Pre(r = -0.678, P < 0.01; r = -0.871, P < 0.01). Both the level of MIP-1 alpha and the positive number of AM expressing LFA-1 in BALF were positively correlated with the number of AMs in BALF(r = 0.572, P < 0.01; r = 0.625, P < 0.01). CONCLUSION: AM may be involved in the process of airway inflammation and subsequent airway obstruction.

Adult↗

PubMed2001

[The change of concentration of endothelin derived from alveolar macrophages and in induced sputum in patients with chronic bronchitis].

OBJECTIVE: To evaluate the changes of levels of endothelin (ET) in induced sputum, the culture supernatants of alveolar macrophages (AMs) and the culture supernatants of alveolar macrophages (AMs) when cultivated with aminophylline and lipopolysaccharide (LPS) in patients with chronic bronchitis and COPD. Then to investigate the role of ET derived from AMs in chronic bronchitis and COPD. METHODS: Fourteen patients with chronic bronchitis and thirteen patients with COPD were studied. Fourteen healthy were enrolled as control. Bronchoscopy and bronchial alveolar lavage were performed routinely, BAL cells were count with hemacytometer and differentater with wright stain. Sputum induction with 4% saline was performed on twenty-six subjects. The levels of ET in BALF and in the culture supernatants of AMs were measured by radioimmunoassay methods. RESULTS: (1) The number of all cells, neutrophils and AMs in BALF of patients with chronic bronchitis and COPD were significantly higher than those of healthy control group (P < 0.01 respectively). (2) The levels of ET in the culture supernatants of AMs and induced sputum were higher in heathy than those in patients with chronic bronchitis and COPD (P < 0.01 respectively). But there were no differences between patients with chronic bronchitis and COPD (P > 0.05 respectively). (3) Positive correlation was found between the levels of ET in the culture supernatants of AMs and those in induced sputum (r = 0.741, P < 0.01), between the number of AMs and the levels of ET in induced sputum (r = 0.597, P < 0.01). (4) Negative correlation was found between FEV(1)% of predicted value and the levels of ET in the culture supernatants of AMs in patients with COPD (r = -0.828, P < 0.01), between FEV(1)% of predited value and the levels of ET in induced sputum in patients with COPD (r = -0.748, P < 0.05). (5) In the culture with aminophylline, the level of ET derived from AMs remained stable (P > 0.05). But in the culture with LPS, the level of ET was significantly higher than that in the culture with DMEM (P < 0.01). CONCLUSIONS: (1) The characteristics of non-specific airway inflammation in patients with chronic bronchitis and COPD is the increased numbers of neutrophils and AMs. (2) AMs are perhaps important sources of ET in the lung. LPS can stimulate AMs to secrete more ET. ET derived from AMs takes part in development of COPD.

Adult↗

PubMed2001

[Sewage treatment by the canal reactor with biomembrane].

This paper studies that utilizing sewage canal (waterway) of city to treat sewage on bases of researching water pollution, hydrological data and topography of the canal. A new canal reactor of bacteria membrane with continuous operation was designed, made and studied in the laboratory. The operation results of the reactor show that the reactor could effectively treat the sewage of city. The average data of continuous operation during 3 months showed that the removal ratios of CODCr and BOD5 were 88% and 95% in the range of CODCr concentration 180 mg.L(-1)-450 mg.L-1 in the inlet, separately. The technology also has the advantage of low capital cost, low operation cost. This will create the condition to apply the way to practical living sewage treatment of canal.

Bacteria↗

PubMed2001

[The mutation of anti-CD3 antibody (HIT3a) gene and its expression].

OBJECTIVE: To improve the expression of anti-CD(3) single chain Fv (scFv) by site mutation and identify its biological activity. METHODS: Anti-CD(3) scFv gene was mutated by PCR, the target clones were screened by both the fingerprints of DNA restriction endonuclease digestion and Western blot, the antigen-binding activity of scFv was examined by FACS, competitive inhibition was performed with (125)I-labeled HIT3a and the cytotoxic effect mediated by the anti-CD(3) scFv-activated T lymphocytes was analyzed by (51)Cr-released assays. RESULTS: The DNA sequencing showed that the 6th amino acid of the anti-CD(3) antibody (HIT3a) heavy chain gene was mutated from E (GAG) to Q (CAG). The expression of mutated anti-CD(3) scFv (m2) was increased by 100 times higher than that of the parent scFv, and there was no difference in the Jurkat cell (CD(3)(+))-binding activity between the (m2) and parent scFv. The preliminary results of competitive assays showed that m2 could partially block the sites of CD(3)(+) Jurkat cells where the parent antibody bound to. Cytotoxicity assays demonstrated that CD(3)AK cells induced by IL-2 and m2 showed stronger cytotoxic effect than that of LAK cells induced by IL-2 alone in vitro. CONCLUSION: By site mutation, a high expression fragment m2 of anti-CD(3) scFv antibody was obtained. The results of some experiments indicated that m2 could bind to CD(3)(+) Jurkat cells, furthermore, by co-stimulated with IL-2, it could activate peripheral T lymphocytes and induce CD(3)AK cytotoxic effect.

