Bile regulates the expression of major histocompatibility complex class II molecules on rat intestinal epithelium

BACKGROUND & AIMS

Major histocompatibility complex (MHC) class II molecules are expressed on intestinal epithelial cells, and the intensity of this expression is regulated. The aim of this study was to test the hypothesis that bile regulates the expression of MHC class II molecules on intestinal epithelium.

METHODS

Rats were deprived of intestinal bile by external drainage for 24 or 48 hours, and their intestines were collected, sectioned, and stained with the anti-MHC class II monoclonal antibodies OX4 and OX6. For one group of rats, bile flow was deviated from its usual entry point to the ileum.

RESULTS

Compared with intact animals, MHC class II expression was observed to be diminished within 24 hours and totally absent after 48 hours of bile drainage. For the group in which bile flow was deviated to the ileum, staining was only observed in the region distal to the entry point. Analysis by bioassay and enzyme-linked immunosorbent assay of bile showed the presence of tumor necrosis factor and interferon gamma, respectively.

CONCLUSIONS

It is concluded that the presence of bile is required for the expression of MHC class II molecules on gut epithelium and that the cytokine components of bile may be the inducing agents.

[Purification and properties of inulinase from Kluyveromyces sp. Y-85]

The crude endocellular inulinase from Kluyveromyces sp. Y-85 was purified to two components, designated as EI and EII, using PEG6000-phosphate buffer extraction, (NH4)2SO4 fractionation, DEAE chromatography and gel filtration (Protein-PAK); The crude exocellular inulinase from this strain was purified to Eexo by means of PEG6000-phosphate buffer extraction, double DEAE-Sephace chromatography, Sephadex G-150 gel filtration. EI, EII and Eexo were demonstrated to be homogeneous by Waters 650E protein purification system. Their molecular weights are 42 kD, 65 kD and 57 kD, respectively. All the inulinases were glycoproteins containing a saccharide (from 25% to 35%) and belonged to the endo-inulinase. In addition, EI, EII, Eexo were optimally reactive at pH4.6, 4.5, 4.6 and at 52 degrees C, 52 degrees C, 55 degrees C, respectively. Ag+, Hg2+ and PCMB inhibited these enzymes' activity strongly. The products of raw inulin extracted from Helianthus tuberosus hydrolyzed by these three enzymes were fructose (86.5%) and glycose (13.5%).

Complementation of helper-dependent adenoviral vectors: size effects and titer fluctuations

The complementation of adenoviral vectors with large deletions in the viral genome was studied. The helper adenovirus used to complement these vectors contains a partial deletion of the packaging signal and the E1 region substituted by the lacZ gene. The effect of vector size on packaging efficiency was analysed in 293 cells using decreasingly shorter vectors expressing GFP from a CMV enhancer-beta-actin promoter. Vectors with longer genomes propagated more efficiently than shorter ones. Vectors containing only the packaging signal and the ITRs of Ad5, having all the viral genes replaced with unrelated sequences packaged as efficiently as vectors of the same size containing adenoviral DNA instead of exogenous DNA. The amounts of helper and vector produced in coinfected 293 cells exhibited the typical cycling fluctuation observed during serial propagation of a virus with defective interfering particles.

[Simultaneous determination of five carotenoids in tomato by reversed-phase high performance liquid chromatography]

A reversed-phase high performance liquid chromatographic method for the simultaneous determination of alpha-carotene, beta-carotene, gamma-carotene, lycopene and canthaxanthin in tomato has been developed. These carotenoids were extracted with acetone and petroleum ether (1:1) directly. The extract was dried by N2 stream. The residue was dissolved in methanol and separated on a micro-Bondapak C18 (Waters) column 150 mm x 3.9 mm i.d., acetonitrile:dichloromethane:methanol (85:10:5) as mobile phase. It was then detected at 450 nm by UV/VIS spectrophotometer. The retention times of alpha-carotene, beta-carotene, gamma-carotene, lycopene and canthaxanthin by simultaneous determination were 15.25, 16.12, 12.87, 10.38 and 5.37 min, respectively. Detection limits were 0.25, 0.22, 0.18, 0.14 and 0.05 mg/L. Recoveries were 92.38%, 94.33%, 92.40%, 93.21% and 96.40%, respectively. The coefficients of variation were 2.6%, 3.5%, 2.8%, 2.8% and 3.3%, respectively. The method was simple, rapid and accurate.

