[The expression of API2-MALT1 fusion gene and its influence on the cellular apoptosis and proliferation in gastrointestinal MALT lymphoma]

OBJECTIVE

To investigate the expression of API2-MALT1 fusion gene mRNA and its effect on protein of API2, Caspase3 and Ki67 in gastrointestinal MALT lymphoma (Extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue).

METHODS

The mRNA of API2-MALT1 fusion transcript was assayed in 33 archival cases of gastrointestinal MALT lymphoma by RT-PCR and nested PCR. According to the expression of API2-MALT1 mRNA or not, 33 cases of MALT lymphoma were divided into two groups. Ki67, API2 and Caspase3 were detected by immunohistochemical technique and analyzed by the microsoft Image-Pro plus.

RESULTS

API2-MALT1 fusion gene mRNA was found in 16 of specimens with gastrointestinal MALT lymphoma. The expression rate was 48.4%. The average area (21177.30 +/- 6171.72) micron 2 and single cell average area (29.81 +/- 7.40) micron 2 of API2 were decreased in the group with the expression of API2-MALT1 mRNA, compared with those in the group without the expression of API2-MALT1 mRNA [(34325.65 +/- 6577.00) micron 2, (37.84 +/- 8.55) micron 2]. The integrated optical density(IOD) of API2 showed no significant difference between the two groups, neither did the expression of Ki67 and Caspase3.

CONCLUSION

The expression of API2-MALT1 is related to the down-regulated expression of protein of API2, its effect on apoptosis of MALT lymphoma remains to be detected further. The expression of API2-MALT1 mRNA is unrelated to the cellular proliferation.

Probiotics inhibit TNF-α-induced interleukin-8 secretion of HT29 cells

AIM: To study the effect of probiotics on interleukin-8 secretion in intestinal epithelia when stimulated by proinflammatory cytokines.

METHODS: Colonic adenocarcinoma HT29 cells were cultured and divided into four groups: control, TNF-α (group T in short), bifidobacterium (group B), lactobacillus (group L). B. Longum and L. bulgaricus were suspended in culture medium with a concentration of 1 × 10⁸ cfu/ml and added into 24 wells respectively. One hour later TNF-α (10 ng/ml) was added into each well of groups T, B, L. The supernatants were collected and measured for IL-8 after 3 hours, nuclear factor-kB (NF-κB) p65 was also examined by Western blotting.

RESULTS: There was less interleukin-8 secretion in HT29 cells when preincubated with B. Longum or L. bulgaricus compared with group T. Less p65 appeared in nuclei in groups B and L compared with group T, as detected by Western blot.

CONCLUSION: Probiotics can suppress interleukin-8 secretion in intestinal epithelia when stimulated by proinflammatory cytokines, which is most likely mediated by NF-κB.

Development of an MHC-class I peptide selection assay combining nanoparticle technology and matrix-assisted laser desorption/ionisation mass spectrometry

Human leukocyte antigen (HLA)-bound peptides are central for recognition of infected/transformed cells by T cells, and have formed the basis for many immunotherapy strategies. Epitopes from a given protein sequence (e.g. from viral proteins or oncoproteins) can be predicted by algorithms, as individual HLA receptors bind peptides through defined binding motifs. Peptides with the highest predicted binding score are then normally tested for their binding ability in binding assays. However, with the assays already established, only one peptide can be tested for binding per assay. This is certainly not a reflection of the in vivo situation, where several peptides generated via the major histocompatability complex (MHC)-class I processing pathway compete for HLA-receptor binding. Here, we describe the development of a method that can mimic the competition between multiple peptides for binding to a single HLA receptor molecule. We used silica nanoparticles with immobilised HLA-A2 complexes to screen HLA-A2 binder-peptides out of a known peptide mixture. The washed beads were analysed for selectively bound peptides by matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry. The advantage of the system is that the bound peptides can be unambiguously identified without any prior modification (e.g. radioactive or fluorescence labelling), even from complex peptide mixtures.

[The preventive and therapeutic effects of low molecular weight heparin on DSS-induced colitis in mice]

OBJECTIVE

To evaluate the preventive and therapeutic effects of low molecular weight heparin (LMWH) on dextran sulphate sodium (DSS)-induced colitis in mice.

METHODS

Twenty normal mice were randomized into two groups: 10 mice of the prevention group received DSS per os and LMWH by sub-cutaneous injection for 7 days; 10 mice as controls received DSS per os and sub-cutaneous normal saline for 7 days. Another 20 mice with DSS-induced colitis were randomized into two groups: the treatment group received sub-cutaneous injection of LMWH and the control group received subcutaneous injection of normal saline for 7 days. The preventive and therapeutic effects of LMWH were assessed by disease activity index (DAI), histologic score and MSB fibrin staining to identify microvascular thrombus.

RESULTS

The DAI, rectal and transverse histological scores of the prevention group compared with those of the control group were 2.40 vs 2.52 (P > 0.05), 1.65 vs 1.85 (P > 0.05), 1.55 vs 1.72 (P > 0.05), respectively. Microvascular thrombi in the prevention group decrease significantly as compared with the control; microvascular thrombi were positive in 6 of 10 controls, but only one was positive in the prevention group, P = 0.029. The DAI, rectal and transverse histological scores in the treatment group compared with those of the control were 0.42 vs 0.44 (P > 0.05), 1.36 vs 1.75(P < 0.05), 1.30 vs 1.65(P < 0.05), respectively. Microvascular thrombi were positive in 3 of 10 controls, and one microvascular thromous was positive in the treatment group, P = 0.291.

CONCLUSION

LMWH could effectively prevent microvascular thrombosis and inhibit colonic and rectal inflammation in the mice with DSS-induced colitis. These animal experimental results suggested that LMWH might also be used effectively in ulcerative colitis.

