Could human papillomaviruses be spread through blood?

The human papillomaviruses (HPVs) are epitheliotropic viruses that require the environment of a differentiating squamous epithelium for their life cycle. HPV infection through abrasion of the skin or sexual intercourse causes benign warts and sometimes cancer. HPV DNA detected in the blood has been interpreted as having originated from metastasized cancer cells. The present study examined HPV DNA in banked, frozen peripheral blood mononuclear cells (PBMCs) from 57 U.S. human immunodeficiency virus (HIV)-infected pediatric patients collected between 1987 and 1996 and in fresh PBMCs from 19 healthy blood donors collected in 2002 to 2003. Eight patients and three blood donors were positive mostly for two subgroups of the HPV type 16 genome. The HPV genome detected in all 11 PBMC samples existed as an episomal form, albeit at a low DNA copy number. Among the eight patients, seven acquired HIV from transfusion (three associated with hemophilia) and one acquired HIV through vertical transmission; this patient also had received a transfusion before sampling. Our data suggest that PBMCs may be HPV carriers and might spread the virus through blood.

Oseltamivir resistance during treatment of influenza A (H5N1) infection

Influenza A (H5N1) virus with an amino acid substitution in neuraminidase conferring high-level resistance to oseltamivir was isolated from two of eight Vietnamese patients during oseltamivir treatment. Both patients died of influenza A (H5N1) virus infection, despite early initiation of treatment in one patient. Surviving patients had rapid declines in the viral load to undetectable levels during treatment. These observations suggest that resistance can emerge during the currently recommended regimen of oseltamivir therapy and may be associated with clinical deterioration and that the strategy for the treatment of influenza A (H5N1) virus infection should include additional antiviral agents.

Quantification of the effect of vaccination on transmission of avian influenza (H7N7) in chickens

Recent outbreaks of highly pathogenic avian influenza (HPAI) viruses in poultry and their threatening zoonotic consequences emphasize the need for effective control measures. Although vaccination of poultry against avian influenza provides a potentially attractive control measure, little is known about the effect of vaccination on epidemiologically relevant parameters, such as transmissibility and the infectious period. We used transmission experiments to study the effect of vaccination on the transmission characteristics of HPAI A/Chicken/Netherlands/03 H7N7 in chickens. In the experiments, a number of infected and uninfected chickens is housed together and the infection chain is monitored by virus isolation and serology. Analysis is based on a stochastic susceptible, latently infected, infectious, recovered (SEIR) epidemic model. We found that vaccination is able to reduce the transmission level to such an extent that a major outbreak is prevented, important variables being the type of vaccine (H7N1 or H7N3) and the moment of challenge after vaccination. Two weeks after vaccination, both vaccines completely block transmission. One week after vaccination, the H7N1 vaccine is better than the H7N3 vaccine at reducing the spread of the H7N7 virus. We discuss the implications of these findings for the use of vaccination programs in poultry and the value of transmission experiments in the process of choosing vaccine.

The viral polymerase mediates adaptation of an avian influenza virus to a mammalian host

Mammalian influenza viruses are descendants of avian strains that crossed the species barrier and underwent further adaptation. Since 1997 in southeast Asia, H5N1 highly pathogenic avian influenza viruses have been causing severe, even fatal disease in humans. Although no lineages of this subtype have been established until now, such repeated events may initiate a new pandemic. As a model of species transmission, we used the highly pathogenic avian influenza virus SC35 (H7N7), which is low-pathogenic for mice, and its lethal mouse-adapted descendant SC35M. Specific mutations in SC35M polymerase considerably increase its activity in mammalian cells, correlating with high virulence in mice. Some of these mutations are prevalent in chicken and mammalian isolates, especially in the highly pathogenic H5N1 viruses from southeast Asia. These activity-enhancing mutations of the viral polymerase complex demonstrate convergent evolution in nature and, therefore, may be a prerequisite for adaptation to a new host paving the way for new pandemic viruses.

Amine oxidase substrates for impaired glucose tolerance correction

Amine oxidases are widely distributed from microorganisms to vertebrates and produce hydrogen peroxide plus aldehyde when catabolizing endogenous or xenobiotic amines. Novel roles have been attributed to several members of the amine oxidase families, which cannot be anymore considered as simple amine scavengers. Semicarbazide-sensitive amine oxidase (SSAO) is abundantly expressed in mammalian endothelial, smooth muscle, and fat cells, and plays a role in lymphocyte adhesion to vascular wall, arterial fiber elastic maturation, and glucose transport, respectively. This latter role was studied in detail and the perspectives of insulin-like actions of amine oxidase substrates are discussed in the present review. Independent studies have demonstrated that SSAO substrates and monoamine oxidase substrates mimic diverse insulin effects in adipocytes: glucose transport activation, lipogenesis stimulation and lipolysis inhibition. These substrates also stimulate in vitro adipogenesis. Acute in vivo administration of amine oxidase substrates improves glucose tolerance in rats, mice and rabbits, while chronic treatments with benzylamine plus vanadate exert an antihyperglycaemic effect in diabetic rats. Dietary supplementations with methylamine, benzylamine or tyramine have been proven to influence metabolic control in rodents by increasing glucose tolerance or decreasing lipid mobilisation, without noticeable changes in the plasma markers of lipid peroxidation or protein glycation, despite adverse effects on vasculature. Thus, the ingested amines are not totally metabolized at the intestinal level and can act on adipose and vascular tissues. In regard with this influence on metabolic control, more attention must be paid to the composition or supplementation in amines in foods and nutraceutics.

A novel strategy to compensate the disadvantages of live vaccine using suicide-gene system and provide better antitumor immunity

Fusing dendritic cells (DCs) with tumor cells is a powerful vaccine to increase tumor immunogenicity. To develop more effective and safer therapeutic vaccine, we fused rat bone marrow-derived DCs with ovarian tumor cell line NuTu-19 modified by suicide gene (HSV1-TK gene) to obtain live vaccine against ovarian cancer. Our data showed that immunization of rats with such live vaccine solicited stronger ovarian tumor-specific cytotoxic T lymphocyte responses and induced immunopreventive and immunotherapeutic effects against parental tumor cells in vivo. Live vaccine could be induced to death after ganciclovir administration in vitro and in vivo. Our researches suggest that live vaccine modified with suicide gene might be effective and controllable in the therapy of ovarian cancer.

[Avian influenza viruses isolated in Japan]

Currently, H5N1 influenza viruses remain a serious public health concern in Asia and now in Europe. We showed that the H5N1 viruses associated with outbreaks of HPAI in chickens in Japan were genotypically closely related to an H5N1 virus isolated from a chicken in China in 2003 (genotype V), but were different from those prevalent in southeastern Asia in 2003-2004 (i.e., genotype Z). H5N1 viruses were also isolated from duck meat imported from China during this routine surveillance in May of 2003. We characterized these H5N1 isolates and found that poultry products contaminated with influenza viruses of high pathogenic potential to mammals are a threat to public health even in countries where the virus is not enzootic and represent a possible source of influenza outbreaks in poultry.

Congenital cystic lung lesions: is surgical resection essential?