Studies on kochiae fructus. IV. Anti-allergic effects of 70% ethanol extract and its component, momordin Ic from dried fruits of Kochia scoparia L

The 70% ethanol extract (KS-ext) from Kochiae Fructus (dried fruits of Kochia scoparia L.) has been screened for activity in experimental models of type I-IV allergy. In type I allergic models, KS-ext at doses of 200 and 500 mg/kg, p.o. exhibited an inhibitory effect on 48-h homologous passive cutaneous anaphylaxis (PCA) in rats, which is related to IgE, and 1.5-h heterologous PCA in mice, which is related to IgG. In a type III allergic model, KS-ext showed an inhibitory effect on direct passive arthus reaction (DPAR) in rats, while it had no inhibitory effect on reversed cutaneous anaphylaxis (RCA) in a type II allergic model. Furthermore, in a type IV allergic model, KS-ext had an inhibitory effect on the effector phase in picryl chloride-induced contact dermatitis (PC-CD). Also, its anti-pruritogenic component, momordin Ic (oleanane saponin) exhibited inhibitory effects on 48-h homologous PCA and PC-CD. These results indicate that Kochiae Fructus not only inhibits humoral immunity but also influences cellular immunity, and should be recognized as a material for anti-allergic reactions. Also, the mode of its anti-pruritogenic activity may be mediated by anti-allergic action, and its active component may be partially attributed to momordin Ic.

A mutant truncated protein disulfide isomerase with no chaperone activity

A mutant human protein disulfide isomerase with the COOH-terminal 51 amino acid residues deleted (abb'a') has been expressed in Escherichia coli. Its secondary structures are very similar to those of the native bovine enzyme. The mutant enzyme shows neither peptide binding ability nor chaperone activity in assisting the refolding of denatured D-glyceraldehyde-3-phosphate dehydrogenase but keeps most of the catalytic activities for reduction of insulin and isomerization of scrambled ribonuclease. It assists the reactivation of denatured and reduced proteins containing disulfide bonds, acid phospholipase A2, and lysozyme to different levels, which are significantly lower than those by the native bovine enzyme.

Matrix-assisted laser desorption ionization mass spectrometry for the analysis of monosulfated oligosaccharides

Sulfated oligosaccharides are an important class of compounds in the field of glycobiology. Mass spectrometric analysis of these molecules is challenging due to their readiness to dissociate in sample preparation and their tendency to fragment during ionization. Moreover, their presence in small quantity in biological systems poses additional problems. We report the development of a mass spectrometric method based on matrix-assisted laser desorption ionization (MALDI) in a time-lag focusing time-of-flight mass spectrometer for the analysis of monosulfated oligosaccharides. It is found that coumarin 120 is an excellent matrix for the analysis of monosulfated disaccharides, whereas the use of a mixture of coumarin 120 and 6-aza-2-thiothymine is very effective for the ionization of sulfated trisaccharides and tetrasaccharides including those containing N-acetylneuraminic acid. Molecular ions for a series of synthetic sulfo/sialo beta Gal(1-->3)GlcNAc and beta Gal(1-->4)GlcNAc structures can thus be observed with subpicomole detection sensitivity using a uniform microcrystal matrix/sample preparation procedure. It is demonstrated that, with this matrix formulation, the presence of a high amount of sodium chloride or sodium phosphate buffer, which is often the case for the HPLC fractionated samples, does not deteriorate the MALDI performance. The analysis of mixtures containing different types of oligosaccharides is also examined. It is found that different classes of oligosaccharides require different matrix preparation methods.

