Biomedical subjects

R Sun

Publications and source records attributed to R Sun.

At least 37 records · Page 2Linked to original sources

PubMed2001

Intestinal-enriched Krüppel-like factor (Krüppel-like factor 5) is a positive regulator of cellular proliferation.

Intestinal-enriched Krüppel-like factor (IKLF or KLF5) belongs to the family of mammalian Krüppel-like transcription factors. Previous studies indicate that expression of IKLF is enriched in the proliferating crypt epithelial cells of the intestinal tract. However, the biological function of IKLF is unknown. In the current study, we have shown that the level of IKLF mRNA was nearly undetectable in serum-deprived NIH3T3 fibroblasts but became acutely and significantly increased upon the addition of fetal bovine serum or the phorbol ester, PMA. This induction required protein synthesis because it was prevented by cycloheximide. Transfection of IKLF into NIH3T3 cells resulted in the formation of foci in a manner similar to that caused by the activated Ha-ras oncogene. Constitutive expression of IKLF in transfected NIH3T3 cells significantly increased the rate of proliferation when compared with cells transfected with an empty vector. The growth of IKLF-transfected cells was no longer inhibited by cell-cell contact or by low serum content. Moreover, these cells proliferated in an anchorage-independent fashion. We conclude that IKLF encodes a delayed early response gene product that positively regulates cellular proliferation and may give rise to a transformed phenotype when overexpressed.

3T3 Cells↗

PubMed2001

Intraoperative management of posterior capsule tears in phacoemulsification and intraocular lens implantation.

OBJECTIVE: This paper presents the incidence, causes, and management of posterior capsule (PC) tears and their postoperative outcomes in a large series of eyes that underwent cataract removal and intraocular lens (IOL) implantation, operated on by one surgeon. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Eighteen thousand four hundred seventy consecutive eyes (1992-1999) were reviewed with the assistance of electronic medical records for incidence of PC tears in patients seeking treatment at an outpatient cataract surgery clinic. INTERVENTION: Eyes in this series underwent continuous curvilinear capsulorrhexis (CCC), nucleofractis phacoemulsification, and IOL implantation under topical anesthesia. Different intraoperative surgical strategies such as posterior continuous curvilinear capsulorrhexis (PCCC) were used in the management of PC tears. MAIN OUTCOME MEASURES: Routine preoperative and postoperative visual and refractive outcomes were recorded, including incidence of lens capsule tears, IOL position, and postoperative complications. RESULTS: Posterior capsule tears occurred in 83 of 18,470 eyes, resulting in an overall incidence of 0.45%. Of these 83 eyes with PC tears, 49% received vitrectomy. Fifty-one of 83 PC tears (61.4%) were amenable to be converted to PCCC. Of these 51 procedures, 50 eyes had PC IOL in-the-bag fixation. One eye had PCCC with optic capture. There were no eyes with dropped nuclei or nuclear fragments requiring pars plana vitrectomy. Seventeen eyes (20.5%) had Neuhann anterior capsule rhexis fixation with the haptics placed in the sulcus and IOL securely in the bag. Ten eyes (12.1%) had the IOL placed in the sulcus, and 5 eyes (6.0%) required anterior chamber IOL fixation. None of the 83 PC tears resulted in clinically evident cystoid macular edema, retinal detachment, or endophthalmitis. CONCLUSIONS: With an intact CCC and with conversion of PC tears to PCCC, in-the-bag fixation of IOLs can be achieved in most eyes.

Alberta↗

PubMed2001

Accuracy and predictability of intraocular lens power calculation after laser in situ keratomileusis.