Can all congenital cystic lung lesions be treated conservatively, without the need for surgery? Our purpose here is to present the morbidity associated with symptomatic cystic lung lesions which have failed to respond to medical treatment. In the past 8 years, 22 consecutive cystic thoracic lesions were retrospectively assessed for clinical presentation, diagnostic modalities, operative findings, technical tribulations, and outcome. The endpoint was complete cessation of recurrent pneumonia and dysphagia. Age at presentation was 7.7 +/- 2.2 years, with 4 +/- 2 episodes per year of lower respiratory tract infection, which had been treated for the past 2.6 +/- 0.3 years. Cough and dyspnea (100%) were the common symptoms, with episodes of cyanosis occurring in 58%. Other significant clinical presentations were dysphagia (55%), failure to thrive (55%), chest pain (46%), haemoptysis (18%), and pleuritic pain (18%). Definitive growth was seen in 91% of the excised specimens. Preoperative morbidity resulted from intractable pneumonia, dysphagia, and failure to thrive. Surgical excision was curative. All 22 children after resection are thriving, with an absence of pneumonia and dysphagia, with normal ventilation/perfusion scans, at 48 +/- 6 months of follow-up. In conclusion, surgical excision of a symptomatic cystic lung lesion that has not responded to medical treatment is recommended.

Validation of molecular targets in prostate cancer

As prostate cancer is not a single disease, it is important to identify the pivotal pathway in the patient being treated. The molecular environment is the site of current oncological research to define new therapeutic targets for hormone-refractory disease, offering the potential to eventually individualize treatment through stratification of pathways. Targets may be validated either phenotypically (e.g. androgen receptor, cadherin) or functionally (e.g. prostate cancer-specific genes). In addition, several other candidates are potentially suitable, while others await discovery. Important initial steps have been made in the search for prostate cancer stem cells; identifying stem cells and the stromal, hormonal, and other signalling molecules that influence their behaviour would have important implications for managing prostate cancer. Although individual therapeutic pathways might be ineffective in a particular molecular environment, combinations of approaches might be capable of producing synergistic effects. A multimodal approach thus might be the best solution. Determining where best to search for a molecular target, and validating whether the target is associated with a sufficiently aggressive malignant process to justify further study is difficult, but the potential benefits are enormous.

A systematic analytic approach to pandemic influenza preparedness planning

The World Health Organization warns that a flu pandemic is inevitable, and possibly imminent. Barnett and colleagues discuss a tool called the Haddon Matrix that could help in pandemic influenza planning.

Virus Spread Pattern within Infected Chicken Farms using Regression Model: the 2003-2004 HPAI Epidemic in the Republic of Korea

During the 2003-2004 epidemic in Korea, the infection time and within-farm spread pattern of virus were analysed for the highly pathogenic avian influenza (HPAI) outbreak on chicken farms using regression models based on epidemiological data. Mortality observed on a given day had a positive linear association with time after initial infection. HPAI spread more rapidly on farms managed by employees and on farms with larger numbers of chicken houses in use. The disease spread more rapidly among layer chickens than among broilers. Using statistical model, we found that farmers recognize the abnormally high mortality resulting from HPAI approximately 5 days after infection. Without any intervention, entire flocks would die within 12 days of introduction of the HPAI virus to the infected farm.

New genotype of avian influenza H5N1 viruses isolated from tree sparrows in China

The 2004 outbreaks of highly pathogenic avian influenza H5N1 disease in China led to a great poultry loss and society attention. A survey of avian influenza viruses was conducted on tree sparrows (Passer montanus) collected in China in 2004. Four viruses were isolated from free-living tree sparrows. The results of the whole-genome analysis indicated that an H5N1 virus with a new genotype is circulating among tree sparrows. The hemagglutinin and neuraminidase genes of the new genotype were derived from Gs/Gd/96-like viruses and the nuclear protein gene descended from the 2001 genotype A H5N1 viruses, while the other inner genes originated from an unknown influenza virus. In experimental infection, all four viruses were highly pathogenic to chickens but not pathogenic to ducks or mice. The four tree sparrow viruses were different from the 2003 tree sparrow strain (genotype Z) in Hong Kong. The results suggested that H5N1 viruses might be distributed widely in tree sparrows.

Omega-3 fatty acids inhibit an increase of proinflammatory cytokines in patients with active Crohn's disease compared with omega-6 fatty acids

BACKGROUND

Crohn's disease is a chronic inflammatory condition affecting the gastrointestinal tract. Polyunsaturated omega-3 fatty acids given orally may reduce the secretion of proinflammatory cytokines and hereby downregulate the inflammatory process.

AIM

To assess the effects of enteral fatty acids, in the form of Impact Powder (Novartis, Switzerland), as adjuvant therapy to corticosteroid treatment on the proinflammatory and anti-inflammatory cytokine profiles in patients with active Crohn's disease.

METHODS

The proinflammatory and anti-inflammatory cytokines were measured in plasma from 31 patients with active Crohn's disease. Patients were randomized for oral intake of omega-3 fatty acid (3-Impact Powder) or omega-6 fatty acids (6-Impact Powder). Clinical and biochemical markers of inflammation were studied at baseline and after 5 and 9 weeks.

RESULTS

Within the 3-Impact Powder group, no significant changes in concentrations of interleukin-6, interferon-gamma, monocyte chemoattractant protein-1, interleukin-2, interleukin-5 and interleukin-10, whereas a significant differences in concentration of interleukin-1beta and interleukin-4 were observed during therapy. Within the 6-Impact Powder group a significant changes in concentrations of interleukin-1beta, interleukin-6, interferon-gamma, monocyte chemoattractant protein-1, interleukin-2, interleukin-4, interleukin-5 and interleukin-10 were observed.

CONCLUSIONS

The 3-Impact Powder showed immunomodulatory properties and might inhibit an increase of proinflammatory cytokines in contrast to the 6-Impact Powder.

Vaccine strategies to treat lymphoproliferative disorders

Lymphoproliferative disorders, including follicular lymphoma (FL), multiple myeloma (MM) and chronic lymphatic leukaemia (CLL), are slowly progressive malignancies which remain incurable despite advances in therapy. Harnessing the immune system to recognise and destroy tumours is a promising new approach to treating these diseases. Dendritic cells (DC) are unique antigen-presenting cells that play a central role in the initiation and direction of immune responses. DC loaded ex vivo with tumour-associated antigens and administered as a vaccine have already shown promise in early clinical trials for a number of lymphoproliferative disorders, but the need for improvement is widely agreed. Recent advances in the understanding of basic DC biology and lessons from early clinical trials have provided exciting new insights into the generation of anti-tumour immune responses and the design of vaccine strategies. In this review we provide an overview of our current understanding of DC biology and their function in patients with lymphoproliferative disorders. We discuss the current status of clinical trials and new approaches to exploit the antigen presenting capacity of DC to design vaccines of the future.

