Cloning and identification of a novel sperm binding protein, HEL-75, with antibacterial activity and expressed in the human epididymis

BACKGROUND

The HEL-75 protein is a beta-defensin that was identified by analyzing a human epididymis cDNA library. Studying its function may not only elucidate the mechanisms of host defense, but may also provide new alternatives for novel therapeutic drugs for reproductive tract infections.

METHODS

The HEL-75 gene was amplified by PCR, and its structure and function were predicted and analyzed with bioinformatics tools. Polyclonal serum was raised against recombinant HEL (rHEL)-75 protein. The gene expression pattern was analyzed with RT-PCR and immunofluorescent staining. Finally, the antimicrobial activity and function during fertilization of HEL-75 were analyzed using a colony-forming unit assay and IVF, respectively.

RESULTS

The human HEL-75 gene is located on chromosome 20p13 and encodes a 95 amino acid protein with a predicted N-terminal signal peptide of 22 amino acids. The protein has six conserved cysteine residues, characteristic of members of the beta-defensin superfamily, as well as several potential post-translational modification sites. At the transcriptional level, HEL-75 was expressed in the epididymis and lung, but only in the epididymis at the translational level. Immunofluorescent staining showed that HEL-75 protein bound spermatozoa in the epididymis. RHEL-75 protein could kill Escherichia coli in vitro in a dose- and time-dependent fashion. However, no effect was observed on sperm motility nor fertilization when spermatozoa were blocked with anti-rHEL-75 polyclonal serum.

CONCLUSION

HEL-75 is a new beta-defensin expressed in the epididymis and on sperm; it may play an important role in host defense.

Analyses of the floral organ morphogenesis and the differentially expressed genes of an apetalous flower mutant in Brassica napus

The floral organ morphogenesis of the apetalous flower mutant Apet33-10 in Brassica napus was investigated and the result showed that all the floral organ morphogenesis was normal except that petal primordium was not observed during flower development. Eighteen genes were found to be down regulated in early floral buds (less than 200 mum in length) of Apet33-10 at the stage of floral organ initiation by means of suppressive subtraction hybridization (SSH) and RT-PCR. These genes were involved in petal identity, calcium iron signal transduction, mRNA processing, protein synthesis and degradation, construction of cytoskeleton, hydrogen transportation, nucleic acid binding, alkaloid biosynthesis and unknown function. Three overall coding region cDNAs of APETALA3 (AP3) gene, BnAP3-2, BnAP3-3 and BnAP3-4 were obtained by RT-PCR, respectively. Real-time quantitative PCR analysis showed that the expression ratio among BnAP3-2, BnAP3-3 and BnAP3-4 was 3.67:3.68:1 in early floral buds of wild type Pet33-10. The expression level of BnAP3-2, BnAP3-3 and BnAP3-4 in early floral buds of Apet33-10 was down-regulated to 36.6, 28.3 and 66.8% with the comparison of that of wild type, respectively, and the overall expression level of AP3 genes in apetalous mutant amounted to 45.0% of that in wild type. The difference in the expression level of each AP3 gene in stamen between apetalous and wild type lines was not significant. It is suggested that lower abundant expression of AP3 genes during the early flower development might be enough for stamen primordium initiation, but not enough for petal primordium initiation in the apetalous line Apet33-10.

WITHDRAWN: Neoadjuvant chemotherapy versus none for resectable gastric cancer

BACKGROUND

Gastric cancer is a major cause of cancer death, and many patients are only diagnosed when the cancer has reached an advanced stage. Neoadjuvant chemotherapy (NAC), that is, chemotherapy administered shortly before surgical treatment, could provide a method of increasing the possibility of complete resection and survival.

OBJECTIVES

To evaluate the effect of neoadjuvant chemotherapy versus none for patients with resectable gastric cancer in terms of efficacy and toxicity.

SEARCH STRATEGY

Electronic databases including Cochrane Library, MEDLINE, EMBASE, CancerLit, Chinese Biomedical Literature Database (CBMDISC) and ongoing clinical trials as well as handsearching of conference proceedings, were searched to retrieve relevant data.

SELECTION CRITERIA

Randomized controlled clinical trials of neoadjuvant chemotherapy on resectable gastric cancer.