Studies on kochiae fructus. III. Antinociceptive and antiinflammatory effects of 70% ethanol extract and its component, momordin Ic from dried fruits of Kochia scoparia L

The 70% ethanol extract (KS-ext) from Kochiae Fructus (dried fruits of Kochia scoparia L.) was screened for its activity on nociceptive and inflammatory responses in experimental animals. Although KS-ext at an oral administration of 500 mg/kg had an antinociceptive effect on writhing responses induced by acetic acid, it was ineffective on nociceptive response in the hot plate test. Oleanolic acid oligoglycoside, momordin Ic isolated from Kochiae Fructus significantly decreased the frequency of licking behavior within a unit of time at the late phase without affecting that of the early phase in the formalin test. Also, KS-ext inhibited the rise of vascular permeability induced by acetic acid, the increase of paw edema induced by carrageenin, histamine, serotonin or bradykinin and ear swelling induced by arachidonic acid. Momordin Ic also exhibited an inhibitory effect on carrageenin-induced edema. These results indicated that Kochiae Fructus has a peripheral antinociceptive effect mediated by antiinflammatory action, and that its active component can be partially attributed to momordin Ic.

P21/waf1 protein expression in nasopharyngeal carcinoma. Comparative study with PCNA, p53 and MDM-2 protein expression

We investigated the immunohistochemical expression of p21/waf1 protein in 59 cases of nasopharyngeal carcinomas (NPC) and compared p21 expression with PCNA, p53 and mdm2 protein expression. We found p21, PCNA, p53 and mdm2 in 59/59, 59/59, 18/59 and 12/59 nasopharyngeal carcinomas, respectively. We observed a tendency to a relationship between high expression of PCNA (> 25% positivity in tumour cells) and low expression of p21 protein. Parallel p53/p21 protein expression was found in 18 cases. Twelve were also mdm2 positive. This pattern may represent NPC with wild type (wt) p53 since mdm2 and p21 proteins are inducible by wt p53 gene. In these cases p53 protein expression may be due to stabilisation to mdm2 protein. This could be important in the pathogenesis of these cases since mdm2 may deregulate the p53-dependent growth suppressive pathway. Discordant p53-/p21+ protein expression was found in 41 cases. All were also mdm2 negative. This pattern suggests immunohistochemically undetectable wt p53 gene which is able to induce p21 protein expression.

Nuclear transfer in sheep embryos: the effect of cell-cycle coordination between nucleus and cytoplasm and the use of in vitro matured oocytes

The developmental ability of nuclear transplant sheep embryos derived from in vitro matured oocytes was studied by controlling cell-cycle coordination of donor embryonic nuclei and recipient cytoplasts. Oocytes were recovered from nonatretic antral follicles of adult sheep ovaries and cocultured with follicle shells in M199-based medium supplemented with gonadotrophins in a nonstatic system. Effective activation if IVM oocytes was obtained by applying two pulses of 1.0 kv/cm 22 min apart in inositol-based electroporation medium to oocytes matured in vitro for 27 hr. Synthesis of DNA (S-phase) was assessed by BrdU incorporation and was found to initiate around 5 hpa (hours postactivation) and to persist until 18 hpa. Mitotic blastomeres were induced by treating embryos with 6.6 microM nocodazole for 14-17 hr. Three types of transfers were compared directly: "S-->S," early embryonic nuclei (mostly in S-phase) were transferred to presumptive S-phase cytoplasts; "M-->MII," nocodazole-treated embryonic nuclei (most in M-phase) were transferred to MII-phase cytoplasts; and control (S-->MII), conventional nuclear transfer of fusion and activation simultaneously. The results showed that fusion and recovery rates did not differ among the three groups. However, after 6 days of in vivo culture, the morula and blastocyst formation rate was significantly higher for the M-->MII combination than for the control (28.3% vs. 8.1%, P < 0.05), while no significant differences in developmental rate were observed between S-->S and M-->MII, and between S-->S and control, though developmental rate was also increased for S-->S compared to control (20.9% vs. 8.1%, P > 0.05). Transfer of blastocysts derived from M-->MII or S-->S nuclear cytoplasmic reconstitution to synchronized recipient ewes resulted in the birth of lambs. These data suggest that in vitro matured oocytes can support full-term development of nuclear transplant sheep embryos when the cell cycle of nucleus and cytoplasm is coordinated, and that M-->MII nuclear transfer might be an efficient and simple way to improve the developmental competence of the reconstituted embryos.