Complete androgen ablation suppresses prostate stem cell antigen (PSCA) mRNA expression in human prostate carcinoma

BACKGROUND

Prostate stem cell antigen (PSCA) is a recently identified glycosylphosphatidylinositol (GPI)-anchored cell surface protein belonging to the Thy-1/Ly-6 family of cell surface antigens. Prior data in prostate cancers indicated that PSCA is directly regulated by androgens and PSCA expression increases with high-tumor grade, advanced stage, extracapsular invasion, and androgen-independent progression. The effect of complete androgen ablation (CAA) on tumor PSCA mRNA expression has not been elucidated. The purpose of the present study was to investigate the variations in the expression levels of PSCA mRNA before and after CAA, and further evaluate the clinically prognostic value of PSCA in human prostate carcinoma.

MATERIALS AND METHODS

PSCA in situ hybridization (ISH) was performed on the cancerous pretreatment biopsy or transurethral resection of prostate (TURP) tissue of 42 men with primarily organ-confined prostate cancer before CAA, and on their tumor tissue from radical retropubic prostatectomy after CAA with bicalutamide and goserelin acetate for 3 months prior to undergoing radical prostatectomy. Tumor cytoplasmic staining of PSCA mRNA was evaluated by two independent pathologists and the differences of PSCA mRNA expression levels between the samples before and after CAA were analyzed using the Student's t-test. Thirty-six to forty months follow-up studies after radical retropubic prostatectomy were performed and aimed at assessing the correlation of PSCA mRNA expression level with local recurrences or metastases from the cancer.

RESULTS

The percent of cells positive for PSCA mRNA by ISH labeling declined from 67.3% (0-89%)+/-9.4% before CAA to 33.8% (0-92%)+/-7.7% after CAA (P<0.001). Before CAA, 40 of 42 cases (95.2%) were positive for PSCA mRNA labeling, however, after CAA the percentage of positive reactivity of PSCA mRNA was decreased to 27 of 40 cases (67.5%), in which none was found with local recurrences or distant metastases after radical prostatectomy on follow-up. This decline in PSCA mRNA labeling was dependent on the original tumor grade with Gleason score of <or=6: 19.3%+/-4.7%, Gleason score of 7: 38.8%+/-7.2%, and a Gleason score of >or=8: 73.4%+/-13.8% (P<0.05, respectively). The rest 13 cases had the increased percentage of cells positive for PSCA mRNA after CAA, in which 3 cases were found with local recurrences and 4 cases with distant metastases from tumor on follow-up.

CONCLUSIONS

Our data demonstrate that CAA for prostate cancer can suppress PSCA mRNA expression with a tumor grade dependence and the increased expression of PSCA mRNA after CAA may be a clinically adverse predictor for tumor recurrences or distant metastases.

High Resolution Contrast-Enhanced MR Angiography in the Evaluation of Rabbit Carotid Artery

This study compared a high resolution contrast-enhanced MR angiography (MRA) sequence to conventional contrast-enhanced MRA sequence for imaging of rabbit carotid artery. Fifteen rabbits underwent an evaluation using both high resolution contrast-enhanced MRA sequence and conventional contrast-enhanced MRA sequence. Siemens 1.5 Tesla Magnetom Vision system was utilized. The parameters of high resolution sequence were: TR/TE= 6.2/2.0 msec, flip angle 25°, matrix 130×512, pixel size 0.96×0.49 mm, partition thickness 1.58 mm, acquisition time 24 sec. The parameters of conventional sequence were: TR/TE=3.8/1.4 msec, flip angle 35°, matrix 110×256, pixel size 1.48×1.02 mm, partition thickness 2mm, acquisition time 10 sec. Maximum intensity projection (MIP) images were created. Both original single slices and MIP images were used for image quality evaluation. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), distinctness of artery edge, and venous contamination were analyzed for both techniques. Higher average CNR and SNR were obtained with high resolution contrast-enhanced MRA, compared to average CNR and SNR with conventional contrast-enhanced MRA. The differences were statistically significant (P<0.01). The artery edge with high resolution method was more distinct than conventional method. Jugular venous contamination was found in five of 15 cases with high resolution contrast-enhanced MRA and in four of 15 cases with conventional contrast-enhanced MRA. High resolution contrast-enhanced MRA has significant potential for high quality noninvasive vascular imaging. The image quality with high resolution contrast-enhanced MRA sequence is better than conventional contrast-enhanced MRA sequence.

[Male genital tract infection: the point of view of the virologist]

Attention to viral infection of the male genital tract has been renewed over the last 15 years as a result of the prolific ongoing research on AIDS. Epidemiological studies of the virus in sperm and male genital tract contributes to the understanding of STD physiopathology and helps assessing their impact on male fertility. Recent advances in this field have allowed to offer Assisted reproductive techniques to couples with chronic viral infection, under strict and specific protocols. This paper presents an overview of these recent developments.

Gene expression perturbation in vitro--a growing case for three-dimensional (3D) culture systems

Cells grown in vitro are dramatically perturbed by their new microenvironment. Analyses of genome-wide gene expression levels offer a first glance at which genes and pathways are affected in cell lines as compared to their tissues of origins. We have summarized available gene expression data and review how cell lines adapt to in vitro environments, to what degree they express markers of their tissues of origins and discuss how cells grown in three-dimensional (3D) cultures may have more physiological interactions with neighbouring cells and extracellular matrix. We will also discuss the interplay between malignant cells and stroma present in tumours but lacking in cell lines and how these differences might affect gene expression comparisons of cell lines to tumours. A model simulating impact of stromal cells on gene expression profiles is presented. Understanding the transcriptomes of cells grown in 2D and 3D cultures and how they compare to those of in vivo cells are important for improving cell line model systems and for the reconstituting of tissues in vitro.

Glycan microarray analysis of the hemagglutinins from modern and pandemic influenza viruses reveals different receptor specificities

Influenza A virus specificity for the host is mediated by the viral surface glycoprotein hemagglutinin (HA), which binds to receptors containing glycans with terminal sialic acids. Avian viruses preferentially bind to alpha2-3-linked sialic acids on receptors of intestinal epithelial cells, whereas human viruses are specific for the alpha2-6 linkage on epithelial cells of the lungs and upper respiratory tract. To define the receptor preferences of a number of human and avian H1 and H3 viruses, including the 1918 H1N1 pandemic strains, their hemagglutinins were analyzed using a recently described glycan array. The array, which contains 200 carbohydrates and glycoproteins, not only revealed clear differentiation of receptor preferences for alpha2-3 and/or alpha2-6 sialic acid linkage, but could also detect fine differences in HA specificity, such as preferences for fucosylation, sulfation and sialylation at positions 2 (Gal) and 3 (GlcNAc, GalNAc) of the terminal trisaccharide. For the two 1918 HA variants, the South Carolina (SC) HA (with Asp190, Asp225) bound exclusively alpha2-6 receptors, while the New York (NY) variant, which differed only by one residue (Gly225), had mixed alpha2-6/alpha2-3 specificity, especially for sulfated oligosaccharides. Only one mutation of the NY variant (Asp190Glu) was sufficient to revert the HA receptor preference to that of classical avian strains. Thus, the species barrier, as defined by the receptor specificity preferences of 1918 human viruses compared to likely avian virus progenitors, can be circumvented by changes at only two positions in the HA receptor binding site. The glycan array thus provides highly detailed profiles of influenza receptor specificity that can be used to map the evolution of new human pathogenic strains, such as the H5N1 avian influenza.