DATA COLLECTION AND ANALYSIS

We identified a total of 36 published citations or meeting abstracts. Thirty-two items were excluded. Of the four remaining studies, three stated random allocation but the method of randomization was unclear. Two of these employed allocation concealment by sealed envelope which was controlled by an independent party. None of the trials was double blind. All trials presented a detailed description of the number of withdrawals, dropouts and losses to follow-up.

MAIN RESULTS

Of the four clinical trials enrolled, there were 250 and 332 cases in total, with 106 and 126 deaths at the end of follow-up in the NAC and control group, respectively. The OR (odds ratio) was 1.05 (95%CI: 0.73-1.50), which was not statistically significant. Of the evaluable 129 patients receiving NAC, 28.7% demonstrated either a complete or a partial response. Two studies of NAC in resectable gastric cancer had resection rate data available for analysis The R0 resection rate in the NAC group was comparable to that in the control (OR: 0.96 (95%CI: 0.51-1.83)). The morbidity and mortality of NAC varied with the regimens used preoperatively. Of the 129 patients included in the analyzed studies, some acceptable toxicity was observed.

AUTHORS' CONCLUSIONS

There is no definite evidence of the effectiveness of NAC in resectable gastric cancer, in terms of improvements in patient survival, in the trials we reviewed. Neoadjuvant chemotherapy should not be used routinely in clinical setting until further results from randomized clinical are available. Neoadjuvant chemotherapy of gastric cancer should be applied under the framework of clinical trials.

A novel DFNA5 mutation, IVS8+4 A>G, in the splice donor site of intron 8 causes late-onset non-syndromic hearing loss in a Chinese family

We report here the clinical, genetic, and molecular characteristics of a large Chinese family exhibiting non-syndromic, late-onset autosomal dominant sensorineural hearing loss. Clinical evaluation revealed variable phenotypes of hearing loss in terms of severity and age-at-onset of disease in these subjects. Genome-wide linkage analysis mapped the disease gene to the DFNA5 locus with a maximum two-point log odds score of 5.39 at [theta] = 0 for marker D7S2457. DNA sequencing of DFNA5 revealed a novel heterozygous IVS8+4 A>G substitution in the splice donor site of intron 8. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed skipping of exon 8 in the mutant transcript. This mutation faithfully cosegregated with hearing loss in the family. In addition, the mutation was absent in 100 unrelated control DNA samples of Chinese origin. The IVS8+4 A>G mutation is predicted to create a shift in the reading frame and introduce a stop codon at position 372, thereby resulting in a prematurely truncated DFNA5 protein. Up to date, a total of four mutations in DFNA5 have been reported to lead to hearing impairment, all of them result in skipping of exon 8 at the mRNA level. Our findings provide further support for the hypothesis that DFNA5-associated hearing loss is caused by a very specific gain-of-function mutation.

Tissue culture-induced locus-specific alteration in DNA methylation and its correlation with genetic variation in Codonopsis lanceolata Benth. et Hook. f

We have reported recently that tissue culture induced a high level of genetic variation at the primary nucleotide sequence in regenerants of medicinal plant Codonopsis lanceolata. It is not known, however, whether epigenetic variation in the form of alteration in DNA methylation also occurred in these plants. Here, we investigated possible alterations in level and pattern of cytosine methylation at the CCGG sites in the same set of regenerants relative to the donor plant, by the MSAP method employing a pair of isoschizomers, HpaII and MspI, which recognize the same restriction site but are differentially sensitive to cytosine methylation at the CCGG sites. A total of 1,674 MSAP profiles were resolved using 39 primer combinations. Of these, 177 (10.5%) profiles were polymorphic among the regenerants and/or between the regenerant(s) and the donor plant, in EcoRI + HpaII or EcoRI + MspI digest but not in both, indicating alteration in cytosine methylation patterns of specific loci, though their estimated total level of methylation remained more or less the same as the donor plant. Gel blot analysis validated most of the variant MSAP profiles as bona fide alteration in methylation patterns. Correlation analysis between the MSAP data and the previously reported ISSR and RAPD data revealed significant correlations, suggesting their possible intrinsic interrelatedness. Thirty-seven typical variant MSAP profiles were isolated and sequenced, of which 5 showed significant homology to known-function genes, 2 to chloroplast sequences, whilst the rest 30 did not find a match in the database.

