Carboxyfluorescein as a marker at both light and electron microscope levels to follow cell lineage in the embryo.
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Animals↗
Biomedical subjects
D Sun
Publications and source records attributed to D Sun.
Cloning and expression of murine sister of P-glycoprotein reveals a more discriminating transporter than MDR1/P-glycoprotein.
Sister of P-glycoprotein (SPGP), a novel murine cDNA and member of the ATP-binding cassette superfamily highly homologous to P-glycoprotein (Pgp), was cloned. Moreover, its genomic clone was isolated and localized to chromosome 2 by fluorescence in situ hybridization. SPGP was functionally evaluated relative to MDR1 after subcloning SPGP cDNA into a retroviral bicistronic vector capable of expressing both SPGP and the green fluorescent protein. LLC-PK1 and MDCKII cells were transduced with this retrovirus and SPGP-positive clones were isolated. Drug uptake and efflux was compared in cells ectopically expressing either SPGP or human MDR1. SPGP cells had decreased uptake of taurocholate and vinblastine compared with LLC-PK1 cells. Additional studies revealed that vinblastine efflux was accelerated by SPGP compared with LLC-PK1. Further comparison revealed that although MDR1 easily impaired uptake of vincristine, daunomycin, paclitaxel, and digoxin, SPGP had no effect on uptake of these drugs. However, further studies demonstrated that, like MDR1, SPGP effluxed calcein-acetoxymethyl ester (AM). Unlike MDR1, SPGP was incapable of effluxing rhodamine 123. Although cyclosporine A and reserpine blocked calcein-AM transport by MDR1, these drugs had either minimal or no effect, respectively, on blocking SPGP efflux of calcein-AM. In contrast, ditekiren, a linear hexapeptide, readily and preferentially inhibited SPGP efflux of calcein-AM. Further studies with three structural analogs of ditekiren revealed that one analog inhibited SPGP efflux of calcein-AM, although not as potently as ditekiren. These are the first studies to reveal that SPGP has distinct transport properties compared with MDR1.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Clinical application of 201Tl SPECT imaging of brain tumors.
UNLABELLED: This study investigated the clinical usefulness of evaluating the histologic grade of brain tumors by 201Tl SPECT brain imaging. METHODS: Early and delayed SPECT brain images were obtained about 10 min and 3 h, respectively, after intravenous injection of 111MBq (3 mCi) 201Tl in 9 healthy subjects (control subjects), 3 patients with brain hematomas, and 41 patients with brain tumors. Semiquantitative data were obtained for early and delayed 201Tl uptake indices and 201Tl retained index in all patients and healthy subjects. RESULTS: In 9 healthy subjects, there was little radioactivity in brain substance. In all patients with brain hematomas or tumors, a high tracer uptake was visible in lesions on early images, but the radioactivity in lesions varied with the histologic nature of the lesion on delayed images. The radioactivity decreased remarkably in brain hematomas (average retained index, 0.61 +/- 0.04). The radioactivity was stable or decreased slightly in benign or low-grade tumors (average retained index, 0.96 +/- 0.24). The radioactivity was increased in high-grade or metastatic tumors (average retained index, 1.26 +/- 0.28). CONCLUSION: This study indicates that 201Tl brain SPECT early and delayed imaging is very useful in brain tumor localization, in distinguishing low-grade from high-grade brain tumors, in predicting histologic grades of brain tumors, and in detecting residual or recurrence of brain tumors postoperatively. 201Tl brain SPECT may also offer the most accurate assessment of response to therapy.
Adult↗
Effect of telomere and telomerase interactive agents on human tumor and normal cell lines.