Transdifferentiation of mesenchymal stem cells into Schwann cell-like myelinating cells

Bone marrow stromal cells (MSC) are multipotent stem cells that differentiate into cells of the mesodermal lineage. Although adult, their differentiation potential is remarkable, and they are able to transdifferentiate. Transdifferentiated cultivated rat MSC (tMSC) changed morphologically into cells resembling typical spindle-shaped Schwann cells (SC) with enhanced expression of LNGF receptor, Krox-20, CD104 and S100beta protein and decreased expression of bone morphogenetic protein receptor-1A compared to untreated rat MSC (rMSC). Transdifferentiation was reversible and repeatable. To evaluate the myelinating capacity, rMSC, tMSC, or SC cultured from male rats were grafted into an autologous muscle conduit bridging a 2-cm gap in the female rat sciatic nerve. The presence of the male-specific SRY gene (as revealed by PCR analysis) and S100 immunoreactivity of pre-labeled tMSC confirmed the presence of the implanted cells in the grafts. Three weeks after grafting, an appropriate regeneration was noted in the SC and in the tMSC groups, while regeneration in the rMSC group and in the control group without any cells was impaired. In contrast to SC, in some cases, single tMSC were able to myelinate more than one axon. Our findings demonstrate that it may be possible to differentiate MSC into therapeutically useful cells for clinical applications.

The effect of endogenous formaldehyde on the rat aorta endothelial cells

Previous studies have demonstrated endogenous formaldehyde (FA) may be involved in endothelial damage, and may be a potential factor of vulnerability of atherosclerosis. However, the mechanism has not been characterized. The present studies examined DNA-protein cross-links (DPC) formation in rat aorta endothelial cells (RAECs) treated with formaldehyde, hydrogen peroxide (H2O2), or formaldehyde with equal molar concentration of H2O2, which is produced with formaldehyde in the body at the same time. Using a K+/SDS precipitation assay for DPC determination, concentration-dependent increases in DPC formation were observed 1.5 h after treatment of RAECs with 0.01-2mM FA, H2O2, or FA with equal molar concentration of H2O2. Time-dependent increases in DPC formation were also observed at 0.5-4 h time point after treatment of RAECs with 0.05 and 0.1mM FA, or 0.1mM FA with H2O2. The DPC levels reduced after treatment with FA and equal molar concentration of H2O2, compared with treatment with FA alone. FA may be less cytotoxic, as FA alone did not affect the cell viability even treating for 4h, until the treatment concentration reached 2mM. However, H2O2, and FA with H2O2 induced significant decreases of cell viability. These studies suggest that FA and H2O2 may injure endothelial cells synergistically, and low concentration of FA (0.05-0.1) may contribute to the endothelial injury in the body during aging.

Proinflammatory cytokine responses induced by influenza A (H5N1) viruses in primary human alveolar and bronchial epithelial cells

Background

Fatal human respiratory disease associated with influenza A subtype H5N1 has been documented in Hong Kong, and more recently in Vietnam, Thailand and Cambodia. We previously demonstrated that patients with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible protein-10). Furthermore, when compared with human influenza virus subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97) (H5N1/97) were more potent inducers of pro-inflammatory cytokines (e.g. tumor necrosis factor-a) and chemokines (e.g. IP-10) from primary human macrophages in vitro, which suggests that cytokines dysregulation may play a role in pathogenesis of H5N1 disease. Since respiratory epithelial cells are the primary target cell for replication of influenza viruses, it is pertinent to investigate the cytokine induction profile of H5N1 viruses in these cells.

Methods

We used quantitative RT-PCR and ELISA to compare the profile of cytokine and chemokine gene expression induced by H5N1 viruses A/HK/483/97 (H5N1/97), A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04) with that of human H1N1 virus in human primary alveolar and bronchial epithelial cells in vitro.

Results

We demonstrated that in comparison to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent inducers of IP-10, interferon beta, RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin 6 (IL-6) in primary human alveolar and bronchial epithelial cells in vitro. Recent H5N1 viruses from Vietnam (H5N1/04) appeared to be even more potent at inducing IP-10 than H5N1/97 virus.

Conclusion

The H5N1/97 and H5N1/04 subtype influenza A viruses are more potent inducers of proinflammatory cytokines and chemokines in primary human respiratory epithelial cells than subtype H1N1 virus. We suggest that this hyper-induction of cytokines may be relevant to the pathogenesis of human H5N1 disease.

Detection of amantadine-resistant variants among avian influenza viruses isolated in North America and Asia

Here, we report the diversity of amantadine-resistant mutants among avian influenza A viruses with pandemic potential (H5, H6, H7, and H9 hemagglutinin subtypes). Drug-resistant variants were not detected among 1979--83 isolates, whereas 31.1% of H5 and 10.6% of H9 strains from Southeast Asia isolated in 2000-04 carried mutations in M2 protein. In North America, resistant variants occurred among H7 viruses only (16.4% of those tested). H6 viruses were amantadine-sensitive. These findings prompt concern regarding the control of pandemic influenza, the possibility that the next pandemic virus will be amantadine-resistant and the need to monitor the use of the drug in poultry.

Evolution of H9N2 influenza viruses from domestic poultry in Mainland China

H9N2 viruses have circulated in domestic poultry in Mainland China since 1994, and an inactivated vaccine has been used in chickens to control the disease since 1998. The present study analyzed 27 H9N2 avian influenza viruses that were isolated from chickens and ducks from 1996 to 2002. Infection studies indicated that most of the viruses replicate efficiently but none of them is lethal for SPF chickens. However, these viruses exhibit different phenotypes of replication in a mouse model. Five viruses, including 4 early isolates and one 2000 isolate, are not able to replicate in mice; 14 viruses replicate to moderate titers in mouse lungs and cause less than 5% weight loss, while other 8 viruses could replicate to high titers in the lungs and 7 of them induce 10-20% weight loss of the mice on day 5 after inoculation. Most of the viruses isolated after 1996 are antigenically different from the vaccine strain that is currently used in China. Three viruses isolated in central China in 1998 are resistant to adamantanes. Phylogenetic analysis revealed that all of the viruses originated from CK/BJ/1/94-like virus and formed multiple genotypes through complicated reassortment with QA/HK/G1/97-, CK/HK/G9/97-, CK/SH/F/98-, and TY/WI/66-like viruses. This study is a description of the previously uncharacterized H9N2 avian influenza viruses recently circulating in chickens and ducks in Mainland China. Our findings suggest that urgent attention should be paid to the control of H9N2 influenza viruses in animals and to the human's influenza pandemic preparedness.

Effect of acupuncture at different meridian acupoints on changes of related factors for rabbit gastric mucosal injury

AIM: To explore the regularity of multi-meridians controlling a same viscus (MMCSV).