Age-associated accumulation of CMV-specific CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1)

Large clonal expansions of peripheral CD8+ T cells carrying receptors for single epitopes of CMV and EBV are common in the elderly and may be associated with an immune risk phenotype predicting mortality. Here we show that the frequency of CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1), a marker of cells unable to undergo further clonal expansion, was markedly elevated in CD8+ T cells from old donors. Moreover, tetramer staining revealed that the elevated frequency of CMV-specific CD8+ T cells in the elderly was due to an accumulation of cells bearing this dominant negative receptor. The fraction of CMV-specific T cells able to secrete interferon-gamma after specific antigenic stimulation was significantly lower in the elderly than in the young, although the total number of functional cells was comparable. Therefore, the majority of the clonally expanded virus-specific CD8+ cells in the elderly was dysfunctional. Thus, T cell responses are altered in the aged by an accumulation of replicatively senescent dysfunctional T cells carrying receptors for persistent herpes viruses. The presence of clonal expansions of such virus-specific cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious disease in the elderly.

[Investigation of the effect of Na-butyrate on TNBS induced rat colitis]

OBJECTIVE

To observe the effect of Na-butyrate on trinitrobenzene sulfonic acid (TNBS) induced rat colitis and discuss its mechanism.

METHODS

0.85 ml of 50% ethanol enema containing 30 mg TNBS was instillated into rat colon to produce distal colitis. On the 5th day after TNBS enema, the rats were divided into 3 groups and were given respectively 100 mmol/L Na-butyrate, 100 mg/kg SASP or 0.9% saline enema daily. On the 19th day, macroscopical, histological injury scores of colonic mucosa and tissue myeloperoxidase (MPO) activity were evaluated, and the mitotic index in Na-butyrate group was compared with that in SASP group.

RESULTS

Diarrhea was apparently improved, weight gain was not apparently different, the scores of macroscopical and histological injury and MPO activity decreased in the SASP group and the Na-butyrate group, compared with the control (P < 0.05). However, there was not obvious difference between the Na-butyrate group and SASP group (P > 0.05). Mitotic index in Na-butyrate group was higher than that in SASP group (P < 0.05).

CONCLUSION

Na-butyrate enema can expedite the restoration of the experimental colitis, and its therapeutic effect is as good as that of SASP.

Large numbers of dysfunctional CD8+ T lymphocytes bearing receptors for a single dominant CMV epitope in the very old

Longitudinal studies suggest that a set of immune parameters including high percentages of peripheral CD8+, CD28-, CD57+ T lymphocytes, low CD4 and B cell counts, and poor T cell proliferative responses to mitogens is associated with decreased remaining longevity in the free-living very elderly (> 85 years). This combination of immune parameters was also significantly associated with an inverted CD4/CD8 ratio and cytomegalovirus seropositivity. Here, using tetramer technology, we show markedly increased numbers of CD8+ T cells bearing receptors for one single CMV epitope in the very elderly. Moreover, the fraction of these tetramer-reactive cells secreting interferon-gamma after specific antigenic stimulation was significantly lower in the old than in the young, as was the percentage of CD28-positive cells in this population. Therefore, we conclude that marked expansions of CMV-specific CD8+ T cells have occurred and that the obsession of a large fraction of the entire CD8+ T cell subset with one single viral epitope may contribute to the increased incidence of infectious disease in the elderly by shrinking the T cell repertoire available for responses to other antigens.

[Effects of NaBT and NSAIDs on colorectal adenoma-carcinoma cells]

OBJECTIVE

We investigated the primary adenoma cells and HT-29 cells in an attempt to know whether NaBT and two NSAIDs (aspirin and NS-398) could be used as effective adjuvant for reducing cell proliferation, and to explore the possible mechanisms therein involved.

METHODS

MTT was employed in detecting the anti-proliferative effects on both adenoma and HT-29 culture cells.

RESULTS

Both butyrate and NSAIDs could inhibit the proliferation of cells. The effects of the NSAIDs could be synergistically strengthened by combining with butyrate.

CONCLUSION

NaBT and the two NSAIDs could inhibit the cell proliferation when used separately, and a combination of butyrate with aspirin or NS-398 could enhance the inhibitory effects.

[The effects of nuclear factor-kappa B p65 antisense oligonucleotides on expression of proinflammatory cytokines in lamina propria mononuclear cells from patients with ulcerative colitis]

To investigate if nuclear factor-kappa B (NF-kappa B) p65 antisense oligonucleotides might affect the expression of NF-kappa B p65 and cytokines in lamina propria mononuclear cells(LPMC) from patients with ulcerative colitis (UC). LPMC were isolated from intestinal mucosal biopsy specimens from 3 patients with UC, and cultured with or without NF-kappa B p65 antisense oligonucleotides (5'-GGAACAGTTCGTCCTATGG-3'), missense oligonucleotides (5'-GGAACAGTTCGTCTATGG-3') and dexamethasone. NF-kappa B p65 expression was determined by western blot analysis. The expression of cytokine mRNA was studied by reversal transcription-polymerase chain reaction (RT-PCR). The cytokine levels were measured by enzyme linked immunosorbent assay. The results showed that NF-kappa B p65 antisense oligonucleotides resulted in down-regulation of NF-kappa B p65 expression, blocked the expression of IL-1 beta mRNA and IL-8 mRNA, and strikingly reduced the production of IL-1 beta and IL-8, and these effects were greater than those of dexamethasone in cultured LPMC from patients with UC(P < 0.05). Therefore, the application of NF-kappa B p65 antisense oligonucleotides may serve as a novel molecular approach for the treatment of patients with UC.

[The early diagnosis and treatment of gastric mucosa-associated lymphoma]

OBJECTIVE

To determine the general markers for the diagnosis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and select optimal cases to be interfered in early stage.