Shortening of telomeres along with an up-regulation of telomerase is implicated in the immortality of tumor cells. Targeting either telomeres or telomerase with specific compounds has been proposed as an anticancer strategy. Because telomerase activity and telomeres are found in normal cells, telomere or telomerase targeting agents could induce side effects in normal tissues. We evaluated the effects of telomere and telomerase interactive agents in human tumor and normal cell lines to try to determine the potential side effects those agents might induce in patients. Toxicity of the G-quadruplex interactive porphyrins (TMPyP4, TMPyP2) and azidothymidine (AZT) were tested using a cell-counting technique against normal human cell lines (CRL-2115 and CRL-2120, fibroblasts; NHEK-Ad, adult keratinocytes; CCL-241, small intestinal cells; NCM 460, colonic mucosal epithelial cells) and human tumor cell lines (MDA-MB 231 and Hs 578T, breast cancer; SK-N-FI, neuroblastoma; HeLa, cervix cancer; MIA PaCa-2, pancreatic cancer; HT-29 and HCT-116, colon cancer; DU 145, prostatic cancer cell line). Telomerase activity of these cell lines was measured by a non-PCR-based conventional assay. The effects of TMPgammaP2, TMPyP4, and AZT were also evaluated against normal human bone marrow specimens, using a granulocyte-macrophage colony-forming assay (CFU-GM). AZT showed very low cytotoxic effects against normal and tumor cell lines, with the IC50 values above 200 microM. The IC50 values for TMPyP2 and TMPyP4 in normal human cell lines were in the range of 2.9-48.3 microM and 1.7-15.5 microM, respectively, whereas in tumor cell lines the IC50 values were 11.4-53 microM and 9.0-28.2 microM, respectively. Within the tissue types, keratinocytes were more sensitive to TMPyP4 than fibroblasts, and small intestinal cells were more sensitive than colonic mucosal epithelial cells. The IC50 for TMPyP2 and TMPyP4 in the normal marrow colony-forming assays were 19.3 +/- 5.1 microM and 47.9 +/-1.0 microM, respectively. In conclusion, the in vitro cytotoxicity of the telomere interactive agent TMPyP4 is comparable in human tumor and normal cell lines, which indicates that TMPyP4 could have effects on normal tissues.
Bone Marrow Cells↗
[A self-adaptable system for acquiring and processing animal ECG parameters].
The present authors have developed a computerized system for acquiring and processing the animal ECG. The system provides many functions in the software design and the users can compile the parameter-analyzing formulae by themselves according to the characteristics of ECG. The system is much more accurate and flexible in analyzing the ECG parameters and can significantly avoid the processing mistakes caused by signal variations and interference. It is especially suitable for continuous ECG monitoring and analysis of animal experiments in physiology, pharmacology and toxicology.
Animals↗
Effects of morphine on rheological properties of rat red blood cells.
To evaluate the effect of morphine on red blood cells, in vivo and in vitro rat models of morphine dependence were established. Rheological properties of rat red cells were measured by ektacytometry; the biophysical changes in the membrane of rat red cells were measured by the Fourier-Transformed Infrared technique (FT-IR) and the fluorescence depolarization method. The results show that the membrane fluidity of red cells was greatly reduced by morphine and the secondary structure of membrane proteins was changed. This suggests that morphine affects the rat red cell membrane directly, rather than through opioids-receptors.
Animals↗
A study of hemorheological behaviour for patients with Alzheimer's disease at the early stages.
To evaluate the change of hemorheological indexes for patients with Alzheimer's disease (AD) at the early stages and to discuss effects of these changes on AD, high shear value of whole blood viscosity (etabh), reduced high shear value of whole blood viscosity (retabh), low shear value of whole blood viscosity (etabl), reduced low shear, value of whole blood viscosity (retabl), KT value of whole blood viscosity, hematocrit (HCT) and blood plasma viscosity (etaP) were measured in 31 patients with probable AD at the early stages and 33 age-matched healthy subjects. There were significant differences of all hemorheological indexes between AD group and control group except HCT. Step discriminant analysis revealed 81.25% of overall group-classified accuracy in a hemorheological discriminant function consisting of etabl, retabl, retabh and HCT. Significant difference of hemorheological indexes existed between AD and age-matched healthy control subjects. The results showed that measurement of hemorheological indexes could be used as one of reference standards of diagnosis in AD.
Aged↗
Influence of neuraminidase on the characteristics of microrheology of red blood cells.