METHODS: The rabbit gastric ulcer model was established by ethanol intragastric instillation. Fifty-six rabbits were randomly divided into normal group, model group (MG), model plus acupuncture at Foot Yangming Meridian group (YMG), model plus acupuncture at Foot Taiyin Meridian group (TYG), model plus acupuncture at Foot Shaoyang Meridian group (SYG), model plus acupuncture at Foot Jueyin Meridian group (JYG), model plus acupuncture at Foot Taiyang Meridian group (TYMG), with eight rabbits in each group. Gastric mucosal nitric oxide (NO) and nitric oxide synthase (NOS) were assayed by the nitric acid reductase method, and prostaglandin E2 (PGE2) and epidermal growth factor (EGF) were measured by radioimmunoassay. The comprehensive effects were analyzed by weighing method.

RESULTS: Compared to MG, SYG, JYG and TYMG, the rabbits gastric mucosal injury index (GMII) reduced very significantly in YMG (P<0.01). Compared to MG, the GMII also reduced significantly in TYG (P<0.05). NO, NOS, PGE2 and EGF increased very significantly in YMG (P<0.01). The EGF in YMG also increased significantly than that in TYG compared to those in MG, SYG, JYG and TYMG (P<0.05). The PGE2 and EGF also increased very significantly in TYG than those in MG, JYG and TYMG (P<0.01). While compared to SYG, the NOS increased significantly in TYG (P<0.05). NOS was the highest in YMG (P<0.01), and was higher in TYG than in MG (P<0.01).

CONCLUSION: MMCSV is common. The Foot Yangming Meridian is most closely related to the stomach, followed by Foot Taiyin Meridian, Foot Shaoyang Meridian and Foot Jueyin Meridian. Foot Taiyang Meridian has no correlation with the stomach.

Human infection with an avian H9N2 influenza A virus in Hong Kong in 2003

Avian H9N2 influenza A virus has caused repeated human infections in Asia since 1998. Here we report that an H9N2 influenza virus infected a 5-year-old child in Hong Kong in 2003. To identify the possible source of the infection, the human isolate and other H9N2 influenza viruses isolated from Hong Kong poultry markets from January to October 2003 were genetically and antigenically characterized. The findings of this study show that the human H9N2 influenza virus, A/Hong Kong/2108/03, is of purely avian origin and is closely related to some viruses circulating in poultry in the markets of Hong Kong. The continued presence of H9N2 influenza viruses in poultry markets in southern China increases the likelihood of avian-to-human interspecies transmission.

Roles of nitric oxide in protective effect of berberine in ethanol-induced gastric ulcer mice

AIM

To investigate the protective effects of berberine on ethanol-induced gastric ulcer in mice.

METHODS

Gastric ulcers were induced by oral ingestion of ethanol. Nitric oxide (NO) content was measured, and mRNA expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) were analyzed by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The ulcer index (UI) at 1 h, 2 h, 3 h and 6 h after oral administration of ethanol was 23.8+/-1.4, 23.3+/-2.2, 22.3+/-1.2 and 20.8+/-1.1, respectively. The UI in the berberine-treated groups (5 mg/kg and 50 mg/kg) was less than the control group. The content of NO in the control group was 73.3+/-7.3 microL/L, 94.0+/-9.2 microL/L, 109.6+/-6.4 microL/L and 138.2+/-10.2 microL/L in gastric juice and 5.8+/-1.1 micromol/g protein, 8.3+/-1.1 micromol/g protein, 9.8+/-1.1 micromol/g protein and 11.9+/-1.2 micromol/g protein in gastric tissue at 1 h, 2 h, 3 h and 6 h, respectively, after the oral administration of ethanol. The content of NO in the berberine-treated groups (5 mg/kg and 50 mg/kg) was higher than the control group at 1 h after the oral administration of ethanol (P<0.05), and was lower at 6 h (P<0.05). Analysis by RT-PCR showed that expression of eNOS was inhibited but iNOS expression was enhanced by ethanol. However, the expression of eNOS could be enhanced and iNOS expression could be inhibited by berberine (P<0.01).

CONCLUSION

Berberine could significantly protect gastric mucosa from damage by ethanol. This effect may be related to the increased expression of eNOS mRNA and inhibited expression of iNOS mRNA.

Preparing for the next influenza pandemic: lessons from multinational data

BACKGROUND

In the past decade, avian influenza has made several incursions of increasing scope and virulence into humans. The likelihood of another pandemic is increasing with time. In work recently published, influenza was found to be the principal cause of the increase in mortality in the United States during the winter months. In a companion report, the U.S. national vaccination program was shown to have increased coverage of high risk groups 5-fold from 1980 to 1999, but excess mortality did not decline in any elderly age group. The Multinational Influenza Seasonal Mortality Study has assembled and has begun to mine mortality data from many countries. Early results indicate that the U.S. results extend to other economically developed countries and probably worldwide.

RESULTS

The Multinational Influenza Seasonal Mortality Study data extend the observations of others that there were heralding events that provided advance warning for all of the pandemics of the 20th century. Moreover, in the first year of emergence of A(H3N2) viruses, the 1968-1969 pandemic produced little excess mortality outside of North America. It appears that there were at least 2 variants of the pandemic virus, differing at 1 or more internal gene loci, and that the more virulent form emerged as dominant in the second pandemic season.

CONCLUSIONS

Integrating these findings, it seems clear that the influenza control strategy now used in about 50 countries is less than optimal. While it is likely that there will be more time to react in the pandemic season than previously imagined, an enhancement of the historical strategy is clearly indicated. Furthermore, the vaccine shortage that is presently inevitable suggests that a departure from the historical strategy if calamitous ineffectiveness is to be avoided.

Beneficial pleiotropic actions of melatonin in an experimental model of septic shock in mice: regulation of pro-/anti-inflammatory cytokine network, protection against oxidative damage and anti-apoptotic effects

Septic shock, the most severe problem of sepsis, is a lethal condition caused by the interaction of a pathogen-induced long chain of sequential intracellular events in immune cells, epithelium, endothelium, and the neuroendocrine system. The lethal effects of septic shock are associated with the production and release of numerous pro-inflammatory biochemical mediators including cytokines, nitric oxide and toxic oxygen and nitrogen radicals, together with development of massive apoptosis. As melatonin has remarkable properties as a cytokine modulator, antioxidant and anti-apoptotic agent, the present study was designed to evaluate the possible protective effect of melatonin against LPS-induced septic shock in Swiss mice. We observed that intraperitoneally (i.p.) administered-melatonin (10 mg/kg) 30 min prior, and 1 hr after i.p. LPS injection (0.75 mg/animal) markedly protected mice from the LPS lethal effects with 90% survival rates for melatonin and 20% for LPS-injected mice after 72 hr. The melatonin effect was mediated by modulating the release of pro-/anti-inflammatory cytokine levels, protection from oxidative damage and counteracting apoptotic cell death. Melatonin was able to partially counteract the increase in LPS-induced pro-inflammatory cytokine levels such as tumor necrosis factor-alpha, IL-12 and interferon-gamma at the local site of injection, while it increased the production of the anti-inflammatory cytokine IL-10 both locally and systemically. Furthermore, melatonin inhibited the LPS-induced nitrite/nitrate and lipid peroxidation levels in brain and liver and counteracted the sepsis-associated apoptotic process in spleen. In conclusion, we have demonstrated that melatonin improves the survival of mice with septic shock via its pleiotropic functions as an immunomodulator, antioxidant and anti-apoptotic mediator.