METHODS

To investigate the changes of histology, Ki-67 expression, monoclonality of IgH gene rearrangement in gastric lymphoid hyperplasia (GLH) cases before and after Helicobacter pylori (Hp) eradication treatment. Histological changes were classified according to Isaacson's criteria of GLH; L26, UCHL-1, anti-Kappa, anti-Lambda and Ki-67 were applied for immunohistochemical staining; semi-nest PCR was used to detect IgH gene rearrangement.

RESULTS

Thirty-one cases of GLH with predominant chronic gastritis and gastric ulcer were studied. The ratio of male to female in the 31 cases was 1.8 and the mean course 6.8 years. Twenty-nine cases had Hp infection. Most of the cases belonged to histological grade II and III. Only 1 case had lambda light chain restriction and 10 cases had monoclonal IgH gene rearrangement. Expression of Ki-67 and monoclonal IgH gene rearrangement were significantly increased with the crescendo of lymphoid hyperplasia grading (P < 0.05). 28 cases were given antibiotics with eradication of Hp in 24 cases and 2 cases had to be given another course of treatment. These cases were followed-up on average for 4.6 months. 18 cases showed complete regression both histologically and endoscopically, 4 cases partial regression and 6 cases no change. Four cases with histological grade II, III had the decrease of expression of Ki-67 and reversed to polyclonal IgH gene rearrangement, while there was no change in 4 cases with histological grade IV.

CONCLUSIONS

General considerations of histology, expression of Ki-67 and combined clonality of IgH gene rearrangement help to screen cases which need intervention early and make a diagnosis of gastric MALT lymphoma in early stage. Monoclonal IgH gene rearrangement in cases with histological grade III or IV appears to carry more clinical significance.

An age-related increase in the number of CD8+ T cells carrying receptors for an immunodominant Epstein-Barr virus (EBV) epitope is counteracted by a decreased frequency of their antigen-specific responsiveness

The aim of this study was to provide a basis for investigating the effects of one very common environmental factor, Epstein-Barr virus (EBV), on age-related changes in the immune system. To this end, the frequency of CD8(+) T cells carrying receptors for an immunodominant EBV lytic epitope was assessed by direct staining with HLA-peptide tetrameric complexes in 19 very old (>87 years) and 12 young (20-40 years) EBV carriers. The frequency of EBV-tetramer-positive cells within the CD8(+) subset was significantly greater in the old compared to the young group (P=0.001). However, the frequency of EBV antigen-specific IFN-gamma producing T cells, as determined by ELISPOT, was significantly lower in the old (P=0.001). Therefore, the absolute number of functional EBV-specific T cells in the elderly and the young was probably similar. These data suggest CD8 clonal expansions in the elderly, resulting in an accumulation of dysfunctional EBV-specific cells which possibly fill the 'immunological space' and could lead to a shrinking of the T cell repertoire for other novel antigens. This may help to explain the increased incidence and case-fatality caused by viruses and intracellular pathogens in the elderly.

[Interleukin 18 expression in colon cancer and adenoma]

OBJECTIVE

To investigate the expression of interleukin 18 in mucosa of colon cancer and adenoma.

METHODS

Expression of interleukin 18 was measured with immunohistochemical staining.

RESULTS

The expression rates of IL-18 in colon cancer, adenoma and relative normal mucosa were 78.8%, 100% and 100%, respectively (P > 0.05). In the case of colon cancer, the higher the cancer was differentiated, the higher the IL-18 expression level was observed (P < 0.05). In the case of colon adenoma, no significant relation was noted between the grade of dysplasia and the expression of IL-18 (P > 0.05).

CONCLUSION

In colon adenoma, all mucosae express IL-18. But in colon cancer, IL-18 expression is decreased or absent, and the lower the cancer is differentiated, the lower will be the level of IL-18 expression in epithelium.

Pathways to a robust immune response in the elderly

Circumstantial evidence suggests that infectious disease is the major cause of morbidity and mortality in the elderly, and immune-system dysfunction may contribute to this finding. Because innate and humoral immunity seem to be relatively unaffected by aging and because the T-cell compartment shows marked age-associated alterations, this article focuses on the association between T cells and aging. Longitudinal studies suggest that immune parameters, which predominantly are related to T cells, can be clustered to yield an IRP that is predictive of mortality in the elderly. Determining the IRP also may be helpful in younger individuals, particularly those under chronic antigenic stress (eg, patients with cancer or chronic infections) who experience premature aging of the immune system. Some changes in T cells can be modeled in clonal cultures in vitro to discover new biomarkers of immune aging. These biomarkers, which need to be validated in vivo, could be used to refine IRP. Interventions to selectively target changes that are identified as part of IRP may improve the health and quality of life of the elderly, reduce healthcare costs, and avoid potential unwanted side effects of global intervention approaches, such as triggering or exacerbating autoimmunity and inflammation.

The abl/bcr gene product as a novel leukemia-specific antigen: peptides spanning the fusion region of abl/bcr can be recognized by both CD4+ and CD8+ T lymphocytes

Chronic myelogenous leukemia (CML) is characterized by a reciprocal translocation leading to the Philadelphia chromosome. Two fusion genes are created by this translocation: bcr/abl and abl/bcr. The fusion regions of both translocation products are unique and strictly limited to leukemia cells, giving rise to potential tumor-specific antigens. Although several studies on the immunogenicity of peptides spanning the bcr/abl fusion region have been reported, little is known about the corresponding reciprocal translocation product abl/bcr. Here we report that synthetic peptides representing the fusion region of the abl/bcr forms a1bb3 and a1bb4 can be specifically recognized by HLA-A2-restricted cytotoxic T lymphocytes from healthy donors. Furthermore, HLA-matched a1bb3-expressing CML cells can be recognized by a1bb3-specific HLA-A2-restricted T cells, indicating natural processing and presentation of abl/bcr protein by leukemia cells. Moreover, a 19-mer peptide encompassing this class I-binding sequence also elicited a1bb3-specific class II-restricted T-cell responses. Thus, both class I- and class II-restricted T-cell responses can be stimulated in healthy donors by abl/bcr peptides in vitro. Because abl/bcr is expressed in the majority of CML patients, it may represent a highly leukemia-specific antigen with potential use in immunotherapy.