Surface charge was removed from RBC (erythrocyte) membrane to different degrees with biochemical methods, i.e., treatment of RBCs with neuraminidase, either using different doses for the same incubation time (1 hour) or using the same dose (75 milli-unit) for different incubation time. Several rheological properties of the RBCs with surface charge removal were observed, including the deformation index DI (using traditional ektacytometry) orientation index (DI)or and small deformation index (Dl)d (using new ektacytometry), the viscosity at low and high shear rates (using a cone-plate rotating viscosimeter). In addition, photographs of RBCs aggregation under a microscope and the histograms of RBC aggregate size after treatment with neuraminidase were obtained. It is found from these experiments that the decrease of the surface charge of RBCs leads to the decrease in the deformation and orientation indices as well as the increase in blood viscosity.
Animals↗
[An experimental study of rat infected with human cytomegalovirus AD169 strain].
OBJECTIVE: To study the sensitivity of rat to human cytomegalovirus (HCMV) infection and to establish a stable animal model. METHODS: Two kinds of rat experiments were carried out: 1) 30 SD rats were divided into three groups randomly, they were virus inoculated group, inactivated virus inoculated group and the normal rat group respectively; 2) 40 Wistar rats were randomly divided into two groups, they were the virus inoculated group and the inactivated virus inoculated group. All the rats were inoculated through tail vein. 90 d later, the rat's tissue lesions were observed by pathological techniques, HCMV antigen was detected by immunohistochemical method and the HCMV DNA was analyzed by in situ hybridization. RESULTS: The extensive pathological damages in tissues of HCMV infected rats were observed. Meanwhile, the viral antigen and viral DNA were also demonstrated in many tissues of HCMV infected rats. CONCLUSIONS: Rat is sensitive to infection of HCMV strain, but, as an animal model study, we still have a lot of works to do.
Animals↗
Relationship between the renin-angiotensin system genes and diabetic nephropathy in the Chinese.
OBJECTIVE: To clarify whether genetic variants of the renin-angiotensin system (RAS) contribute to the development of diabetic nephropathy (DN) in the Chinese. METHODS: Totally 173 Chinese subjects of Han nationality from Shanghai were classified into! control, DN (-) and DN (+) groups. The latter was subdivided according to diabetic duration at the onset of DN and the stage of DN. Genotyping of five polymorphic sites in four key genes of the RAS: the AGT-T174M, AGT-M235T and AGTR1 genotypes were determined by PCR/restriction enzyme digestion. The insertion/deletion (I/D) and [ACAC] n-STR microsatellite polymorphic markers were used for ACE and REN genotyping, respectively. Statistical analysis showed comparisons of gene frequencies between any two groups were made with Fisher's exact test or Chi-square test. Logistic regression analysis was performed to identify predictors of DN. RESULTS: The frequencies of ACE-DD genotype and ACE-D allele were much higher in DN(+) group than in DN (-) group (0.25 vs 0.05, 0.47 vs 0.29, respectively), so were the frequencies of TT genotype and T allele in AGT-M235T (0.73 vs 0.54, 0.85 vs 0.68, respectively). DN (+) DUR < 5 years group had greatly increased frequencies of AGT-M235T allele and ACE-DD genotype in comparison with DN(-) group (0.92 vs 0.68 and 0.28 vs 0.05, respectively). Logistic regression analysis further identified these two genes as contributing factors to DN. Although AGTR1 and AGT-T174M genotyping analysis revealed differences in frequency distribution between DN (+) and DN (-) or control groups, logistic regression analysis failed to implicate them in the development of DN. CONCLUSIONS: Our study revealed RAS genes, ACE and AGT-M235T but not AGT-T174M, AGTR1 or REN genotypes, as contributing factors for DN in type 2 diabetes mellitus in Chinese.
Aged↗
Complications in laparoscopic gynecologic surgery.