Reversal of experimental colitis disease activity in mice following administration of an adenoviral IL-10 vector

Genetic deficiency in the expression of interleukin-10 (IL-10) is associated with the onset and progression of experimental inflammatory bowel disease (IBD). The clinical significance of IL-10 expression is supported by studies showing that immune-augmentation of IL-10 prevents inflammation and mucosal damage in animal models of colitis and in human colitis. Interleukin-10 (IL-10), an endogenous anti-inflammatory and immunomodulating cytokine, has been shown to prevent some inflammation and injury in animal and clinical studies, but the efficacy of IL-10 treatment remains unsatisfactory. We found that intra-peritoneal administration of adenoviral IL-10 to mice significantly reversed colitis induced by administration of 3% DSS (dextran sulfate), a common model of colitis. Adenoviral IL-10 (Ad-IL10) transfected mice developed high levels of IL-10 (394 +/- 136 pg/ml) within the peritoneal cavity where the adenovirus was expressed. Importantly, when given on day 4 (after the induction of colitis w/DSS), Ad-IL10 significantly reduced disease activity and weight loss and completely prevented histopathologic injury to the colon at day 10. Mechanistically, compared to Ad-null and DSS treated mice, Ad-IL10 and DSS-treated mice were able to suppress the expression of MAdCAM-1, an endothelial adhesion molecule associated with IBD. Our results suggest that Ad-IL10 (adenoviral IL-10) gene therapy of the intestine or peritoneum may be useful in the clinical treatment of IBD, since we demonstrated that this vector can reverse the course of an existing gut inflammation and markers of inflammation.

Characterization of the 1918 influenza virus polymerase genes

The influenza A viral heterotrimeric polymerase complex (PA, PB1, PB2) is known to be involved in many aspects of viral replication and to interact with host factors, thereby having a role in host specificity. The polymerase protein sequences from the 1918 human influenza virus differ from avian consensus sequences at only a small number of amino acids, consistent with the hypothesis that they were derived from an avian source shortly before the pandemic. However, when compared to avian sequences, the nucleotide sequences of the 1918 polymerase genes have more synonymous differences than expected, suggesting evolutionary distance from known avian strains. Here we present sequence and phylogenetic analyses of the complete genome of the 1918 influenza virus, and propose that the 1918 virus was not a reassortant virus (like those of the 1957 and 1968 pandemics), but more likely an entirely avian-like virus that adapted to humans. These data support prior phylogenetic studies suggesting that the 1918 virus was derived from an avian source. A total of ten amino acid changes in the polymerase proteins consistently differentiate the 1918 and subsequent human influenza virus sequences from avian virus sequences. Notably, a number of the same changes have been found in recently circulating, highly pathogenic H5N1 viruses that have caused illness and death in humans and are feared to be the precursors of a new influenza pandemic. The sequence changes identified here may be important in the adaptation of influenza viruses to humans.

Selective upregulation of RB3/stathmin4 by ciliary neurotrophic factor following optic nerve axotomy

In this study, we examined the cellular responses of stathmin-related proteins in the rat retina following optic nerve (ON) axotomy. To examine the distribution of stathmin-related gene products, we performed semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization (ISH) and immunohistochemical analyses. Retrograde labeling using a fluorescein tracer, fluorogold (FG), was used for the identification of retinal ganglion cells (RGCs). RT-PCR and ISH analyses indicated that the expression of RB3 was specifically increased in the ganglion cell layer (GCL) comparing to other members of stathmin-related gene family examined 3 days following the ON axotomy. When brain-derived neurotrophic factor was administrated intravitreously, the induction of RB3 mRNA sustained up to 7 days after axotomy, although the peak induction level was unchanged. In contrast, ciliary neurotrophic factor (CNTF) administration increased the peak level of RB3 mRNA induction significantly at 3 days after axotomy. Immunohistochemistry in combination with the retrograde labeling of axotomized cells by FG revealed that RB3 was increased following axotomy in FG-labeled RGCs. These data suggest that RB3 is the unique response protein in the stathmin-related proteins following ON axotomy and the induced RB3 may play a critical role in the CNTF-induced response on the axotomized RGCs, e.g. axonal regeneration and/or neuroprotection.

Preconditioned hyperbaric oxygenation protects the liver against ischemia-reperfusion injury in rats

Hyperbaric oxygen (HBO) therapy is an effective adjunct in treating ischemia-reperfusion (I/R) injury of brain, small intestine, testis, and crushing extremities. This study was designed to test the hypotheses that preconditioning the rats with HBO could protect the liver against subsequent I/R injury. Daily treatment with one-dose HBO (90 min, 2.5 ATA) was brought about for male Sprague Dawley rats for 1 to 3 days before an I/R injury of liver. Hepatic expression of heat-shock protein 70 (Hsp70), total concentration of glutathione (GSH), activity of catalase, superoxide dismutase (SOD), and serum AST and ALT were estimated before and after HBO, as well as after I/R injury. The results showed that activity of hepatic catalase was decreased by one dose, but not three doses, of HBO as compared with baseline data. However, hepatic Hsp70 expression fluctuated insignificantly. AST and ALT increase less in rats preconditioned with one-dose HBO as compared with those without HBO or with three-dose HBO. Our results showed preconditioning by one-dose HBO protects rat liver against subsequent ischemia-reperfusion injury.

Plasma D-dimer levels show correlation with number of lymph node metastases in patients with esophageal cancer

BACKGROUND

Systemic activation of hemostasis and fibrolysis has been shown to be related to tumor progression in patients with malignancies such as lung cancer and colorectal cancer, but there has been no report of these clotting abnormalities in esophageal cancer. We investigated the clinical importance of measuring plasma levels of D-dimer (DD), which is a marker of the hypercoagulable stage, in preoperative patients with esophageal cancer.

STUDY DESIGN

Preoperative plasma DD levels were measured in 96 patients with primary esophageal cancer who were scheduled for esophagectomy with lymphadenectomy without preoperative treatment at our hospital. Results were correlated with the clinicopathological findings.

RESULTS

Significantly different plasma DD levels were found with respect to histologic T (p = 0.0015), histologic N (p < 0.0001), number of metastatic nodes (p < 0.0001), and histologic stages (p < 0.0001). The number of lymph node metastases (0/1 to 3/4 to 7/8-) was found to have the strongest association with DD level among the significant clinicopathologic factors (Spearman rank correlation 0.591, p < 0.0001). The most useful cut-off level of the plasma DD levels for diagnosis of lymph node metastasis was determined to be 0.4 microg/mL, with specificity and sensitivity for lymph node metastasis being 62.9% and 88.2%, respectively.

CONCLUSIONS

Plasma DD levels are useful for assessing lymph node metastasis in patients with esophageal cancer and should be measured preoperatively.