Neoadjuvant chemotherapy versus none for resectable gastric cancer

BACKGROUND

Gastric cancer is a major cause of cancer death, and many patients are only diagnosed when the cancer has reached an advanced stage. Neoadjuvant chemotherapy (NAC), that is, chemotherapy administered shortly before surgical treatment, could provide a method of increasing the possibility of complete resection and survival.

OBJECTIVES

To evaluate the effect of neoadjuvant chemotherapy versus none for patients with resectable gastric cancer in terms of efficacy and toxicity.

SEARCH STRATEGY

Electronic databases including Cochrane Library, MEDLINE, EMBASE, CancerLit, Chinese Biomedical Literature Database (CBMDISC) and ongoing clinical trials as well as handsearching of conference proceedings, were searched to retrieve relevant data.

SELECTION CRITERIA

Randomized controlled clinical trials of neoadjuvant chemotherapy on resectable gastric cancer.

DATA COLLECTION AND ANALYSIS

We identified a total of 36 published citations or meeting abstracts. Thirty-two items were excluded. Of the four remaining studies, three stated random allocation but the method of randomization was unclear. Two of these employed allocation concealment by sealed envelope which was controlled by an independent party. None of the trials was double blind. All trials presented a detailed description of the number of withdrawals, dropouts and losses to follow-up.

MAIN RESULTS

Of the four clinical trials enrolled, there were 250 and 332 cases in total, with 106 and 126 deaths at the end of follow-up in the NAC and control group, respectively. The OR (odds ratio) was 1.05 (95%CI: 0.73-1.50), which was not statistically significant. Of the evaluable 129 patients receiving NAC, 28.7% demonstrated either a complete or a partial response. Two studies of NAC in resectable gastric cancer had resection rate data available for analysis The R0 resection rate in the NAC group was comparable to that in the control (OR: 0.96 (95%CI: 0.51-1.83)). The morbidity and mortality of NAC varied with the regimens used preoperatively. Of the 129 patients included in the analyzed studies, some acceptable toxicity was observed.

AUTHORS' CONCLUSIONS

There is no definite evidence of the effectiveness of NAC in resectable gastric cancer, in terms of improvements in patient survival, in the trials we reviewed. Neoadjuvant chemotherapy should not be used routinely in clinical setting until further results from randomized clinical are available. Neoadjuvant chemotherapy of gastric cancer should be applied under the framework of clinical trials.

Screening and mutagenesis of a novel Bacillus pumilus strain producing alkaline protease for dehairing

AIMS

To characterize and optimize a novel Bacillus pumilus strain isolated from biological waste which produces protease with excellent dehairing effect. This newly isolated strain could be utilized in the industrial leather dehairing process.

METHODS AND RESULTS

Bacterial strains secreting proteases were screened from biological wastes. Positive clones were further characterized by analysing their efficacy in dehairing and effects on collagen integrity. Among 171 colonies tested, a strain BA06, identified as B. pumilus, was picked owing to its efficient dehairing capabilities with minimal impact on collagen. By combined mutagenesis using UV, N-methyl-N'-nitro-N-nitrosdguanidine and Co(60)-gamma-rays, this strain was further improved with regard to its alkaline protease production. The alkaline protease activity of the mutant strain SCU11was greatly improved up to 6000 U ml(-1), in comparison with its parent strain BA06 of 1200 U ml(-1).

CONCLUSIONS

By using screening and mutagenesis methods, we have successfully created a B. pumilus strain that can produce high levels of alkaline proteases that are able to efficiently remove hair from skin with minimal damage on the collagen.

SIGNIFICANCE AND IMPACT OF THE STUDY

This strain could be used in commercial alkaline protease production for leather dehairing.

Estimation of beat-to-beat systolic blood pressure using pulse arrive time and pulse width derived from the photoplethysmogram

Continuous arterial blood pressure monitoring is essential in monitoring patients during surgical operation or in intensive care units. In this study, we propose a new method to estimate beat-to-beat systolic blood pressure by combining the pulse arrive time and normalized pulse width measurement. The method was examined in nine patients who were in ICU. Results shows the new method has higher linearity (0.8218) and better precision (3.0775) than the methods using either pulse arrive time or pulse width only.