OBJECTIVE: To investigate retrospectively the complications and associated factors of gynecolgical laparoscopies. METHODS: 1 769 laparoscopic surgeries were carried out from January 1994 to October 1999 at our department. The procedures included 1421 surgeries of ovary and tube, 52 myomectomies and 296 cases of laproscopic-assisted vaginal hysterectomy (LAVH). A total of 312 patients had a history of prior laparotomy (17.6%). RESULTS: Complications occured in 34 cases, the overall complication rate was 1.92%. Unintended laparotomies occured in 6 cases (0.34%). 12 complications were associated with insertion of Veresse needle or trocar and creation of pneumoperitoneum, including 5 severe emphysema and 7 vascular injuries, this figure represents 35.3% of all complications of this series. Five intraoperative complications (14.7%) occured during the laparoscopic surgery (3 severe bleedings, one bladder injury and one skin burn of leg caused by damaged electrode plate), laparotomy was required in four of these cases. Seventeen complications occured during postoperative stage: 2 intraperitoneal hemorrhages needing laparotomy, 2 bowel injuries, 4 nerve paresis and 9 febrile morbidities. CONCLUSIONS: Operative gynecologic laparoscopy is associated with acceptable morbidity rate, but can not be overlooked. Complication rate seems to be higher in advanced procedures such as LAVH.
Female↗
[Spectral interferences of rare earth elements with a high resolution sequential ICP-AES. IV. Spectral interferences of europium and gadolinium].
The spectral interferences of Eu and Gd(100 micrograms.mL-1, separately) as matrices on the other REEs(1 or 5 micrograms.mL-1) were studied with a high resolution sequential ICP-AES with a grating of 3,600 grooves/mm. Totally 66 prominent lines of 14 REEs were selected as the analytical lines for the spectral interference studies. The overlapping profiles of analytical lines and interference lines were obtained by scanning four solutions(blank, analyte, Eu matrix, and Gd matrix, individually) within the selected wavelength windows (0.2 nm for each analytical line). Some new emission lines of Eu and Gd were observed. The obtained information of spectral interferences would be very useful for the selection of the best analytical lines for the determination of REEs in the other REEs matrices.
Europium↗
[Spectral interferences of rare earth elements observed with a high resolution inductively coupled plasma atomic emission spectrometer. V. Spectral interferences of lutetium, thulium, yttrium and ytterbium as matrices].
The spectral interferences of Lu, Tm, Y and Yb (100 microns.mL-1, separately) as matrices on the other REEs (1 or 5 microns.mL-1) were observed with a high resolution ICP-AES with a grating of 3,600 grooves.mm-1. Totally 66 analytical lines of 15 REEs were selected as the prominent lines for spectral interference studies. The "Q" values and "the true detection limit" were calculated for the selected prominent lines with the exist of the four matrix elements. The obtained information is useful in the selection of the best analytical lines for the determination of REEs in the other REEs' matrices.
Lutetium↗
Heats of adsorption of some organic compounds on beta-cyclodextrin determined by gas-solid chromatography.
Isosteric adsorptive enthalpies have been derived from the temperature dependence of retention volumes determined by eluted pulse gas-solid chromatography. The heat data were obtained for systems using more than 20 organic liquids as adsorbates, and beta-cyclodextrin as adsorbent. The experimental results have been discussed in the light of intermolecular force between molecules of adsorbate and adsorbent.
Adsorption↗
Microtubule actin cross-linking factor (MACF): a hybrid of dystonin and dystrophin that can interact with the actin and microtubule cytoskeletons.
We cloned and characterized a full-length cDNA of mouse actin cross-linking family 7 (mACF7) by sequential rapid amplification of cDNA ends-PCR. The completed mACF7 cDNA is 17 kb and codes for a 608-kD protein. The closest relative of mACF7 is the Drosophila protein Kakapo, which shares similar architecture with mACF7. mACF7 contains a putative actin-binding domain and a plakin-like domain that are highly homologous to dystonin (BPAG1-n) at its NH(2) terminus. However, unlike dystonin, mACF7 does not contain a coiled-coil rod domain; instead, the rod domain of mACF7 is made up of 23 dystrophin-like spectrin repeats. At its COOH terminus, mACF7 contains two putative EF-hand calcium-binding motifs and a segment homologous to the growth arrest-specific protein, Gas2. In this paper, we demonstrate that the NH(2)-terminal actin-binding domain of mACF7 is functional both in vivo and in vitro. More importantly, we found that the COOH-terminal domain of mACF7 interacts with and stabilizes microtubules. In transfected cells full-length mACF7 can associate not only with actin but also with microtubules. Hence, we suggest a modified name: MACF (microtubule actin cross-linking factor). The properties of MACF are consistent with the observation that mutations in kakapo cause disorganization of microtubules in epidermal muscle attachment cells and some sensory neurons.