Compromised interferon gamma (IFN-gamma) production in the elderly to both acute and latent viral antigen stimulation: contribution to the immune risk phenotype?

The elderly suffer from an increased incidence of infectious disease, accompanied by increased morbidity and mortality. Interferon-gamma plays an important role in defense against intracellular pathogens such as mycobacteria and viruses. A reduced capacity to produce this cytokine in the elderly, as demonstrated by our findings of significant decreases in IFN-gamma production in vitro on stimulation with bacterial products (LPS) or viral antigens (influenza vaccine), might therefore contribute to disease susceptibility. Moreover, accumulating data suggest that persistent infection with EBV and particularly CMV impacts upon the immune system in aging and may contribute to the immune risk phenotype (IRP), which predicts remaining longevity in the very elderly. Using tetramer technology and IFN-gamma ELISPOT assays, we found that the commonly-observed clonal expansions of CD8+ T-cells in the elderly were for the most part poorly-functional CMV- and EBV-specific cells, expressing little CD28. The resulting accumulation of dysfunctional cells may lead to a reduction of the repertoire of functional T-cells available for responses to novel antigens. Further longitudinal studies are needed to demonstrate whether cytokines such as IFN-g are also part of the IRP. Improving the definition of the IRP will help to understand and thus prevent or reverse age-associated immune dysfunction.

Differentiation between intestinal tuberculosis and Crohn's disease in endoscopic biopsy specimens by polymerase chain reaction

OBJECTIVES

It is difficult to differentiate intestinal tuberculosis from Crohn's disease because of similar clinical, pathological, radiological, and endoscopic findings. The purpose of this study was to investigate the value of polymerase chain reaction (PCR) assay in the differentiation intestinal tuberculosis from Crohn's disease, and compare the histopathological features of endoscopic biopsy of the two disorders.

METHODS

A total of 39 endoscopic biopsy specimens from patients with intestinal tuberculosis and 30 specimens from patients with Crohn's disease were subjected to pathological analysis retrospectively, Ziehl-Neelsen stain, and PCR assay.

RESULTS

Except for granuloma with caseation and confluence, which was the characteristic of intestinal tuberculosis, other pathological features of intestinal tuberculosis and Crohn's disease were very similar or were difficult to find in endoscopic biopsy specimens. The positivity rate by PCR in 39 intestinal tuberculosis specimens was 64.1% (25/39), but was zero by PCR in 30 Crohn's disease specimens. Moreover, in the tissues of intestinal tuberculosis with granulomas similar to those of Crohn's disease, there were 71.4% (10/14) positive by PCR, and there were 61.1% (11/18) positive in intestinal tuberculosis tissues without granulomas.

CONCLUSIONS

Biopsy is of limited diagnostic value in the differentiation intestinal tuberculosis from Crohn's disease, and PCR is valuable in the differentiation between intestinal tuberculosis and Crohn's disease.

Experimental and numerical studies of noise-induced coherent patterns in a subexcitable system

A subexcitable medium of Belousov-Zhabotinsky (BZ) reaction subjected to external Gaussian white noise is studied in experiments and numerical simulations. We observe that at an optimal level of noise the wave sources of excited traveling waves become synchronous, as though there exists a long distance spatial correlation. The synchronous behavior fades if the noise level becomes larger or smaller. Numerical simulations confirm the experimental findings, and point out that the best synchronous behavior takes place when the signal-to-noise ratio of waves becomes largest.

[Activation of nuclear factor-kappaB and its relationship with cytokine gene expression in colonic mucosa of ulcerative colitis patients]

OBJECTIVE

To investigate the activation of nuclear factor-kappaB (NF-kappaB) and its relationship with expression of cytokine mRNA in intestinal mucosal biopsy specimens from patients with ulcerative colitis (UC).

METHODS

31 cases with UC were included in the study. 17 cases received sulfasalazine (SASP) or SASP and glucocorticoid treatment. 14 cases did not receive any medication related with UC. Normal mucosa from 11 colon cancer cases served as control. Ten pieces of intestinal mucosal biopsy specimens were obtained from each patient. NF-kappaB DNA binding activity was evaluated with electrophoretic mobility shift assay (EMSA). Expression of cytokine mRNA were studied with reversal tanscription-polymerase chain reaction (RT-PCR).

RESULTS

(1) The expression of IL-1beta mRNA and IL-8 mRNA was increased significantly in patients with UC, as compared with that in the control specimens (P < 0.05) and had a significant positive correlation with NF-kappaB DNA binding activity (r = 0.8363, P < 0.05; r = 0.6024, P < 0.05, respectively). (2) Glucocorticoids and SASP strongly inhibited NF-kappaB activation and signficantly decreased the expression of IL-1beta mRNA and IL-8 mRNA.

CONCLUSIONS

NF-kappaB is a major and essential factor in regulating the expression of cytokine and plays a fundamental role in the pathogenesis of UC. SASP and glucocorticoids decrease cytokine expression via inhibition of NF-kappaB activation.

[Activation of nuclear factor-kappaB and effects of anti-inflammatory treatment thereon in intestinal mucosa of patients with ulcerative colitis]

OBJECTIVE

To investigate the activation and expression of nuclear factor-kappaB (NF-kappaB) and effects of anti-inflammatory treatment on NF-kappaB in the intestinal mucosa of patients with ulcerative colitis (UC).

METHODS

Ten pieces of colon mucosal biopsy specimens were obtained from 31 cases with UC, 17 of which received sulphasalazine (SASP) or SASP plus glucocorticoid and 14 of which received no medication. Samples of normal mucosa around the lesion taken from 11 patients with colon cancer were used as controls. NF-kappaB DNA binding activity was evaluated by electrophoretic mobility shift assay. NF-kappaB p65 expression was determined by Western blot analysis and immunohistochemical staining with a NF-kappaB p65 antibody. The type of cells containing activated NF-kappaBp65 was identified by double immunofluorescence confocal laser scanning microscopy.