PURPOSE: To study the accuracy and predictability of intraocular lens (IOL) power calculation in eyes that had laser in situ keratomileusis (LASIK). SETTING: Gimbel Eye Centre, Calgary, Alberta, Canada. METHODS: Refractive outcomes in 6 cataract surgery and lensectomy eyes after previous LASIK were analyzed retrospectively. Target refractions based on measured and refraction-derived keratometric values were compared with postoperative achieved refractions. Differences between target refractions calculated using 5 IOL formulas and 2 A-constants and achieved refractions were also compared. RESULTS: The refractive error of IOL power calculation in postoperative LASIK eyes was significantly reduced when refraction-derived keratometric values were used for IOL power calculation. Persistent residual hyperopia still occurred in some cases; this was corrected by hyperopic LASIK. Refractive results appeared more accurate and predictable when the Holladay 2 or Binkhorst 2 formula was used for IOL power calculation. CONCLUSION: Hyperopic error after cataract surgery in post-LASIK eyes was significantly reduced by using refraction-derived keratometric values for IOL power calculation. Persistent hyperopic error was corrected by hyperopic LASIK.

Adult↗

PubMed2001

Connectionist inference models.

The performance of symbolic inference tasks has long been a challenge to connectionists. In this paper, we present an extended survey of this area. Existing connectionist inference systems are reviewed, with particular reference to how they perform variable binding and rule-based reasoning and whether they involve distributed or localist representations. The benefits and disadvantages of different representations and systems are outlined, and conclusions drawn regarding the capabilities of connectionist inference systems when compared with symbolic inference systems or when used for cognitive modelling.

Animals↗

PubMed2001

Uncoupling protein1 mRNA, mitochondrial GTP-binding, and T4 5'-deiodinase of brown adipose tissue in euthermic Daurian ground squirrel during cold exposure.

Regulation of thermogenic activity and uncoupling protein1 (UCP1) expression in brown adipose tissue (BAT) were studied in euthermic Daurian ground squirrel after acute and chronic cold exposure at 4 degrees C. The UCP1 concentration was indirectly determined by titration with its specific ligand [3H]-labeled GTP, and Ucp1 mRNA was detected by using a [32P]-labeled antisense oligonucleotide probe. Both acute and chronic cold exposure stimulated up-regulation of Ucp1 mRNA. Although UCP1 concentration is not significantly increased after 24 h of cold exposure, it is markedly elevated by 75% in squirrels after 4-week cold adaptation compared with controls raised at 22 degrees C. Changes in T4 5'-deiodinase activity were closely associated with variations of Ucp1 mRNA level. Ucp1 gene expression is significantly affected by cold exposure in BAT from euthermic Daurian ground squirrels. In addition, the activation of T4 5'-deiodinase may be an important regulatory factor in cold-induced Ucp1 expression.

Adaptation, Physiological↗

PubMed2001

Cold adaptive thermogenesis in small mammals from different geographical zones of China.

The mechanisms of thermogenesis and thermoregulation were studied in the tree shrew (Tupaia belangeri) and greater vole (Eothenomys miletus) of the subtropical region, and Brandt's vole (Microtus brandti), Mongolian gerbil (Meriones unguiculatus), Daurian ground squirrel (Spermophilus dauricus) and plateau pika (Ochotona curzoniae) of the northern temperate zone. Resting metabolic rate (RMR) and non-shivering thermogenesis (NST) increased significantly in T. belangeri, E. miletus, M. brandti and M. unguiculatus after cold acclimation (4 degrees C) for 4 weeks. In T. belangeri, the increase in RMR and thermogenesis at liver cellular level were responsible for enhancing the capacity of enduring cold stress, and homeothermia was simultaneously extended. Stable body temperature in M. brandti, E. miletus, M. unguiculatus and O. curzoniae was maintained mainly through increase in NST, brown adipose tissue (BAT) mass and its mitochondrial protein content, and the upregulation of uncoupling protein (UCP1) mRNA, as well as enhancement of the activity of cytochrome C oxidase, alpha-glycerophosphate oxidase and T(4) 5'-deiodinase in BAT mitochondria. The RMR in O. curzoniae and euthermic S. dauricus was not changed, while NST significantly increased during cold exposure; the former maintained their stable body temperature and mass, while body temperature in the latter declined by 4.8 degrees C. The serum T(3) concentration or ratio of T(3)/T(4) in all the species was enhanced after cold acclimation. Results indicated that: (1) the adaptive mechanisms of T. belangeri residing in the subtropical region to cold are primarily by increasing RMR and secondly by increasing NST, and the mechanisms of thermogenesis are similar to those in tropical mammals; (2) in small mammals residing in northern regions, the adaptation to cold is chiefly to increase NST; (3) the mechanism of cold-induced thermogenesis in E. miletus residing in subtropical and high mountain regions is similar to that in the north; (4) a low RMR in warm environments and peak RMR and NST in cold environments enabled M. unguiculatus to tolerate a semi-desert climate; (5) O. curzoniae has unusually high RMR and high NST, acting mainly via increasing NST to adapt to extreme cold of the Qinghai-Tibet Plateau; (6) the adaptation of euthermic S. dauricus to cold is due to an increase in NST and a relaxed homeothermia; and lastly (7) the thyroid hormone is involved in the regulation of cold adaptive thermogenesis in all the species studied.