Addressing Taiwan's high incidence of cervical cancer: factors associated with the Nation's low compliance with Papanicolaou screening in Taiwan

BACKGROUND

Despite cervical cancer being the leading female cancer, women in Taiwan have received fewer screening examinations for this disease than populations in Western countries.

METHODS

Randomly selected telephone questionnaire interviews with women aged 20 years and over were conducted to investigate the factors associated with the subject's cancer screening practices.

RESULTS

Among 1021 respondents, 51.6% self-reported no Papanicolaou (Pap) examination received within their lifetime. The multivariate logistic regression analysis revealed that, in addition to marital status, cancer knowledge was the most significant factor associated with screening practice compliance. Compared with women with correct answers for 22-28 cancer knowledge questions, the odds ratios (OR) for non-compliance were 1.4 (95% confidence interval (CI)=1.0-2.0) for women with 17-21 correct answers and 2.3 (95% CI=1.6-3.4) for women with less than 17 correct answers. Women aged 40-49 years had the best cancer knowledge scores. Unmarried women were at an elevated risk for no Pap examination (OR=7.6, 95% CI=5.2-11.3).

CONCLUSIONS

Women in Taiwan should be targeted for intervention to promote cancer knowledge and screening compliance.

Bioprocess monitoring and computer control: key roots of the current PAT initiative

This review article has been written for the journal, Biotechnology and Bioengineering, to commemorate the 70th birthday of Daniel I.C. Wang, who served as doctoral thesis advisor to each of the co-authors, but a decade apart. Key roots of the current PAT initiative in bioprocess monitoring and control are described, focusing on the impact of Danny Wang's research as a professor at MIT. The history of computer control and monitoring in biochemical processing has been used to identify the areas that have already benefited and those that are most likely to benefit in the future from PAT applications. Past applications have included the use of indirect estimation methods for cell density, expansion of on-line/at-line and on-line/in situ measurement techniques, and development of models and expert systems for control and optimization. Future applications are likely to encompass additional novel measurement technologies, measurements for multi-scale and disposable bioreactors, real time batch release, and more efficient data utilization to achieve process validation and continuous improvement goals. Dan Wang's substantial contributions in this arena have been one key factor in steering the PAT initiative towards realistic and attainable industrial applications.

Micrometastases detected by cytokeratin 19 expression in sentinel lymph nodes of patients with early-stage cervical cancer

The purpose of this study was to detect micrometastases in sentinel lymph nodes (SLNs) by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) analyses for cytokeratin 19 (CK19) expression in early-stage cervical cancer. One hundred twenty-five SLNs were collected from 46 patients with early-stage cervical cancer. Conventional histopathologic techniques revealed 14 metastatic SLNs from 11 out of 46 patients. CK19 expression was detected by RT-PCR and IHC in all the 125 SLNs. Cervical cancer tissues from nine patients and five pelvic lymph nodes from the patients without tumor were utilized as positive and negative controls, respectively. All the metastastic SLNs on conventional histopathologic techniques were positive by either RT-PCR or IHC analyses, while all the positive controls were positive and all the negative controls were negative as expected. Of 35 patients without metastatic SLNs on conventional histopathologic techniques, the detection rate of micrometastases was 42.85% by RT-PCR and 20% by IHC analyses. RT-PCR and IHC were more sensitive to identify micrometastases in SLNs of patients with early-stage cervical cancer than routine pathology. These findings demonstrated that micrometastasis could be identified by molecular technique such as RT-PCR and IHC analyses for CK19 expression. RT-PCR was more sensitive to detect micrometastases in SLNs than IHC in patients with early-stage cervical cancer. Therefore, molecular assessment of the SLNs may be a valuable tool to complement routine histologic examination of cervical cancer. The importance of micrometastases in SLNs is under close clinical observation to determine whether it can be used as a predicting factor to help us make decision whether to proceed with whole-pelvic lymph node dissection or as a prognostic factor for clinical outcome.