RESULTS

The expression of NF-kappaB p65 and NF-kappaB DNA binding activity were significantly higher in patients with UC than in the control (P < 0.05), and were correlated with the degree of inflammation. The NF-kappaB expression was significantly stronger in the nuclei than in the cytoplasm in patients with UC without pharmacotherapy. The NF-kappaB expression in nuclei was significantly stronger in the group without pharmacotherapy than in the group with pharmacotherapy (P < 0.05). Only a few NF-kappaB p65 positive cells were seen in the controls. NF-kappaBp65 expression was found in all major subsets of mononuclear cells, including macrophages, B lymphocytes, T lymphocytes, and cryptal epithelial cells.

CONCLUSION

The increased activation of NF-kappaB and increased expression of NF-kappaB may be involved in the pathogenesis of UC. Glucocorticoids and SASP strongly inhibited NF-kappaB activation and expression. The inhibition of NF-kappaB activation may be a central part of the anti-inflammatory action of glucocorticoids and SASP, which might represent an important pharmacological mechanism in treatment of patients with UC. NF-kappaB will be an important target for cytokine-based therapy of UC.

[The effects of butyrates and non-steroidal anti-inflammatory agents on HT-29 colonic carcinoma cells]

OBJECTIVE

Adenocarcinoma cells HT-29 were used to investigate whether butyrates and non-steroidal anti-inflammatory agents (NSAIDs, aspirin and NS-398) would be effective adjuvants for inducing apoptosis and to probe its possible mechanisms.

METHODS

Prostaglandin E(2) (PGE(2)) isolated from HT-29 cell culture supernants was investigated with ELISA. Flow cytometry was used for estimating apoptosis. The morphology of apoptotic cells was investigated by means of electron microscopy.

RESULTS

Butyrates could stimulate the secretion of PGE(2). In contrast, NSAIDs inhibited it to a level below 30 ng/L. Both butyrates and NSAIDs could induce apoptosis. The effects showed the obvious tendency of time- and concentration-dependency (P < 0.05). Combination with two drugs could enhance the above effects.

CONCLUSIONS

Butyrates and NSAIDs could induce apoptosis individually. Combination with the two drugs could enhance the above effects by down-regulating cyclooxygenase-2 expression.

Basic biology and clinical impact of immunosenescence

Immunosenescence is an age-associated decline of immunity involving multiorgan changes. As the mean age of the population increases, an increase of diverse pathologies associated with immunosenescence has been observed in the developed countries. Age-related changes in the immune system contribute to the increased incidence and severity of infectious diseases and possibly cancer in the elderly. Moreover, in young individuals chronic activation of the immune system (as occurs in autoimmune diseases, cancer, HIV infection and other chronic infections) induces changes in the immune response that parallel those observed in elderly individuals. An interdisciplinary approach to immunosenescence including investigation of the molecular and cellular mechanisms and clinical aspects is being utilised by the EU program "Immunology and Ageing in Europe" (ImAginE, QLK6-CT-1999-02031), the second major international conference of which took place in Córdoba, Spain, 22-26th March, 2001). We briefly summarise some of the highlights of the meeting here, and bring together in this special issue a collection of peer-reviewed papers reflecting the broad approach to immunosenescence currently being applied.

[The growth inhibition of colorectal adenoma cells by sulindac and its mechanisms]

OBJECTIVE

This study was conducted to assess the growth inhibition of colorectal adenoma cells by sulindac and identify the possible mechanisms.

METHODS

The colorectal adenoma cells from human sporadic adenomatous polyps were cultured, and then treated with sulindac. The cell viability was examined by MTT colorimetric assay; the S-phase fraction and the percentage of apoptosis were measured by flow cytometry.

RESULTS

Following sulindac treatment at different concentrations for 24, 48 and 72 hours, reduction of the cell viability was time- and dose-dependent. After 48-hour-treatment, S-phase fraction was decreased and the percentage of apoptosis was increased; both indexes of all groups except 0.3 mmol/L group were different from those of controls (P < 0.05).

CONCLUSION

These data suggested that sulindac could inhibit the growth of the colorectal adenoma cells, and its mechanisms might be related to suppressing proliferation and inducing apoptosis.

[The primary culture methods of colorectal adenoma cells]

OBJECTIVE

To improve the primary cell culture methods of colorectal adenomas.

METHODS

The methods of the in vitro primary cell culture of colorectal adenomas, mainly the method for taking and preparing specimen, the methods of culture conditions and cells purification, were considered again and improved in this study.

RESULTS

Of the 32 cases, of polyp, 26 were successfully cultured and 6 failed. The culture lasted 5-23 days with 50%-95% viscosity of wells. By means of immuno-histochemical staining and electromicroscopy, the cultured cells were proved to be of epithelial origin.

CONCLUSION

The primary culture methods of adenoma cells have been improved, but further study on the serial transfer culture cell lines is most needed.

Microscopic self-organization in networks

We report our numerical studies on microscopic self-organization of a reaction system in three types of differently connected networks: a regular network, a small-world network, and a random network. Our simulation results show that the topology of the network has an important effect on the communication among reaction molecules, and plays an important role in microscopic self-organization. The correlation length among reacting molecules in a random or a small-world network is much shorter compared with that in a regular one. As a result, it is much easier to obtain microscopic self-organization in a small-world or a random network. We also observed a phase transition from a stochastic state to a synchronized state when we increased the randomness of a small-world network.