Adaptation, Physiological↗

PubMed2001

Bioactive aromatic compounds from leaves and stems of Vanilla fragrans.

Alcoholic extracts of leaves and stems of Vanilla fragrans were fractionated with ethyl acetate and aqueous butanol. All three fractions of ethyl acetate, butanol, and water were screened for toxic bioactivity against mosquito larvae. The results of these experiments showed that the fractions from the ethyl acetate and butanol phases were both active in the bioassay. Bioactivity of the ethyl acetate fraction was found to be much greater than that from the butanol fraction in mosquito larvae toxicity. The water phase appeared to contain no substances that impaired mosquito larval growth. Repeated column chromatography of the ethyl acetate fraction on silica gel led to the isolation of 4-ethoxymethylphenol (1), 4-butoxymethylphenol (2), vanillin (3), 4-hydroxy-2-methoxycinnamaldehyde (4), and 3,4-dihydroxyphenylacetic acid (5). Compounds 4 and 5 were isolated from Vanilla species for the first time and 2 has not been reported to have been found in a natural form. 4-Ethoxymethylphenol (1) was the predominant compound, but 4-butoxymethylphenol (2) showed the strongest toxicity to mosquito larvae. The structures of the compounds were determined on the basis of their mass spectra and (1)H or (13)C NMR data.

Animals↗

PubMed2001

Microencapsulated bovine chromaffin cell xenografts into hemiparkinsonian rats: a drug-induced rotational behavior and histological changes analysis.

Bovine chromaffin cells were microencapsulated within alginate-polylysine-alginate (APA) membranes. Microencapsulated bovine chromaffin cells as well as unencapsulated cells and empty microcapsules were grafted into the brain of hemiparkinsonian rats with 6-hydroxydopamine (6-OHDA) lesions. Apomorphine-induced rotational behavior of the host animals and the survival of the grafted chromaffin cells were examined after transplantation. The animals receiving microencapsulated bovine chromaffin cells showed a significant decrease (17.6--35.6%) in apomorphine-induced rotation 1 week postimplantation that remained stable for the 10 month test period. Fluorescent histochemistry further revealed that microencapsulation increased the chromaffin cell survival with only a minimum host reaction for up to 10 months posttransplantation while the survival of free, unencapsulated chromaffin cells was only modest and was accompanied by a large inflammatory response. The reduction of apomorphine-induced rotations was correlated with the survival of bovine chromaffin cells in the host brain. The data indicate that encapsulation of bovine chromaffin cells in APA membranes reduces the host immune response to the xenograft and prolongs the viability of the grafted cells.

Animals↗

PubMed2001

Performance characteristics of the COBAS AmpliScreen HIV-1 test, version 1.5, an assay designed for screening plasma mini-pools.