STAT3 induces transcription of the DNA methyltransferase 1 gene (DNMT1) in malignant T lymphocytes

In this study, we demonstrated that STAT3, a well-characterized transcription factor expressed in continuously activated oncogenic form in the large spectrum of cancer types, induces in malignant T lymphocytes the expression of DNMT1, the key effector of epigenetic gene silencing. STAT3 binds in vitro to 2 STAT3 SIE/GAS-binding sites identified in promoter 1 and enhancer 1 of the DNMT1 gene. STAT3 also binds to the promoter 1 region and induces its activity in vivo. Treatment of the malignant T lymphocytes with STAT3 siRNA abrogates expression of DNMT1, inhibits cell growth, and induces programmed cell death. In turn, inhibition of DNMT1 by a small molecule inhibitor, 5-aza-2-deoxy-cytidine, and 2 DNMT1 antisense DNA oligonucleotides inhibits the phosphorylation of STAT3. These data indicate that STAT3 may in part transform cells by fostering epigenetic silencing of tumor-suppressor genes. They also indicate that by inducing DNMT1, STAT3 facilitates its own persistent activation in malignant T cells. Finally, these data provide further rationale for therapeutically targeting STAT3 in T-cell lymphomas and, possibly, other malignancies.

Wheezing in Chinese schoolchildren: disease severity distribution and management practices, a community-based study in Hong Kong and Guangzhou

BACKGROUND

Asthma is a common chronic disease and information on its management practices at the community level is helpful in identifying problems and improving asthma care.

OBJECTIVE

To assess the severity status and management of the asthma symptom of wheeze of children at the community level in Hong Kong (HK) and Guangzhou (GZ).

METHODS

Cross-sectional study of children aged 10 years using the International Study of Asthma and Allergic disease in Childhood (ISAAC Phase II protocol). Asthma management and lung function were assessed in 178 (98 from HK and 80 from GZ) randomly selected children with wheeze over the past 12 months.

RESULTS

Eighty-three percent, 11%, 6% and 0% of children suffered from intermittent, mild persistent, moderate persistent and severe persistent asthma, respectively, according to the frequency of their symptoms. Addition of spirometric parameter only changed the asthma severity classification in 2.8% of children. Medications were used by 30.6% and 71.3% of children for wheeze in HK and GZ, respectively. In HK, inhaled beta(2)-agonist (73.3% among the drug users) was the commonest medication used followed by inhaled corticosteroid (ICS) (23.3%). In GZ, inhaled beta(2)-agonist was used by 75.4% of children, but use of ICS (26.3%), oral beta(2)-agonist (26.3%), oral theophylline (45.6%), oral ketotifen (36.8%) and oral steroid (35.1%) were also common. ICS was only used by 11.4% of children with persistent asthma. Ten percent and 18.7% of children in HK and GZ, respectively, had emergency department visits, while 16.3% and 11.6% of children in HK and GZ, respectively, had missed school secondary to asthma over the past 1 year.

CONCLUSIONS

Most children in the community had intermittent asthma and addition of lung function to symptoms did not significantly affect classification of asthma severity. Significant morbidity was seen even in this group of children with mostly intermittent and mild persistent asthma.

Association between Polymorphisms of Vitamin D Receptor Gene ApaI, BsmI and TaqI and Muscular Strength in Young Chinese Women

The association between the polymorphisms of vitamin D receptor gene ApaI, BsmI and TaqI and isokinetic muscular strength was examined in 109 healthy, young Chinese women.

METHODS

Genomic DNA was extracted from mouthwash samples and vitamin D receptor genotypes were determined with the established methods. The peak torque of the dominant limb in concentric and eccentric knee extensors and flexors and elbow extensors and flexors was measured using Cybex-Norm-770 isokinetic dynamometer at slow and fast velocities. The distribution frequency of vitamin D receptor gene alleles was analyzed by chi-square test. The difference in muscular strength between VDR genotype groups was analyzed using one-way ANOVA. The ApaI, BsmI and TaqI alleles and genotype frequencies appeared to be in a Hardy-Weinberg equilibrium. Subjects with the vitamin D receptor ApaI null (A allele) mutation (AA) exhibited significantly lower knee and elbow concentric or eccentric peak torque than those with aa homozygous or Aa heterozygous. The BB & Bb group showed significantly higher peak torque in concentric knee flexors than bb group. No association was found between vitamin D receptor gene TaqI and muscular strength. The data indicated that vitamin D receptor gene ApaI and BsmI polymorphisms rather than TaqI polymorphism might be associated with muscular strength.