Dynamics of DNA-protein interaction deduced from in vitro DNA evolution

We report the first experimental study of the dynamics of in vitro evolution of DNA. Starting from a random pool of DNA sequences, we used cycles of selection (binding to the lac repressor protein), amplification, and mutations to evolve to a unique DNA sequence, the lac operator. Statistical analysis of the DNA sequences obtained during the cycles of evolution shows that the DNA bases are selected at different rates. The rates of selection provide a quantitative measure of the interaction of the DNA bases with the protein during the complex formation. A model reproduces the evolution dynamics of the DNA population but cannot give the fine structure of the DNA-protein interaction.

[Study on gastric motility and its relevant factors in type 2 diabetes]

OBJECTIVE

In this study radionuclide semi-liquid gastric emptying (GE) study was adopted to test the gastric motility in 129 patients with type 2 diabetes. Further study was made to explore the relationship between gastric motility disorder of diabetes and the influential factors.

METHODS

The variables to be measured and analyzed were age, BMI, duration of illness, level of glycemia, HbAlc, plasma insulin, motilin, gastrin, glucagon and Mg2+.

RESULTS

Of the 129 cases, 80 had delayed GE with an occurrence of 62.02%, and there was a close correlation between gastric motility disorder and the duration of illness, BMI, FPG, PPG, serum insulin, motilin levels and HbAlc as well.

CONCLUSION

These findings imply that gastric motility disorder of diabetes is influenced by multiple factors. The results also suggest that gastric motiligy disorder is much more common than expected, and radionuclide gastric emptying test is a useful aid for the early detection of this clinical entity.

[Study on the effect of COX-2's selective inhibitor on human colorectal adenoma cells proliferation]

OBJECTIVE

To investigate the mechanism of COX-2's selective inhibitor, NS-398, on human colorectal adenoma development.

METHODS

The human colorectal adenoma cells were isolated and cultured identified. The cell growth rates were assessed, when treated with NS-398, by using MTT method. Expression of COX-2 protein in human colorectal tumor was examined by immunohistochemistry.

RESULTS

23 of 30 colorectal adenomas were primary cultured successfully. NS-398 inhibited the proliferation of the cells in a dose- and time-dependent manner. COX-2 was overexpressed in colorectal adenoma(83.1%) and cancer(80.0%)compared with normal colon mucosa.

CONCLUSION

The key of the several culture conditions for the survival of human colorectal adenoma cells have been improved. Such as, best of the digestive time and number of cell. The cells can be inhibited by NS-398 with dose-dependent. Overexpression of COX-2 protein occurs early during colorectal carcinogenesis which contribute to tumour formation.

Reduction of the oxidative injury to the rabbits with established atherosclerosis by protein bound polysaccharide from Coriolus vesicolor

Recent evidence has emerged that macrophage glutathione (GSH) content and selenium dependent glutathione peroxidase (SeGSHPx) activity are inversely related to cell-mediated oxidation of LDL, and intervention means to enhance the macrophage GSH-SeGSHPx status may contribute to attenuation of the atherosclerotic process. Our previous works showed that protein bound polysaccharide (PSK) injected intraperitoneally could enhance SeGSHPx activity and mRNA content of mouse macrophages. The aim of the present study is to demonstrate whether PSK can reduce the oxidative injury to the established atherosclerotic rabbits. Using the established atherosclerotic rabbit model, we studied the effect of PSK on oxidatively modified LDL (Ox-LDL), lipoperoxide (LPO) cholesterol contents and SeGSHPx activities of plasma and tissues (aorta, heart and liver) in the established atherosclerotic rabbits. As compared with the control group, Ox-LDL, LPO and cholesterol contents were much lower; SeGSHPx activities and SeGSHPx/LPO ratios were much higher in plasma and tissues (aorta, heart and liver); and the lesion area of aortae was reduced in the PSK group. Through the increment of SeGSHPx activity in macrophages and aortae, PSK enhances their antioxidation potentiality and improves the antioxidant/prooxidant imbalance in them, and thus decreases Ox-LDL, LPO and cholesterol contents of plasma and tissues, and regresses lesion area of aortae in the established atherosclerotic rabbits.

Escape mechanisms in tumor immunity: a year 2000 update

The current consensus of opinion has it that most or possibly all tumors, spontaneous as well as induced, are immunogenic, expressing antigens in a form recognizable by the host immune system. Accordingly, in order to progress, tumors have to evolve strategies for evading immune responses. The purpose of this review is to consider the current status of knowledge concerning these different tumor escape strategies. It represents an update of an article originally published in this journal in 1997 (Pawelec, Zeuthen, and Kiessling, 1997). Therefore, it focuses mostly on publications that have appeared since then, illustrating the impressive accumulation of new data since that time and the importance currently attributed to studies of tumor escape from the immune response.

A multicentre study on eradication of Helicobacter pylori using four 1-week triple therapies in China

BACKGROUND

Short-term proton pump inhibitor-based triple therapies for the eradication of Helicobacter pylori are used widely. The eradication rates vary greatly from country to country and from region to region.

AIM

To assess the efficacy at eradicating H. pylori of 1-week regimens containing three medications: omeprazole (O) or colloidal bismuth subcitrate (B), furazolidone (F) or metronidazole (M), and amoxicillin (A) or clarithromycin (C).

METHODS

A multicentre study involving 20 hospitals in different regions of China. A total of 892 patients with H. pylori-positive non-ulcer dyspepsia or healed duodenal ulcer confirmed by endoscopy were recruited to receive, randomly, one of four regimens: OMC, OFC, OFA, and BFC, b.d. for 7 days. 13C-urea breath test was performed 4-8 weeks after completion of treatment.

RESULTS

The eradication rates with per protocol/intention-to-treat analyses were: OMC (n=217/219) 66%/65%; OFC (n=227/229) 69%/69%; OFA (n=223/225) 87%/86%; and BFC (n=214/219) 80%/78%. The eradication rate (per protocol analysis) in duodenal ulcer (79%) was higher than that in non-ulcer dyspepsia (73%, P=0.033). Patient compliance was good. The adverse events of the four regimens were mild, and mainly gastrointestinal.