BACKGROUND: The COBAS AmpliScreen HIV-1 test, version 1.5 (v1.5) (Roche Molecular Systems), is designed for screening pools composed of samples from 24 individual units of blood or plasma. A specimen-processing procedure (Multiprep) simultaneously concentrates and extracts HIV-1, HCV, and HBV particles from plasma and incorporates an HIV-1 internal control (IC) RNA. Processed samples are amplified by RT-PCR using HIV-1-specific primers and detected by hybridization of the amplified products to HIV-1- and IC-specific oligonucleotide probes. STUDY DESIGN AND METHODS: Plasma samples containing known quantities of HIV-1 were used to evaluate analytical sensitivity and precision and to validate a pool testing algorithm. Analytical specificity was evaluated by adding various viruses and bacteria to HIV-1-negative plasma. Seroconversion panels were tested to estimate the window-period reduction achieved by RNA testing. RESULTS: The analytical sensitivity of the test (concentration that yields > or = 95% positive results in a set of replicate tests) was 25 copies of HIV-1 RNA per mL of pooled plasma. Representative strains from all HIV-1 group M subtypes were reproducibly detected (> 95% positive results) at concentrations of 20 to 200 viral particles per mL. The test did not cross-react with a set of 31 viral and 5 bacterial isolates, and it yielded negative results on a panel of 500 blood samples from HIV-1-seronegative donors. Plasma samples containing abnormally high levels of Hb, albumin, triglycerides, or bilirubin did not interfere with the test. HIV-1 RNA was detected 2 to 14 days before HIV-1 antibody and 0 to 28 days before p24 antigen. The test specifically detected pools containing a single positive unit with 2400 HIV-1 RNA copies per mL and correctly identified the positive unit. CONCLUSION: The COBAS AmpliScreen HIV-1 test, v1.5, has sufficient sensitivity to detect a single infected unit containing 600 copies of HIV-1 per mL in a pool with 23 uninfected units and should reduce the window period between infection and seroconversion by at least 2 to 14 days.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Function of Rta is essential for lytic replication of murine gammaherpesvirus 68.

Rta, encoded primarily by open reading frame 50, is well conserved among gammaherpesviruses. It has been shown that the Rta proteins of Epstein Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV, or HHV-8), and murine gammaherpesvirus 68 (MHV-68; also referred to as gamma HV68) play an important role in viral reactivation from latency. However, the role of Rta during productive de novo infection has not been characterized in gammaherpesviruses. Since there are cell lines that can support efficient productive de novo infection by MHV-68 but not EBV or KSHV, we examined whether MHV-68 Rta plays a role in initiating viral lytic replication in productively infected cells. Rta, functioning as a transcriptional activator, can activate the viral promoter of early lytic genes. The amino acid sequence alignments of the Rta homologues suggest that the organizations of their functional domains are similar, with the DNA binding and dimerization domains at the N terminus and the trans-activation domain at the C terminus. We constructed two mutants of MHV-68 Rta, Rd1 and Rd2, with deletions of 112 and 243 amino acids from the C terminus, respectively. Rd1 and Rd2 could no longer trans-activate the promoter of MHV-68 gene 57, consistent with the deletions of their trans-activation domains at the C terminus. Furthermore, Rd1 and Rd2 were able to function as dominant-negative mutants, inhibiting trans-activation of wild-type Rta. To study whether Rd1 and Rd2 blocked viral lytic replication, purified virion DNA was cotransfected with Rd1 or Rd2 into fibroblasts. Expression of viral lytic proteins was greatly suppressed, and the yield of infectious viruses was reduced up to 10(4)-fold. Stable cell lines constitutively expressing Rd2 were established and infected with MHV-68. Transcription of the immediate-early gene, rta, and the early gene, tk, of the virus was reduced in these cell lines. The presence of Rd2 also led to attenuation of viral lytic protein expression and virion production. The ability of Rta dominant-negative mutants to inhibit productive infection suggests that the trans-activation function of Rta is essential for MHV-68 lytic replication. We propose that a single viral protein, Rta, governs the initiation of MHV-68 lytic replication during both reactivation and productive de novo infection.

