[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.

[Laboratory diagnosis of tuberculous peritonitis]

OBJECTIVE

To evaluate the diagnostic value of polymerase chain reaction (PCR) assay in combination with Southern hybridization technique and enzyme-linked immunosorbent assay (ELISA) in tuberculous peritonitis.

METHODS

Fourty-two tuberculous ascites were detected for M. tuberculosis by PCR technique in combination with Southern hybridization, in which nuclear acid probe was digoxigenin-labeled, and the result was compared with conventional bacteriological methods and ELISA. IS6110, a specific insert sequence of M. tuberculosis, was used as primer. The specificity of PCR products was confirmed by hybridization and digestion with Sal I restrictive endonuclerase, and the sensitivity of hybridization was compared with gel electrophoresis.

RESULTS

The sensitivities were 69% by PCR, 71% by ELISA, 9% by culture and 0 by acid fast staining respectively. Hybridization was found more sensitive than gel electrophoresis.

CONCLUSIONS

Both PCR technique and ELISA are valuable in diagnosis of tuberculous peritonitis, and the former is more specific than the latter. PCR technique in combination with Southern hybridization can improve both the sensitivity and the specificity of dectection.

[Mycobacterium paratuberculosis in the intestine of patients with Crohn's disease]

Crohn's disease has long been suspected of having a mycobacteria, specifically M. paratuberculosis cause. In this study polymerase chain reaction (PCR) assay was used to detect M. paratuberculosis DNA in 74 paraffin wax embedded gut tissues from endoscopic biopsy or surgical resection specimens, including 36 Crohn's disease tissues, 18 ulcerative colitis tissues and 20 non-inflammatory bowel disease tissues. Oligonucleotides derived from IS900 sequence, which is a repeated in M. paratuberculosis chromosome and highly specific for the M. paratuberculosis, were used as primer. The specificity of products was confirmed by southern blot hybridization by using a biotin-labeled probe. The results show that M. paratuberculosis DNA was detected in 17 Crohn's disease (47.2%), 2 ulcerative colitis (11.1%) and 3 non-inflammatory bowel disease control subjects (15.0%). PCR positive or negative results in 36 Crohn's disease show that there is no relation with small or large gut involvement, and also the presence or absence of granulomata. The results suggest that M. paratuberculosis is surely present in tissues from some patients with Crohn's disease, which may have a specific association with Crohn's disease.

[Cloning and sequencing of nucleoprotein gene of Chinese rabies virus vaccine strain (5aG)]

Rabies virus 5aG strain (5aGRV) is used to produce primary hamster kidney tissue culture vaccine against Rabies in China. Nucleoprotein (NP), an important constituent of rabies virus, can intrigue Th cell and induce B cell to produce antibody. In order to study the molecular and biological characteristics of 5aG NP, we have cloned and sequenced the nucleoprotein gene. First, total RNA was extracted from infected mouse brain by Guanidine Isothiocyanate one-step method, then the first strand cDNA was synthesized by reverse transcription with oligo (dT) 18 as primer. After RACE (Rapid Amplification of cDNA Ends), one pair of oligonucleotide primers designed referring to the nucleoprotein gene of other strains, were used in PCR to amplify the fragments of nucleoprotein gene (1.4kb). When these fragments were inserted into vector pUC18, sequences of the nucleoprotein gene were obtained by double-stranded sequencing. Comparing the nucleic acid and deduced amino acid sequence of 5aGRV nucleoprotein gene with available NP sequences of other RV strains, we found that the nucleoprotein has less variation than glycoprotein, so nucleoprotein is more suitable to be used as a diagnostic reagent and a subunit vaccine.