Role of secreted proteins and gonadotrophins in promoting full maturation of porcine oocytes in vitro

Experiments were designed to identify the extent to which follicle cells and hormones contribute to the developmental competence of porcine oocytes matured in vitro. Oocyte-cumulus complexes were collected from ovaries by dissection and cultured in 2 ml of TCM199-based medium in 5% CO2 in humidified air at 38.5 degrees C. This basic maturation system was supplemented, for either the first 24 hr only or for the 48-hr culture period, with 1) everted follicle shell alone, 2) gonadotrophic hormones alone, or 3) both follicle shells and hormones. The effect of these treatments was evaluated on 1) meiotic maturation rates, 2) the capacity of matured eggs to undergo activation and early cleavage, and 3) changes to the profile of proteins secreted into the culture medium. The results showed that 1) supplementation with either follicle shell or hormones alone increased the rates of meiotic maturation over the nonsupplemented control group, and 2) combined follicle shell and hormonal supplementation yielded the highest rates for maturation, activation, and cleavage but only when hormonal supplementation was removed after the first 24 hr of culture. Proteins of 30, 37, 45, and 46 kD, but of unknown function, were secreted during the first 24 hr into the culture medium in groups supplemented with follicle shells. The addition of hormones did not affect this pattern of secreted proteins. It is possible that some secreted proteins may act to facilitate full maturation of pig oocytes.

[Pharmacological study on the compatibility of cortex Cinnamomi with Halloysitum Rubrum]

The decoction of Cortex Cinnamomi (CC, 1 g/kg p.o.) and Halloysitum Rubrum (HR, 3 g/kg p.o.) or the combination of the two drugs (4 g/kg p.o., CC 1 g/kg, HR 3 g/kg) could antagonize the diarrhea caused by p.o. water ex tract of Radix et Rhizoma Rhei in mice; and inhibit the platelet aggregation induced by ADP in vitro. Meanwhile, the effect of the combination of the two drugs was not different from that of each single one. In addition, CC was able to inhibit the spontaneous movement of intestine in situ and showed an analgesic effect (hot-plate method) in mice; HR was ineffective in these aspects and did not reduce the effect of CC. CC(20 g/kg p.o., i.p. or i.v.) exhibited very strong toxicity in mice, while HR(60 g/kg p.o., i.p. or i.v.) was nontoxic. When the two drugs were used together, the toxicity was markedly reduced.

[Spectrophotometry analysis of berberine chloride in xianglian jiaowan]

After isolation of column chromatograph with organic solvent containing acid water, the content of berberine chloride in Xianglian Jiaowan (a Chinese drug) is determined by spectrophotometry. The analysis method is specific, sensitive and accurate, recovery is 99.8% and RSD is o.78%.

Mutant human protein disulfide isomerase assists protein folding in a chaperone-like fashion

Human protein disulfide isomerase with an extra 10 amino acid residues of AEITRIDPAM at the N-terminal was expressed in E. coli as a soluble protein comprising 20% of total cell proteins, and was purified to near homogeneity through one step of DEAE-Sephacel chromatography. The mutant enzyme, which had the same CD spectrum and comparable disulfide isomerase and thiol-protein oxidoreductase activities with that of the wild type human and bovine protein disulfide isomerases, also showed chaperone-like activity in stimulating the refolding of proteins containing no disulfide bond. The overall yield of the active product is about 20 mg 1-1 culture.