CONCLUSIONS

The omeprazole, furazolidine and amoxicillin regimen achieves a high H. pylori eradication rate in different geographical regions of China.

Reduced IFN-gamma production in elderly people following in vitro stimulation with influenza vaccine and endotoxin

Cytokine interferon gamma (IFN-gamma) is pivotal in the defence against viruses and intracellular pathogens and an age-related decreased IFN-gamma production may explain the increased infectious disease morbidity and mortality in the elderly. Therefore, we performed a series of clinical experiments evaluating the influence of age and health status on IFN-gamma production following in vitro stimulation with influenza vaccine or endotoxin. Both healthy and frail elderly people produced significantly lower amounts of IFN-gamma following ex vivo stimulation with influenza vaccine or endotoxin. We conclude that ageing is accompanied by a decreased capacity to produce IFN-gamma. This may explain the increased incidence and case-fatality caused by viruses and intracellular pathogens in the elderly.

Experimental studies on long-wavelength instability and spiral breakup in a reaction-diffusion system

We investigate the behavior of spiral waves in a quasi-two-dimensional spatial open reactor using Belousov-Zhabotinsky reaction. The goal of this study is to answer two questions raised recently: Can a system sustain a stable long-wavelength modulated spiral? What causes the transition from spiral to defect-mediated turbulence? Our experimental results show that in a certain range of control parameters, a sustained long-wavelength modulated spiral is stable. The amplitude and the wavelength of modulations increase with the control parameter. As the latter is increased to across a threshold, defects are generated far away from the spiral center as a result of the neighboring two wave fronts being too close.

[Sulindac induced apoptosis of HT-29 colon adenocarcinoma cell]

This study was intended to examine whether sulindac induces apoptosis in the HT-29 cells. Flow cytometry, transmission electron microscopy and DNA electrophoresis were used. Flow cytometry, transmission electron microscopy and DNA electrophoresis all demonstrated that sulindac could induce apoptosis of the HT-29 cell line in a time- and dose-dependent manner. After treatment with 0.3 mmol/L, 0.6 mmol/L and 1.2 mmol/L sulindac for 48 hours, apoptotic cells in the treatment groups reached 5.8%, 7.6% and 11.7% versus 2.9% in the control group; after treatment for 72 hours, apoptotic cells in the treatment groups increased to 12.5%, 15.4% and 24.4% versus 5.1% in the control group, respectively, P < 0.05. This study has demonstrated that colon adenocarcinoma HT-29 cell line can be induced by sulindac.

[Isolation and phenotypic analysis of lamina propria mononuclear cells from colonoscopic biopsy specimens]

This study was directed to the method of isolation of lamina propria mononuclear cells (LPMC) from mucosal biopsy specimens and the phenotypic analysis of the cells. Ten biopsy specimens, taken individually from 8 patients with ulcerative colitis (UC), 5 normal controls and 22 patients with colorectal cancer, were collected to compare the factors that influence isolation and cell yield and to analyze the lymphocyte subsets by means of two-color flow cytometry. LPMC yield averaged 10(6) with a viability of more than 95% in UC, twice the yields in other two groups. The percentages of total T, B cells in three groups were similar (P > 0.05). When the UC group was compared with the other two groups, a significantly higher proportion of CD3(+)-CD4(+)-T cell (49.98% vs 37.54% and 37.25%, P < 0.01) was noted, whereas a lower proportion of CD3(+)-CD8(+)-T cell (23.64% vs 31.52% and 31.07%, P < 0.01) was observed. These data showed that the yield and viability of LPMC isolated from biopsy specimens were good enough for a phenotypic or functional analysis, which might be helpful to mucosal immune research on gut disorders, such as UC.

Transition from spirals to defect-mediated turbulence driven by a doppler instability

A transition from rotating chemical spirals to turbulence is observed in experiments on the Belousov-Zhabotinsky reaction. The transition occurs when the waves near the spiral tip spontaneously break, generating defects. Measurements reveal that this defect-mediated turbulence is caused by the Doppler effect on the traveling waves. The observations are in good accord with numerical simulations and theory.

The REG1 gene product is required for repression of INO1 and other inositol-sensitive upstream activating sequence-containing genes of yeast

A search was conducted for suppressors of the inositol auxotrophic phenotype of the ino4-8 mutant of yeast. The ino4-8 mutation is a single base pair change that results in substitution of lysine for glutamic acid at position 79 in the bHLH domain of the yeast regulatory protein, Ino4p. Ino4p dimerizes with a second bHLH protein, Ino2p, to form a complex that binds to the promoter of the INO1 gene, activating transcription. Of 31 recessive suppressors of ino4-8 isolated, 29 proved to be alleles of a single locus, identified as REG1, which encodes a regulatory subunit of a protein phosphatase involved in the glucose response pathway. The suppressor mutation, sia1-1, identified as an allele of REG1, caused constitutive INO1 expression and was capable of suppressing the inositol auxotrophy of a second ino4 missense mutant, ino4-26, as well as ino2-419, a missense mutation of INO2. The suppressors analyzed were unable to suppress ino2 and ino4 null mutations, but the reg1 deletion mutation could suppress ino4-8. A deletion mutation in the OPI1 negative regulator was incapable of suppressing ino4-8. The relative roles of the OPI1 and REG1 gene products in control of INO1 expression are discussed.