Anti–Prostate Stem Cell Antigen Monoclonal Antibody 1G8 Induces Cell Death In vitro and Inhibits Tumor Growth In vivo via a Fc-Independent Mechanism

Prostate stem cell antigen (PSCA), a 123-amino acid cell surface glycoprotein, is highly expressed in both local and metastatic prostate cancers as well as in a large proportion of bladder and pancreatic cancers. PSCA overexpression correlates with a high risk of recurrence after primary therapy for prostate cancer. We have reported previously that anti-PSCA monoclonal antibody (mAb) 1G8 inhibits tumor growth, prevents metastasis, and prolongs the survival of mice inoculated with human prostate cancer cell lines and xenografts. The current study was undertaken to elucidate the mechanism of action of anti-PSCA antibody therapy. In particular, we asked whether antitumor activity resulted from recruitment of an immune response or a direct effect on the tumor cell itself. In vitro assays show that both intact 1G8 and F(ab')2 fragments of 1G8 induce prostate cancer cell death. The anti-PSCA antibody-induced cell death is caspase independent and requires antigen cross-linking. These results were confirmed in in vivo models in which both 1G8 and F(ab')2 fragments were able to inhibit prostate tumor formation and growth equally. These results suggest that the anti-PSCA mAb 1G8 acts by a direct, Fc-independent mechanism to inhibit prostate tumor growth both in vitro and in vivo.

Anti-hepatoma effect of arsenic trioxide on experimental liver cancer induced by 2-acetamidofluorene in rats

AIM: To study the anti-hepatoma efficiency of arsenic trioxide (As₂O₃) in the treatment of experimental rat hepatocellular carcinoma (HCC) induced by 2-acetamidofluorene (2-FAA) and to elucidate the possible mechanisms.

METHODS: SD rats (2 mo old) had been fed with 2-FAA for 8 wk to induce HCC, and then they were treated with As₂O₃ or matrine. On d 29, the rats were killed and the liver was weighed and liver tumors were counted. The histological changes of liver tissue were observed under microscope, and the cellular dynamic parameters were studied by flow cytometry. Immunohistochemistry (two-step method) was used to observe the expression of vascular endothelial growth factor (VEGF) and micro-vessel density (MVD) on consecutive sections. The pathological parameters were also analyzed, the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBi), and direct bilirubin (DBi).

RESULTS: The number of liver tumors decreased significantly in groups treated with As₂O₃, especially in medium-dose (1 mg/kg) group (t = 2.80, P<0.01). As₂O₃ caused HCC cell death via apoptosis; necrosis was seen and apoptosis was common when the dose was 1 mg/kg. Proliferation index decreased sharply in medium-dose (1 mg/kg) group (7.87±4.11 vs 24.46±6.49, t = 2087, P<0.01), but not in 0.2 mg/kg group. However, S-phase fraction decreased dramatically in both groups, it reached the bottom level only when the dose was 1 mg/kg compared with control (0.40±0.13 vs 3.01±0.51, t = 2.97, P<0.01), and it was obviously accompanied with accumulation of cells in G0/G1 (G0/G1 restriction). The expressions of VEGF and MVD in medium-dose (1 mg/kg) group were significantly lower than normal saline group (0.63±0.74 vs 2.44±0.88, P<0.05; 15.75±3.99 vs 47.44±13.41, t = 2.80, P<0.01). Compared with normal saline group, medium- and low-dose groups As₂O₃ and matrine lowered the levels of ALT in serum (61.46±9.46, 63.75±20.40, 61.18±13.00 vs 108.98±29.86, t = 2.14, P<0.05), but had no effect on the level of serum AST, TBi, and DBi.

CONCLUSION: As₂O₃ had inhibitory effect on growth of experimental HCC in rats induced by 2-FAA, but had no obvious effect on normal hepatic cells. The mechanisms may involve decrease of cell division, accumulation of cells in G0/G1 phase, apoptosis of tumor cells, and inhibitory effect on angiogenesis through blocking VEGF.

Cancer cell-secreted proteomes as a basis for searching potential tumor markers: nasopharyngeal carcinoma as a model

Nasopharyngeal carcinoma (NPC) is commonly diagnosed late due to its deep location and vague symptoms. To identify biomarkers for early NPC diagnosis, secreted proteomes of two NPC cell lines were analyzed. Proteins in the NPC cell-line cultured media were systematically identified by SDS-PAGE combined with MALDI-TOF MS. Twenty-three proteins were found in cultured media from both NPC cell lines. Among them, fibronectin, Mac-2 binding protein (Mac-2 BP), and plasminogen activator inhibitor 1 (PAI-1) were further confirmed by Western blot analysis. These three proteins were highly expressed in NPC biopsies, but weakly or not expressed in normal nasopharyngeal tissues. The serum levels of the three proteins were significantly higher in NPC patients (n = 46) than in normal controls (n = 47) (p < 0.01). NPC nude mice model (n = 9) also showed elevated levels of serum Mac-2 BP and PAI-1 compared with tumor-free mice (n = 9) (p < 0.01). Systematic analysis of cancer cell-secreted proteomes combined with animal tumor models can be a feasible, convenient strategy for searching multiple potential tumor markers. Furthermore, our work shows that fibronectin, Mac-2 BP, and PAI-1 may be potential markers for diagnosis of NPC.

Dominant Role for Calpain in Thromboxane-Induced Neuromicrovascular Endothelial Cytotoxicity

Thromboxane A(2) (TXA(2)) is an important lipid mediator generated during oxidative stress and implicated in ischemic neural injury. This autacoid was recently shown to partake in this injury process by directly inducing endothelial cytotoxicity. We explored the mechanisms for this TXA(2)-evoked neural microvascular endothelial cell death. Stable TXA(2) mimetics 5-heptenoic acid, 7-[6-(3-hydroxy-1-octenyl)-2-oxabicyclo[2.2.1]hept-5-yl]-[1R-[1alpha,4alpha,5beta(Z),6alpha,(1E,3S)]]-9,11-dedioxy-9alpha,11alpha-methanolpoxy (U-46619) [as well as [1S-[1alpha,2alpha(Z),3beta(1E,3S(*)),4alpha]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.1.1]-hept-2-yl]-5-heptenoic acid; I-BOP] induced a retinal microvascular degeneration in rat pups in vivo and in porcine retinal explants ex vivo and death of porcine brain endothelial cells (in culture). TXA(2) dependence of these effects was corroborated by antagonism using the selective TXA(2) receptor blocker (-)-6,8-difluoro-9-p-methyl-sulfonyl-benzyl-1,2,3,4-tetrahydrocarbazol-1-yl-acetic acid (L670596). In all cases, neurovascular endothelial cell death was prevented by pan-calpain and specific m-calpain inhibitors but not by caspase-3 or pan-caspase inhibitors. Correspondingly, TXA(2) (mimetics) augmented generation of known active m-calpain (but not mu-calpain) form and increased the activity of m-calpain (cleavage of fluorogenic substrate N-succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcoumarin; and of alpha-spectrin into specific fragments) but not of pan-caspase or specific caspase-3 (respectively, using sulforhodamine-Val-Arg-Asp-fluoromethyl ketone and detecting its active 17- and 12-kDa fragments). Interestingly, these effects were phospholipase C (PLC)-dependent [associated with increase in inositol triphosphate and inhibited by PLC blocker 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122)] and required calcium but were not associated with increased intracellular calcium. U-46619-induced calpain activation resulted in translocation of Bax to the mitochondria, loss of polarization of the latter (using potentiometric probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide; JC-1) and in turn release of cytochrome c into the cytosol and depletion of cellular ATP; these effects were all blocked by calpain inhibitors. Overall, this work identifies (specifically) m-calpain as a dominant protease in TXA(2)-induced neurovascular endothelial cell death.