Teaching and assessing clinical skills: a competency-based programme in China

The objective of this study was to develop a competency-based clinical skills teaching and assessment programme in China utilizing modern teaching techniques. Medical teachers from three schools agreed on items for inclusion in the complete physical examination of an asymptomatic adult, an outline for an adult and paediatric history, and important interviewing skills. Lesson plans, performance checklists, and written and videotape training materials were developed. Standardized patients were trained at one school to assist with the teaching at that school and with the assessment at all three schools. A national, a provincial, and a local medical school in China were used. Before beginning the new curriculum for students in their first year of clinical training, baseline data were collected on skills of students at various levels of training in the previous curriculum at all three schools. Although in the previous curriculum there was some improvement in clinical skills among advanced compared to more junior students, performance was lower than expected by staff. One year after implementation of the new curriculum, students were evaluated. These students significantly outperformed their counterparts as well as the more senior level students tested the previous year. This project has established a competency-based teaching and assessment programme in China that allows for rapid improvement in the clinical skills of students. Within a short time, a sophisticated group of medical educators has been formed, who now function as consultants to other educators in their own country. Many aspects of this programme are being adapted throughout China and are applicable to medical schools throughout the world.

Pharmacological screen for activities of 12-hydroxyibogamine: a primary metabolite of the indole alkaloid ibogaine

The purported efficacy of ibogaine for the treatment of drug dependence may be due in part to an active metabolite. Ibogaine undergoes first pass metabolism and is O-demethylated to 12-hydroxyibogamine (12-OH ibogamine). Radioligand binding assays were conducted to identify the potency and selectivity profiles for ibogaine and 12-OH ibogamine. A comparison of 12-OH ibogamine to the primary molecular targets identified previously for ibogaine demonstrates that the metabolite has a binding profile that is similar, but not identical to the parent drug. Both ibogaine and 12-OH ibogamine demonstrated the highest potency values at the cocaine recognition site on the 5-HT transporter. The same rank order (12-OH ibogamine > ibogaine), but lower potencies were observed for the [3H]paroxetine binding sites on the 5-HT transporter. Ibogaine and 12-OH ibogamine were equipotent at vesicular monoamine and dopamine transporters. The metabolite demonstrated higher affinity at the kappa-1 receptor and lower affinity at the NMDA receptor complex compared to the parent drug. Quantitation of the regional brain levels of ibogaine and 12-OH ibogamine demonstrated micromolar concentrations of both the parent drug and metabolite in rat brain. Drug dependence results from distinct, but inter-related neurochemical adaptations, which underlie tolerance, sensitization and withdrawal. Ibogaine's ability to alter drug-seeking behavior may be due to combined actions of the parent drug and metabolite at key pharmacological targets that modulate the activity of drug reward circuits.

[Expression of p53 protein in colorectal cancer and its relationship to cell proliferative activity and prognosis]

The expression of p53 protein in 66 cases of colorectal cancer and its relationship to cell proliferative activity, lymph node metastasis as well as prognosis were investigated by means of AB-PAP immunohistochemical technique. The results showed that 62.1% of colorectal cancer was positive. The cell proliferative activity and the frequency of lymph node metastasis in p53-positive cases were significantly higher than those of p53-negative cases (P < 0.05). The survival rate in patients with p53-positive tumors was significantly shorter than those with p53-negative tumors (P < 0.05). Our results suggest that the abnormal expression of p53 and cell proliferation associated with mutations are involved in both human carcinogenesis and lymph node metastasis of colorectal cancer. Examination of p53 expression is of value in understanding the degree of malignancy, and evaluating prognosis of the disease.

Functional characterization of an inositol-sensitive upstream activation sequence in yeast. A cis-regulatory element responsible for inositol-choline mediated regulation of phospholipid biosynthesis