Differences in depression and self-esteem reported by learning disabled and behavior disordered middle school students

Although generalizations from research are helpful in guiding problem identification and interventions in a school setting, characteristics of specific groups must not be overlooked if all students are to be served effectively. Differences in the areas of self-reported self-esteem and depression are frequently pertinent to decisions and recommendations educational professionals are called on to make. The current study examined differences in the level of self-reported self-esteem and depression between learning disabled and behavior disordered middle school students. Sixty-one participants completed the Coopersmith Self-Esteem Inventory (CSEI) and the Children's Depression Inventory (CDI). Similarities and differences between learning disabled and behavior disordered students were identified.

[Studies on Kochiae Fructus. I. Antipruritogenic effect of 70% ethanol extract from kochiae fructus and its active component]

The antipruritogenic effect of the 70% ethanol extract obtained from Kochiae Fructus (fruits of Kochia scoparia) and its active components were investigated on a compound 48/80-induced pruritogenic model in male ddY strain mice. The extract (200, 500 mg/kg, p.o.) inhibited the scratching behavior as a pruritogenic indicator. Oleanolic acid oligoglycoside, momordin Ic, isolated from the extract also exhibited the inhibition. These results suggest that Kochiae Fructus could be used as an antipruritogenic agent and its inhibitory effect may be partially attributed to momordin Ic.

Construction of adenovirus vectors through Cre-lox recombination

Two barriers prevent adenovirus-based vectors from having wide application. One is the difficulty of making new adenoviruses, and the second is the strong immunological reaction to viral proteins. Here we describe uses of Cre-lox recombination to overcome these problems. First, we demonstrate a simple method for constructing E1-substituted adenoviruses. Second, we demonstrate a method to construct adenovirus vectors carrying recombinant genes in place of all of the viral genes, so-called gutless adenovirus vectors. The pivotal feature in each method is the use of a negatively selected adenovirus named psi5. We engineered a cis-acting selection into psi5 by flanking its packaging site with loxP sites. When psi5 was grown in cells making a high level of Cre recombinase, the packaging site was deleted by recombination and the yield of psi5 was reduced to 5% of the wild-type level. To make a new E1-substituted virus, we used psi5 as a donor virus and recombined it with a shuttle vector via a loxP site. The resulting recombinant virus has a single loxP site next to the packaging site and therefore outgrows psi5 in the presence of Cre recombinase. To make a gutless virus, we used psi5 as a helper virus. The only viral sequences included in the gutless vector are those needed in cis for its replication and packaging. We found that a loxP site next to the packaging site of the gutless virus was necessary to neutralize homologous recombination between psi5 and the gutless viruses within their packaging domains.

Anti-allergic effect of an aqueous extract of wu-hu-tang

Wu-Hu-Tang (WHT), a Chinese formulation which consists of seven crude drugs, has been used for the treatment of asthma for hundreds of years. In this paper, an investigation on the anti-allergic activity of an aqueous extract of WHT was undertaken to find the pharmacological basis for the ethnomedical use of the formulation. WHT produced a significant inhibition on the homologous passive cutaneous anaphylaxis (PCA) in rats and the heterologous PCA in mice, decreased the degranulation of mast cells of calvarial periosteum in rats, inhibited the release of anaphylactic mediators from sensitized lung tissues of guinea pigs and the contraction of isolated guinea pigs ileum induced by histamine. These results indicated that the therapeutic activity of WHT for asthma may be related to its inhibitory effects on immediate hypersensitivity.