CD3 Complex↗

PubMed2001

[Study of specific targeting cytotoxicity mediated by anti-CD(3)/anti-CD(20) Diabody].

OBJECTIVE: To study the specific targeting cytotoxicity mediated by an anti-CD(3)/anti-CD(20) diabody. METHODS: The diabody was purified by affinity chromatography and identified by Western blot assay, size exclusion chromatography, FACS and rosetting assay; the effect of the anti-CD(3)/anti-CD(20) diabody mediated lysis of CD(20)-expressing tumor cells was assayed by (51)Cr release assay in vitro and by human B cell tumor nude mice xenograft model in vivo. RESULTS: The anti-CD(3)/anti-CD(20) diabody could bind both Jurkat cells (CD(3)(+)) and Daudi cells (CD(20)(+)) and appeared to be potent in targeting activated peripheral blood mononuclear cell (PBMC) to lyse Daudi cells in vitro. Furthermore, it inhibited tumor growth and prolonged the survival of mice bearing xenografted Raji cells. CONCLUSION: The diabody proved to be a potent agent for targeting peripheral blood lymphocytes to lyse CD(20) antigen expressing tumor cells in vitro and in vivo.

Animals↗

PubMed2000

Assessment of methods for tissue-based detection of the HER-2/neu alteration in human breast cancer: a direct comparison of fluorescence in situ hybridization and immunohistochemistry.

PURPOSE: To compare the efficacy of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in detecting the HER-2/neu alteration in human breast cancer. PATIENTS AND METHODS: Unselected stage I, II, and III breast cancer patients (N = 900) were tested for HER-2/neu gene amplification by FISH in paraffin-embedded, formalin-fixed archival material. Of these samples, 856 were tested for HER-2/neu overexpression by non-antigen-retrieval IHC with the polyclonal antibody R60, the sensitivity and specificity of which was preliminarily compared with the United States Food and Drug Administration-approved HercepTest (Dako Corp, Carpinteria, CA). Patient survival was analyzed in relation to the presence of the HER-2/neu alteration as determined by these two methodologies. RESULTS: A total of 189 (21%) of 900 patients were positive by FISH and 147 (17.2%) of 856 were positive by IHC. This discrepancy is consistent with expected loss of IHC sensitivity associated with tissue fixation/embedding. The HercepTest did not improve sensitivity and introduced false positives. Comparison of R60-based IHC with FISH demonstrates that patient survival is associated progressively to gene amplification level as determined by FISH, whereas for IHC an association is found only in the highest (3+) immunostaining group. Among FISH-negative tumors, 45 (6.6%) of 678 were IHC-positive, with a survival probability similar to that of FISH-negative/IHC-negative cases; FISH-positive/IHC-negative patients have a survival probability similar to that of FISH-positive/IHC-positive cases. CONCLUSION: IHC does not consistently discriminate patients likely to have a poor prognosis, whereas FISH provides superior prognostic information in segregating high-risk from lower-risk beast cancers. HER-2/neu protein overexpression in the absence of gene amplification occurs infrequently in breast cancer, in which case, patient outcome is similar to that of patients without the alteration.

Adult↗

PubMed2000

Cyclic nucleotide regulation of Na+/glucose cotransporter (SGLT1) mRNA stability. Interaction of a nucleocytoplasmic protein with a regulatory domain in the 3'-untranslated region critical for stabilization.

Expression of the Na(+)-coupled glucose cotransporter SGLT1 is regulated post-transcriptionally at the level of mRNA stability. We have previously demonstrated that cAMP-dependent stabilization of the SGLT1 message was correlated with the protein phosphorylation-dependent binding of cytoplasmic proteins to a uridine-rich sequence (URE) in the 3'-untranslated region (UTR). In the present study, the regulatory role of the URE was demonstrated by inserting it into the 3'-UTR of a beta-globin reporter minigene under the control of the tetracycline-regulated promoter. The resultant chimeric globin/SGLT1 mRNA expressed after transfection into LLC-PK1 cells exhibited a decreased half-life compared with the beta-globin control, indicating that the URE serves a destabilizing function. Activation of protein kinase A stabilized the chimeric message but not the beta-globin control, indicating the presence of a regulatory stabilizing sequence within the URE. A 38-kDa nucleocytoplasmic protein was identified that recognized a 12-nucleotide binding site within the URE. A mutation in this binding site that prevented protein binding assayed in vitro by UV cross-linking also prevented protein kinase A-dependent stabilization of the chimeric message assayed in vivo. These findings identify the interaction between a 38-kDa nucleocytoplasmic protein and a regulatory uridine-rich sequence in the 3'-UTR as critical for cAMP-mediated SGLT1 message stabilization.

1-Methyl-3-isobutylxanthine↗