The effect of tert-butyl hydroperoxide on peritoneal macrophages and the protective effect of protein-bound polysaccharide administered intraperitoneally and orally

Our previous studies have shown that a protein-bound polysaccharide, polysaccharide krestin (PSK), can protect macrophages from lipoperoxidative injury induced by tert-butyl hydroperoxide (tbOOH) and oxidatively modified low density lipoprotein (O-LDL). PSK was administered intraperitoneally to mice, and the peritoneal macrophages harvested were used as an experimental model. PSK does not reveal any protective effect on macrophages injured by tbOOH when incubated in vitro. In order to elucidate its mode of action, in the present study, the protective effects of PSK were further investigated using morphological changes and viability as indices. It was shown that, compared with the non-PSK group, the viability of macrophages was much higher in the PSK group, and the morphological changes in the PSK group were much less than those in the non-PSK group. The protective effect of PSK administered intraperitoneally and orally on macrophages injured by tbOOH was comparable. Furthermore, the serum of the PSK treated mice had the same protective effect.

[Rapid microdose 14C-urea breath test for detection of Helicobacter pylori infection]

The purpose of this study was to develop and evaluate a rapid microdose 14C-urea breath test (14C-UBT) with a simplified protocol for detecting the infection of hilicobacter pylori (HP). 157 fasting patients who underwent endoscopy with histological examination and rapid urease test (RUT) were given a drink of 37 kBq of 14C-urea. Samples of breath carbon dioxide (1 mmol) were collected at baseline and 10, 20 and 30 min after administration by trapping in hyamine solution. 14C activity was measured by liquid scintillation counting. Results were expressed as cpm. Histolal examination and RUT were used as gold standard for the detection of HP infection. The cutoff value was selected as 200 cpm at 10 min. The results showed that the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.79%, 90.16%, 93.81%, 91.60% and 92.99% respectively. In this study, a 10 min, single sample, 37 kBq 14C-urea breath test for detection HP was developed. The test has good diagnostic accuracy with minimal radiation exposure and low cost. Thus, the authors considered the test to be reliable, safe, convenient and cost-effective to clinical use.

Modified ibogaine fragments: synthesis and preliminary pharmacological characterization of 3-ethyl-5-phenyl-1,2,3,4,5, 6-hexahydroazepino[4,5-b]benzothiophenes

Five phenyl-substituted derivatives and analogues of 1,2,3,4,5, 6-hexahydroazepino[4,5-b]indole, 5, a major fragment of ibogaine (1), were synthesized and tested for binding to monoamine transporters, the NMDA receptor-coupled cation channel, and dopamine and opioid receptors. All five derivatives, 9 and 17a-d, displayed 8-10-fold higher affinity at the DA transporter than ibogaine and noribogaine (4). At the serotonin transporter, two compounds (9 and 17a) exhibited higher potency than ibogaine, while the rest had weaker binding affinities than the lead compound. In keeping with their structural similarity to ibogaine, all five compounds displayed weak to poor affinity for dopamine D1 and D2 receptors. However, two compounds, 17a,c, demonstrated moderate binding affinities at dopamine D3 receptors. All five compounds displayed weak to poor affinities for mu and kappa opioid receptors and for the NMDA receptor-coupled cation channel. Despite the qualitative differences, derivatives and analogues of 5may serve as useful substitutes for ibogaine.

[Study on 102 cases of anorectal post-operational pain treated by long-acting analgesic]

OBJECTIVE

To observe the clinical effect and experimental result of long-acting analgesic in the treatment of anorectal post-operational pain.

METHODS

Analysing the pathological features of anorectal post-operational pain, and select the Radix Stephana Tetrandra, which could disperse pathogenic Wind and dampness, relieve spasm and pain, as the major component. The authors extracted Sinomenine from the Stephana and by mixing with methylene blue and bupivacaine hydrochloride, an injection was prepared. Three groups were in the clinical observation: Long-acting analgesic group (102 cases), routine treatment group (80 cases) and the control group treated by Tramal (30 cases). The curative effect was observed and animal experiment was conducted.

RESULTS

The total analgesic rate of the long-acting analgesia was 56.86%. The clinical effect was better than using Bupivacaini hydrochloride or Tramal alone (P < 0.05). It was shown in experiment that long-acting analgesic had obvious effects of topical analgesic and muscle relaxant.

CONCLUSIONS

Long-acting analgesic has significant effect in relieving the anorectal post-operational pain.

DNA solution of the maximal clique problem

The maximal clique problem has been solved by means of molecular biology techniques. A pool of DNA molecules corresponding to the total ensemble of six-vertex cliques was built, followed by a series of selection processes. The algorithm is highly parallel and has satisfactory fidelity. This work represents further evidence for the ability of DNA computing to solve NP-complete search problems.

Parallel overlap assembly for the construction of computational DNA libraries

Algorithms for computing with DNA currently require the construction of pools of molecules in which each distinct molecule represents a different starting point for the calculation. We have begun building such pools using the technique of parallel overlap assembly that is already used for the generation of diversity in biologically useful combinatorial search techniques such as gene shuffling. Unlike these applications, a pool in a molecular computer must be complete, containing all possible strands, and ordered, having minimal contamination from incorrectly assembled DNA. We present an experiment in which parallel overlap assembly is used to construct a computational pool and an experiment in which this pool is used to solve the NP-complete maximal-clique problem.

[Investigation of relationship between primary gastric malignant lymphoma and Helicobacter pylori infection]

In order to investigate the relationship between primary gastric malignant lymphoma (PGML) and helicobacter pylori (Hp) infection, the gastric mucosa of 39 cases of PGML and 22 cases of lymphocytic gastritis, 32 cases of Hp unrelated diseases was collected in this case-control study. Hp infection was confirmed by modified Giemsa stain; PGML was classified by Isaacson's classification.

RESULT

The Hp detecting rate of PGML was 87.18%, which was significantly higher than that of control groups that was 63.64%, 53.13% respectively (P < 0.005). Mucosa-associated lymphoid tissue (MALT) type was accounted for 92.31% of PGML cases with Hp detecting rate 86.11%. In surrounding chronic active gastritis and lymphoid-follicles Hp were detected in 84.62%, 56.41% cases respectively.

IN CONCLUSION

histology shows a good relationship between B cell gastric MALT lymphoma and Hp infection.