Characterization and expression of vascular endothelial growth factor (VEGF) in the ovine corpus luteum

The corpus luteum undergoes tremendous growth, development and regression each oestrous or menstrual cycle. These changes are reflected by equally impressive growth and regression of the luteal vasculature. We have previously shown that angiogenic factors from corpora lutea are primarily heparin binding and that one of these factors is similar to vascular endothelial growth factor (VEGF). In an effort to identify this factor, and to define its role in luteal vascular development, the cDNA for the coding region of ovine VEGF was sequenced and a sensitive RNase protection assay was developed to quantitate mRNA encoding VEGF in luteal tissues from ewes in the early (days 2-4), mid- (day 8) and late (days 14-15) stages of the oestrous cycle. In addition, an N-terminal peptide was synthesized from the translated ovine cDNA sequence for VEGF and an antiserum was raised against this peptide for use in western immunoblotting procedures. Nested reverse transcriptase (RT)-PCR of RNA from ovine corpora lutea resulted in three products that correspond in size to the alternatively spliced variants of VEGF (VEGF120, VEGF164, and VEGF188) predicted from other species. The RNase protection assay revealed that the proportion of mRNA encoding VEGF was 2- to 3-fold greater on days 2-4 than on day 8 or days 14-15. Densitometric analysis of gels from the RNase protection assay showed that VEGF120 represented approximately one third of the total mRNA encoding VEGF in the corpus luteum and that this proportion did not vary with stage of the oestrous cycle. SDS-PAGE and western immunoblot analysis of a homogenate from corpora lutea showed a single 18 kDa protein. These data demonstrate that VEGF is expressed in luteal tissue throughout the ovine oestrous cycle and that expression of mRNA encoding VEGF is upregulated during the period of rapid luteal development, when luteal vascular growth is at its maximum.

Characteristic, activity and conformational studies of [A6-Ser, A11-Ser]-insulin

Met-[A6-Ser, A11-Ser]-human proinsulin (Mut-HPI) was prepared in the same way as described previously for Met-human proinsulin (Met-HPI). After trypsin and carboxypeptidase B cleavage and DEAE-Sephadex A25 separation, Met-[A6-Ser, A11-Ser]-human insulin (Mut-HI) and Met-human insulin (Met-HI) were obtained. Their amino-acid compositions are in a good agreement with those expected. Mut-HI keeps full immuno activity, but loses almost all of its receptor binding activity with Met-HI as the control. Some physico-chemical behaviors of Mut-HI have changed to a certain extent. CD studies of mutant insulin demonstrates that the conformation of Met-HI is very similar to that of HI, while that of Mut-HI has altered slightly. The most important observation is that the binding ability of Mut-HI to the receptor has decreased abruptly. These results suggest that though the intra-A chain disulfide bond is deleted, the other two inter-chain disulfide bonds are still correctly paired, and that the intra-A chain disulfide bond is essential for insulin displaying its biological activity.

Transcription of c-mos protooncogene in the pig involves both tissue-specific promoters and alternative polyadenylation sites

The function of the c-mos gene has been intensively studied, but its role in the mammal is still a subject for debate. For this reason, and because the gene is regulated posttranscriptionally, further study of the gene from other mammalian species is timely. The pig c-mos gene has been cloned, and the genomic sequence is presented here. The gene has no introns and shows close similarity to human and monkey genes, with striking sequence similarities in both the 5' and 3' flanking regions. The significance of this similarity in the context of gene regulation is discussed. c-mos expression was found to be restricted to gonadal tissues in the pig. The major start sites for transcription initiation in ovary and testis were identified by primer extension and found to be distinct, as in the mouse. Within the ovary, expression is confined to oocytes. Messenger RNA is synthesized in growing oocytes, and remains stable during oocyte maturation, but begins to be degraded in electrically stimulated eggs. Unexpectedly, RNase protection assays revealed that the 3' ends of transcripts in the pig ovary are heterogeneous, and this, together with the identification of three distinct cDNA clones, shows that multiple polyadenylation sites are used. The significance of these transcripts in terms of translational control is discussed.