STAT3- and DNA methyltransferase 1-mediated epigenetic silencing of SHP-1 tyrosine phosphatase tumor suppressor gene in malignant T lymphocytes

Expression of SHP-1 phosphatase, a key negative regulator of cell signaling, is lost in T cell lymphomas and other malignancies due to DNA methylation of the SHP-1 promoter by a currently undefined mechanism. We demonstrate that malignant T cells express DNA methyltransferase (DNMT) 1 and that constantly activated signal transducer and activator of transcription (STAT) 3 is capable of binding in vitro to DNA oligonucleotides corresponding to four STAT3 SIE/GAS binding sites identified in the SHP-1 promoter. STAT3, DNMT1, and histone deacetylase 1 form complexes and bind to the SHP-1 promoter in vivo. Treatment with pharmacologic grade DNMT1 anti-sense oligonucleotides and STAT3 small-interfering RNA induces in the malignant T cells DNA demethylation and expression of SHP-1 gene. These data indicate that STAT3 may, in part, transform cells by inducing epigenetic silencing of SHP-1 in cooperation with DNMT1 and, apparently, histone deacetylase 1. Reversal of such gene silencing represents an attractive aim for novel anticancer therapies.

The genetic epidemiology of alopecia areata in China

BACKGROUND

Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease with genetic predisposition and an environmental trigger. There are few clinical data in Asians.

OBJECTIVES

To describe the genetic epidemiological features of AA patients in China and to determine the possible genetic model for AA.

METHODS

Data for 1032 patients with AA were obtained by questionnaire in the Institute of Dermatology of Anhui Medical University in China from 2001 to 2003. Complex segregation analysis and heritability analysis were performed using Falconer's method, EPI INFO 6.0 and SAGE-REGTL programs.

RESULTS

In total, 1032 AA patients (male/female ratio 1.1 : 1) were enrolled, representing 0.94% of the total number of cases seen in our outpatient clinic during that time. The mean +/- SD age of onset was 28.98 +/- 13.43 years. The difference between the mean age of onset in males and females was not significant. Most patients (82.6%) experienced their first episode of AA within the first four decades of life. A positive family history of AA was obtained in 87 patients (8.4%). The prevalence of AA in first-, second- and third-degree relatives of the proband with AA was 1.6%, 0.19% and 0.03%, respectively. These figures were higher than those in controls. A greater severity and longer duration of AA were seen in the early onset group than in the late-onset group. The early onset group also had more affected first- and second-degree relatives. The heritability of AA in first-, second- and third-degree relatives was 47.16%, 42.53% and 22.29%, respectively. Based on the REGTL results, the best model was a polygenic additive model for AA.

CONCLUSIONS

The effect of genetic factors is strong in AA, but environmental factors such as infection and psychological stress may still play an important role. Our findings on the genetics of AA are consistent with a polygenic additive mode of inheritance.

Refinement of a locus for Marie Unna hereditary hypotrichosis to a 1.1-cM interval at 8p21.3

BACKGROUND

Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal congenital alopecia with progressive hair loss starting in early childhood and accelerating at puberty. A locus for MUHH has been mapped on chromosome 8p21 but no genes for MUHH have been identified to date.

OBJECTIVES

To refine the MUHH locus to a narrow chromosome region to facilitate cloning of the gene.

METHODS

We performed genotyping and linkage analysis in a multigeneration Chinese family with MUHH, using 18 high-density microsatellite markers spanning the previously mapped interval at 8p21.

RESULTS

Significant evidence for linkage was observed in this region, with a maximum two-point LOD score of 3.01 (theta = 0). Haplotype analysis localized the MUHH locus within the region defined by D8S282 and D8S1839. This region overlaps by 1.1-cM with the previously reported MUHH region and represents a physical distance of about 380 kb.

CONCLUSIONS

This study provides a refined map location (1.1 cM) for isolation of the gene causing MUHH. These data also indicate the existence of a common MUHH locus at 8p21.3 between affected caucasian and Chinese families.