Animals↗

PubMed2001

Transcription activation of polyadenylated nuclear rna by rta in human herpesvirus 8/Kaposi's sarcoma-associated herpesvirus.

Human herpesvirus 8 (HHV-8) (also known as Kaposi's sarcoma-associated herpesvirus) encodes a novel noncoding polyadenylated nuclear (PAN) RNA (also known as T1.1 or nut-1) during the early phase of lytic replication. PAN RNA is the most abundant transcript of HHV-8, comprising 80% of total poly(A)-selected transcripts in HHV-8-infected cells during lytic replication. We directly measured the abundance of PAN RNA by visualizing 1.1- to 1.2- kb PAN RNA in an ethidium bromide-stained gel from poly(A)-selected RNA. We further pursued the mechanisms by which PAN RNA expression is induced to such high levels. rta, an immediate-early gene of HHV-8, is a transactivator that is sufficient and necessary to activate lytic gene expression in latently infected cells. Ectopic expression of Rta was previously shown to induce PAN RNA expression from the endogenous viral genome and activate the PAN promoter in a reporter system. Here, we have identified the Rta-responsive element (RRE) in the PAN promoter. Deletion analysis revealed that the RRE is present in a region between nucleotides -69 and -38 of the PAN promoter. A promoter construct containing the 69 nucleotides upstream of the transcription start site of the PAN promoter was activated by Rta in the absence or presence of the HHV-8 genome. Rta activated the PAN promoter up to 7,000-fold in 293T cells and 2,000-fold in B cells. Electrophoretic mobility shift assays demonstrated that Rta formed a highly stable complex with the RRE of the PAN promoter. Our study suggests that Rta can induce PAN RNA expression by direct binding of Rta to the RRE of the PAN promoter. This study has highlighted an important mechanism controlling PAN RNA expression and also provides a model system for investigating how Rta transactivates gene expression during lytic replication.

Animals↗

PubMed2001

[Purification and biological activity of rh-leptin expressed in Escherichia coli].

The human leptin was successfully expressed with high level in E. coli under the control of PL promotor. The yield of recombinant protein was over 40% of total cellular protein and expressed as inclusion bodies. The recombinant human leptin (rh-leptin) was purified with gel filtration, anion-exchange and reverse chromatography. Refolding was achieved by gradually reducing denaturant using a diafiltration method. The refolded rh-leptin was characterized by SDS-PAGE, Western-blotting and its first 15 amino acid residues sequence of the N-terminal. The purified product was found to be biologically active, reducing the food intake and body weight gain upon testing in BALB/c mice.

Animals↗

PubMed2001

[Study of the cytotoxity against human hepatocellular carcinoma cells induced by the MAGE-1 gene modified dendritic cells].

OBJECTIVE: To genetically modify dendritic cells (DC) with a tumor associated antigen gene MAGE-1 and to observe in vitro the cytotoxic effect induced by this genetically modified DC against human hepatocellular carcinoma (HCC) cell line SMMC7721, thus giving a primary verification of the possibility of this genetically modified DC to induce specific antitumor immunity against HCC and serving as a new type of vaccine. METHODS: The MAGE-1 gene was inserted into the retrovirus vector LXSN to construct the recombinant retrovirus LMSN. The monocyte-derived DCs were transfected by LMSN and control virus LXSN respectively as well as a third group was set up as non-transfected control. The MAGE-1 gene expression in LMSN transfected DC was identified by Western blot and the in vitro cytotoxities against SMMC7721 induced by three groups of DC were tested by MTT assay. RESULTS: A recombinant retrovirus LMSN containing the tumor rejection antigen gene MAGE-1 was successfully constructed and the MAGE-1 gene expression in LMSN transfected human monocyte-derived DC was induced. The LMSN transfected DC could induce very high lytic activity against SMMC7721 in vitro with the lytic activity of 78.9%+/-3.6%. Nevertheless, the LXSN transfected DC and non-transfected DC only induced relatively lower lytic activity as 34.7%+/-4.3% and 3.9%+/-2.0%, respectively. The difference of the lytic activities between those three groups as statistically significant (P<0.01). CONCLUSIONS: The MAGE-1 gene transfected DC can induce higher in vitro cytotoxicity against SMMC7721, suggesting the possibility of this genetically modified DC to induce specific antitumor activity and to serve as a new type of vaccine for HCC.