A repeated element, the inositol-sensitive upstream activation sequence (UASINO), having the consensus sequence, 5'-CATGTGAAAT-3', is present in the promoters of genes encoding enzymes of phospholipid biosynthesis that are regulated in response to the phospholipid precursors, inositol and choline. None of the naturally occurring variants of the UASINO element exactly recapitulates the consensus (for review, see Carman, G. M., and Henry, S. A. (1989) Annu. Rev. Biochem. 58, 635-669 and Paltauf, F., Kolwhein, S., and Henry, S. A. (1992) in Molecular Biology of the Yeast Saccharomyces cerevisiae (Broach, J., Jones, E., and Pringle, J., eds) Vol. 2, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY). The first six bases of the UASINO element are homologous with canonical binding motif for proteins of the basic helix-loop-helix (bHLH) family. Two bHLH regulatory proteins, Ino2p and Ino4p from yeast, were previously shown to bind to promoter fragments containing this element. In the present study, an extensive analysis of UASINO function has been conducted. We report that any base substitution within the putative bHLH binding site resulted either in a dramatic reduction or in a complete obliteration of UASINO function as tested in an expression assay in vivo. Base substitutions in the 5' region that flanks the 10-base pair repeat, as well as sequences within the repeat itself at its 3' end outside the bHLH core, were also assessed. The two bases immediately flanking the 5' end of the element proved to be very important to its function as a UAS element as did the two bases immediately 3' of the bHLH core motif. Substitutions of the final two bases of the original ten base pair consensus (i.e. 5'-CATGTGAAAT-3') had less dramatic effects. We also tested a subset of the altered elements for their ability to serve as competitors in an assay of Ino2p x Ino4p binding. The strength of any given sequence as a UASINO element, as assayed in vivo, was strongly correlated with its strength as a competitor for Ino2p x Ino4p binding. We also tested a subset of the modified UASINO elements for their effects on expression in vivo in a strain carrying an opi1 mutation. The opi1 mutation renders the coregulated enzymes of phospholipid synthesis constitutive in the presence of phospholipid precursors. All elements that retained some residual UASINO activity when tested in the wild-type strain were constitutively expressed at a level comparable with the wild-type derepressed level when tested in the opi1 mutant.(ABSTRACT TRUNCATED AT 400 WORDS)

Value of polymerase chain reaction assay in diagnosis of intestinal tuberculosis and differentiation from Crohn's disease

It is difficult to make a precise diagnosis of intestinal tuberculosis and to differentiate it from Crohn's disease. For evaluating Polymerase Chain Reaction (PCR) assay in these two aspects, 36 specimens of intestinal tuberculosis from surgical resections and endoscopic biopsies and 26 Crohn's disease samples were subjected to PCR assay. 21 specimens of normal colon tissue surrounding cancer were used as the control. Oligonucleotides derived from the IS 6110 sequence, which is repeated in M. tuberculosis chromosome and highly specific for the M. tuberculosis complex, were used as a primer. The amplified PCR products were detected by examination of ethidium-bromide-stained polyacrylamide gels. The specificity of PCR products was confirmed by digestion with Sal I restrictive endonuclease and southern blot hybridization using digoxigenin-labeled probe. The results showed that the M. tuberculosis DNA was identified in 27/36 intestinal tuberculosis, but none of 26 Crohn's disease. Acid fast bacilli were only found in 16/36 intestinal tuberculosis. In conclusion, as a rapid, sensitive, and specific pathogenic method in diagnosis of intestinal tuberculosis, PCR assay has been developed in this study, and is considered valuable in the differentiation between intestinal tuberculosis and Crohn's disease.

[The value of polymerase chain reaction assay in the diagnosis of intestinal tuberculosis and differentiation from Crohn's disease]

It is difficult to make a precise diagnosis for intestinal tuberculosis and differentiate it from Crohn's disease. For evaluating the efficacy of PCR assay in these two aspects, 36 specimens of intestinal tuberculosis and 26 of Crohn's disease from surgical resections and endoscopic biopsies were subjected to PCR assay. Oligonucleotides derived from IS 6110 sequence, which is a repeated in M. tuberculosis chromosome and highly specific for the M. tuberculosis complex, were used as a primer. The specificity of PCR products was confirmed by digestion with Sal I restrictive endonuclease and southern blot hybridization by using digoxigenin-labeled probe. The results showed that M. tuberculosis DNA was identified in 27 of the 36 specimens of intestinal tuberculosis, but none in those of 26 Crohn's disease. In conclusion, PCR is a rapid, sensitive and specific method for the diagnosis of intestinal tuberculosis, and it is also valuable in differentiating intestinal tuberculosis from Crohn's disease.