Involvement of bcl-2 and caspase-3 in apoptosis induced by cigarette smoke extract in the gastric epithelial cell

Previous studies have shown that short-term passive cigarette smoking can increase apoptosis in rat gastric mucosa. However, the mechanism is not yet defined. Chloroform and ethanol extracts were used to investigate whether cigarette smoke could induce apoptosis in a human gastric epithelial cell line (AGS) as well as the roles of bcl-2, caspase-3, and cytochrome c in this process. AGS cell lines were treated with either chloroform extract (CE) or ethanol extract (EE) for 5 hours, and the level of bcl-2, the activity of caspase-3, and the level of cytosolic cytochrome c in these cells were determined. Time course studies on the effects of cigarette smoke extracts (CSEs) on DNA fragmentation and cytochrome c relocalization were also performed. Data showed that only CE induced apoptosis in a dose- and time-dependent manner in AGS cells, along with a decrease of bcl-2 and an increase of caspase-3 activity. Pretreatment with Z-DEVD-FMK (specific inhibitor of caspase-3) dose-dependently blocked the DNA fragmentation induced by the CE. Moreover, CE could time- and dose-dependently increase the level of cytochrome c in the cytoplasm, which might activate caspase-3. In conclusion, CSE triggers apoptosis in AGS cells through the inhibition of bcl-2 and the activation of a mitochondria-related pathway.

Chlamydia pneumoniae infection associated with enhanced MRI spinal lesions in multiple sclerosis

Cerebrospinal fluid (CSF) from 66 patients with multiple sclerosis (MS) and 25 patients with other neurological diseases (OND) were examined for the infection of Chlamydia pneumoniae by culture, polymerase chain reaction (PCR) assay, and determination of antibodies to C. pneumoniae. PCR was positive not only in 9 of 28 (32%) patients with MS but also in 2 patents with inflammatory disorders in 15 (13%) OND controls (p = 0.18). Viable C. pneumoniae was isolated from one patient with MS and one with paraneoplastic encephalomyelitis. C. pneumoniae could be detected only in cell-containing CSF. In MS, enhanced spinal magnetic resonance imaging (MRI) lesions were detected in all of four PCR-positive patents but none of five PCR-negative patients, and the difference was significant (p = 0.0079). However, no correlation was found between enhanced brain MRI lesions and CSF C. pneumoniae DNA. Elevated titers of anti-C. pneumoniae IgG were detected in CSF in 13 of 66 (20%) patients with MS and 1 of 25 (4%) OND controls (p = 0.064). CNS C. pneumoniae infection is not uncommon in MS as well as in other inflammatory disorders of the nervous system. The association of active spinal lesions with Chlamydia in CSF collected by lumber puncture suggests the detection of a recent infection. On the other hand, the lack of association of active MS brain lesions with CSF Chlamydia and the presence of PCR-positive patents who are clinically stable and have no enhancing MRI lesions imply the existence of a chronic infectious process.

Expression of liver cancer associated gene HCCA3

AIM: To study and clone a novel liver cancer related gene, and to explore the molecular basis of liver cancer genesis.

METHODS: Using mRNA differential display polymerase chain reaction (DDPCR), we investigated the difference of mRNA in human hepatocellular carcinoma (HCC) and paired surrounding liver tissues, and got a gene probe. By screening a human placenta cDNA library and genomic homologous extend, we obtained a full-length cDNA named HCCA3. We analyzed the expression of this novel gene in 42 pairs of HCC and the surrounding liver tissues, and distribution in human normal tissues by means of Northern blot assay.

RESULTS: A full-length cDNA of liver cancer associated gene HCCA3 has been submitted to the GeneBank nucleotide sequence databases (Accession No. AF276707). The positive expression rate of this gene was 78.6% (33/42) in HCC tissues, and the clinical pathological data showed that the HCCA3 was closely associated with the invasion of tumor capsule (P = 0.023) and adjacant small metastasis satellite nodules lesions (P = 0.041). The HCCA3 was widely distributed in the human normal tissues, which was intensively expressed in lungs, brain and colon tissues, while lowly expressed in the liver tissues.

CONCLUSION: A novel full-length cDNA was cloned and differentiated, which was highly expressed in liver cancer tissues. The high expression was closely related to the tumor invasiveness and metastasis, that may be the late heredited change in HCC genesis.