Animals↗

PubMed2001

[Effects of interferon-alpha on recurrence and metastasis of hepatocellular carcinoma after curative resection in nude mice].

OBJECTIVE: To study the effect of interferon-alpha (IFN-alpha) on the recurrence and metastasis of hepatocellular carcinoma (HCC) in nude mice, and to clarify if there is synergistic effect treated by combination of IFN-alpha and all-trans retinoic acid (ATRA). METHODS: The effect of IFN-alpha and/or ATRA on the proliferation of HCC cell lines was measured in vitro. The metastatic model of human HCC in nude mice LCI-D20 was used in present study. Curative resection was performed at 10th day after implantation in 44 nude mice. Drugs were given at the next day after resection. IFN-alpha was administered subcutaneously at doses of 3+/-10(5) U/day, 6+/-10(5) U/day, respectively. ATRA was administered p.o. at a dose of 20 mg/kg/day, and IFN-alpha 6+/-10(5)U/day combined with ATRA 20 mg/kg/day. The mice were sacrificed 35 days after treatment. The recurrent tumor size was measured and the presence of intrahepatic dissemination and lung metastases were recorded. RESULTS: The effect of IFN-alpha and/or ATRA on the proliferation of HCC cells SMMC7721, BEL-7402, BEL-7405, and MHCC97 was not obvious. The combination of IFN-alpha and ATRA had no synergistic effect in vitro. The lung metastatic rate, the liver recurrent rate, the size of main recurrent lesions, the number of intrahepatic disseminating nodules and the largest disseminating nodule of the controlled group was 100%(12/12), 100%(12/12), (1346.3+/-4.2 ) mm(3), 8.2+/-4.4, 864 mm(3), respectively; whereas it was 0, 87.5%(7/8), (8.7+/-2.9) mm(3), 2.3+/-0.6, and 7.8mm(3), respectively in the IFN-alpha 3+/-10(5) U/day treated group(P<0.05); 0, 12.5%(1/8), 0.5mm(3), 2, 0.5 mm(3) in the IFN-alpha 6+/-10(5)U/day treated group(P<0.05); 0, 12.5%(1/8), 1 mm(3), 2.5+/-0.7, 8 mm(3) in the IFN-alpha 3+/-10(5) U/day and ATRA treated group(P<0.05); 87.5%, 100%, (1472.6+/-5.6) mm(3), 7.3+/-3.8, 768.5 mm(3) in the ATRA treated group (P>0.05). CONCLUSIONS: IFN-alpha has an inhibitory effect on intrahepatic recurrence and lung metastasis of human HCC after curative resection in nude mice, and the effect is enhanced with increasing dose. IFN-alpha and ATRA have no synergistic effect according to in vivo and in vitro test. ATRA has no effect on recurrence and metastasis of HCC.

Animals↗

PubMed2001

[Significance of the unbalanced expression of Th1/Th2 type cytokines in human glioma].

OBJECTIVE: To study the significance of the unbalanced expression of Th1/Th2 type cytokines in human glioma. METHODS: The gene expressions of Th1/Th2 type cytokines in 62 specimens of human glioma tissues, 4 glioma cell lines, peripheral blood mononuclear cell (PBMC) of 15 glioma patients, 5 specimens of normal adult brain tissue and 5 brain meningioma tissues were detected by semiquantitative reverse transcription polymerase chain reaction. IFN-gamma and IL-2 represent Th1 type cytokines. IL-4, IL-6, IL-10 and IL-13 represent Th2 type cytokines. RESULTS: There were obviously predominant expression of Th2 type cytokines in glioma cell lines (P < 0.01) and specimens of human glioma tissues (P < 0.01). The tendency of distinct expression of Th2 type cytokines in PBMC was also existent. There wasn't obvious discrepancy of the expression of two type cytokines in normal adult brain tissues and meningioma tissues. CONCLUSIONS: It is likely that the switching of Th1/Th2 type cytokines in gliomas as predominant expression of Th2 type cytokine genes is related to the origination of gliomas and the evasion of glioma cells from immune surveillance.