Actin Cytoskeleton↗
Regulatory T cells in experimental allergic encephalomyelitis. II. T cells functionally antagonistic to encephalitogenic MBP-specific T cells show persistent expression of fasL.
Naive LEW rats and animals that have recovered from active or adoptive EAE contain a subset of T cells that inhibit EAE in secondary recipients and are lytic for MBP-reactive T cell lines in culture. Here we explore various features of these regulatory T cell populations (RTC) with respect to (1) their frequency in animals following immunization with syngeneic MBP-reactive cell lines, (2) their ability to inhibit proliferative responses by MBP-reactive cell lines in culture, (3) their ability to lyse MBP-specific target cells, and especially (4) their prolonged expression of high levels of FasL following activation in culture correlating with their lytic effects on A20, a FasL-sensitive mouse lymphoma cell line. Inhibition studies indicate that mAbs specific for MHC class I and MHC class II molecules inhibit lysis of syngeneic MBP-reactive target T cells, soluble Fas protein shows some inhibition, but none of these agents inhibits the lytic effects of activated RTC on the A20 cell line.
Animals↗
Alanine-substituted peptide ligands differ greatly in their ability to activate autoreactive T-cell subsets specific for the wild-type peptide.
Alanine-substituted peptide ligands (APLs) have the potential to reduce or block autoreactive T-cell activation. Most previous investigations aimed at either identification of the amino acid residue within a peptide ligand that is critical for T-cell activation or characterization of inhibitory APLs have analyzed the effects of APLs on one, or a limited number, of T-cell lines. In this study, we compared the effects of a panel of peptides on the proliferative and activation responses of one T-cell line as well as the effects of one peptide on the responses of a panel of T-cell lines. This study reveals that the T cells that comprise the T-cell population that responds to a specific peptide are heterogeneous in that an APL may fail to induce a response in some of these T cells although it is capable of inducing a response in the others. Moreover, APLs can induce T-cell activation, in terms of production of IL-2 and/or TNF-alpha, in the absence of appreciable cell proliferation. Indeed, despite being poor stimulators in proliferation assays, most APLs readily induce production of TNF-alpha. Our results demonstrate that the net outcome of APL treatment in vivo represents the sum of diverse effects, which may not be revealed completely by limited and randomly chosen in vitro assays.
Alanine↗
Lepidopteran DALP, and its mammalian ortholog HIC-5, function as negative regulators of muscle differentiation.
During myogenesis, reductions in trophic factor availability signal most myoblasts to fuse, up-regulate the expression of muscle-specific genes, and form myotubes. Those cells failing to differentiate into myotubes initiate apoptosis and rapidly die. At present, the signal-transduction molecules that determine whether myoblasts should differentiate or die are largely unknown. In this report, we describe the cloning and characterization of DALP, a small LIM-only type zinc-finger protein that is induced when the intersegmental muscles (ISMs) of the moth Manduca sexta become committed to die at the end of metamorphosis. Forced expression of death-associated LIM-only protein (DALP) in Drosophila results in skeletal muscle atrophy. Ectopic expression of DALP, or its mammalian ortholog Hic-5, blocks differentiation and induces apoptosis in mouse C(2)C(12) myoblasts. Both of these effects can be overcome by contact with normal myoblasts or by ectopic expression of the muscle-specific transcription factor MyoD. Hic-5 expression is specifically and dramatically induced in normal myoblasts that die after removal of trophic support. Taken together, these data suggest that DALP and Hic-5 act upstream of MyoD and function as phylogenetically conserved "switches" to block muscle differentiation and induce death.
Amino Acid Sequence↗