Adolescent↗

PubMed2001

[Influence of adjustment of balance of Th1/Th2 type cytokines on proliferation of glioma cells].

OBJECTIVE: To study the influence of adjustment of balance of Th1/Th2 by external cytokines on proliferation of glioma cells. METHODS: The gene expressions of Th1/Th2 type cytokines in C6, 9L, U251 and SHG44 glioma cells were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). After the cells were induced with IFN-gamma + IL-4 McAb and IL-4 + IFN-gamma McAb respectively, we isolated the total RNA to proceed RT-PCR again. The evaluation of cell proliferation was proceeded by MTT assay method. RESULTS: There was obviously predominant expression of Th2 type cytokines in glioma cell lines (P < 0.01). The expression intensity of IFN-gamma was improved in IFN-gamma + IL-4 McAb groups and Th2 type cytokines were enhanced in IL-4 + IFN-gamma McAb groups. IFN-gamma and IL-4 McAb could cause the switch from Th2 to Th1, and could remarkably inhibit the proliferation of glioma cells in a dose-dependent way (P < 0.01). On the other hand, IL-4 and IFN-gamma McAb could strengthen the switch of Th2, and might stimulate the glioma cell growth, also in a dose-dependent way (P < 0.01). CONCLUSIONS: There is a Th2 preponderance in glioma cells. IFN-gamma and IL-4 McAb could regulate the switch from Th2 to Th0 or Th1, and inhibit the proliferation of glioma cells.

Antibodies, Monoclonal↗

PubMed2001

[Differentiation of natural killer cells into two functional subsets: NKh1 and NKh2].

OBJECTIVE: To verify the presence of functional subsets of natural killer cells based on the cytokine production. METHODS: NK cells were purified and cultured in complete RPMI1640 medium in the presence of either IFN gamma + anti-IL-4(classical Th1 polarization) or IL-4 + anti-IFN gamma (classical Th2 polarization) for three days, and then were collected and detected for type I/type II cytokines by RT-PCR method. RESULTS: NK cells were purified from 15 healthy donors, over 70% purity of NK cells were determined by flow cytometry. NK cells in peripheral blood expressed high level of type I cytokines, mainly IFN gamma, but low level of type II cytokines such as IL-10 and IL-13, IL-4 was not produced by NK cells. Cells cultured in IFN gamma + anti-IL-4 condition exhibited significantly increased level of IFN gamma, unchanged IL-2, and decreased type II cytokines. Cells grew in IL-4 + anti-IFN gamma condition exhibited increased IL-10 and IL-13, and decreased IFN gamma expressions. CONCLUSIONS: Based on the cytokine production, NK cells may be divided into two functional subsets in the same manner as that of T lymphocytes(e.g. Th1/Th2): NKh1 and NKh2. The biological characterization and phenotypic marker are under investigate.

Cells, Cultured↗

PubMed2001

[The Raman spectra study on crystal-octadecyl hydrogen succinate crystal].

Raman spectra of crystal-octadecyl hydrogen succinate (OHS), whose geometric disposition of the experiment has y(zx)y, y(zz)y, and y(xz)y,y(xx)y respectively, have been recorded and analyzed with the purpose of understanding the structure of OHS crystal. It shows that some of the Raman-active modes of alkyl chain appear polarization. The analysis for crystal structure indicates that the molecular of OHS arrange in layers along [100] and [001] by the mode of dimers, and the molecular layers of chain pile up along [010]. The other groups of OHS corresponding Raman vibration peaks have been analyzed as well.

English Abstract↗