Avian influenza A (H5N1)

Since their reemergence in 2003, highly pathogenic avian influenza A (H5N1) viruses have reached endemic levels among poultry in several southeast Asian countries and have caused a still increasing number of more than 100 reported human infections with high mortality. These developments have ignited global fears of an imminent influenza pandemic. The current knowledge of the virology, clinical spectrum, diagnosis and treatment of human influenza H5N1 virus infections is reviewed herein.

Large-scale sequencing of human influenza reveals the dynamic nature of viral genome evolution

Influenza viruses are remarkably adept at surviving in the human population over a long timescale. The human influenza A virus continues to thrive even among populations with widespread access to vaccines, and continues to be a major cause of morbidity and mortality. The virus mutates from year to year, making the existing vaccines ineffective on a regular basis, and requiring that new strains be chosen for a new vaccine. Less-frequent major changes, known as antigenic shift, create new strains against which the human population has little protective immunity, thereby causing worldwide pandemics. The most recent pandemics include the 1918 'Spanish' flu, one of the most deadly outbreaks in recorded history, which killed 30-50 million people worldwide, the 1957 'Asian' flu, and the 1968 'Hong Kong' flu. Motivated by the need for a better understanding of influenza evolution, we have developed flexible protocols that make it possible to apply large-scale sequencing techniques to the highly variable influenza genome. Here we report the results of sequencing 209 complete genomes of the human influenza A virus, encompassing a total of 2,821,103 nucleotides. In addition to increasing markedly the number of publicly available, complete influenza virus genomes, we have discovered several anomalies in these first 209 genomes that demonstrate the dynamic nature of influenza transmission and evolution. This new, large-scale sequencing effort promises to provide a more comprehensive picture of the evolution of influenza viruses and of their pattern of transmission through human and animal populations. All data from this project are being deposited, without delay, in public archives.

Cyclin D1 protein and CCND1 gene expression in colorectal cancer

AIMS

To report the expression of cyclin D1 protein and its gene in a series of colorectal adenocarcinoma.

METHODS

One hundred and eleven specimens of colorectal carcinomas and adjacent normal colorectal mucosa were investigated by staining with a monoclonal antibody against cyclin D1 and by RT-PCR.

RESULTS

Expression of CCND1 gene was found in 54 out of 111 cases of colorectal cancers, while in normal mucosa the expression of this gene was not observed. Cyclin D1 protein expression was checked in the same group of adenocarcinoma cases. Presence of this protein was observed in 69 cases and for 43 of them also expression of its gene was found. Dependence between the presence of protein and the gene expression was statistically significant (p=0.0002). In the group of cases where CCND1 gene expression was detected, high level of its protein expression was found in 20 cases. The CCND1 gene expression was associated with metastases to lymph nodes (p=0.0181) and also with distant metastasis (p=0.0204).

CONCLUSIONS

The combined measurement of both the gene and its protein product, is an important contribution to the study of molecular markers in histological material.

cAMP-induced PKCzeta activation increases functional CXCR4 expression on human CD34+ hematopoietic progenitors

Chemokines are key regulators of hematopoiesis and host defense. We report here that functional expression of the chemokine receptor CXCR4 on human immature CD34+ hematopoietic progenitors was increased as a result of sustained elevation in cellular cAMP by dbcAMP and prostaglandin E2. This effect of cAMP was specifically mediated by PKCzeta activity. CXCR4 expression and PKCzeta activation by cAMP were decreased after the inhibition of cAMP effector-Rap1 by Spa1 overexpression. Interference with the activation of Rac1, a downstream target of Rap1, prevented the cAMP-induced increase in PKCzeta activity and CXCR4 levels. Functional manifestation of the effects of cAMP-elevating agents revealed an increased ability of human CD34+ cells to transmigrate the bone marrow (BM) endothelial layer and adhere to BM stroma in vitro, and it augmented the homing potential to the BM and spleens of immunodeficient mice in a Rac1- and a PKCzeta-dependent manner. cAMP- and TNFalpha-stimulated pathways converged in PKCzeta-activated CXCR4 expression and MMP-2/MMP-9 secretion. cAMP treatment had a beneficial effect on CD34+ cell survival in a PKCzeta-mediated fashion. Taken together, our data reveal major roles for cAMP-induced PKCzeta activation in signaling governing the motility and development of CD34+ cells.

Incidence of adamantane resistance among influenza A (H3N2) viruses isolated worldwide from 1994 to 2005: a cause for concern

BACKGROUND

Adamantanes have been used to treat influenza A virus infections for many years. Studies have shown a low incidence of resistance to these drugs among circulating influenza viruses; however, their use is rising worldwide and drug resistance has been reported among influenza A (H5N1) viruses isolated from poultry and human beings in Asia. We sought to assess adamantane resistance among influenza A viruses isolated during the past decade from countries participating in WHO's global influenza surveillance network.

METHODS

We analysed data for influenza field isolates that were obtained worldwide and submitted to the WHO Collaborating Center for Influenza at the US Centers for Disease Control and Prevention between Oct 1, 1994, and Mar 31, 2005. We used pyrosequencing, confirmatory sequence analysis, and phenotypic testing to detect drug resistance among circulating influenza A H3N2 (n=6524), H1N1 (n=589), and H1N2 (n=83) viruses.

FINDINGS

More than 7000 influenza A field isolates were screened for specific aminoacid substitutions in the M2 gene known to confer drug resistance. During the decade of surveillance a significant increase in drug resistance was noted, from 0.4% in 1994-1995 to 12.3% in 2003-2004. This increase in the proportion of resistant viruses was weighted heavily by those obtained from Asia with 61% of resistant viruses isolated since 2003 being from people in Asia.

INTERPRETATION

Our data raise concerns about the appropriate use of adamantanes and draw attention to the importance of tracking the emergence and spread of drug-resistant influenza A viruses.

Phylogenetic Analysis of Eight Genes of H9N2 Subtype Influenza Virus: A Mainland China Strain Possessing Early Isolates’ Genes that have been Circulating

H9N2 subtype influenza virus has become worldwide and prevalent in China. Previous studies illustrated that at least three sublineages had been established in terrestrial poultry of Eurasian avian. In this presentation, eight full-length genes of an H9N2 strain, A/Chicken/Shanghai/F/98 (Ck/SH/F/98) were obtained. Sequence analysis and phylogenetic studies were conducted by comparing eight genes with those of all the available H9N2 strains from the GenBank. The results showed that four genes (HA, NA, M and NS genes) of Ck/SH/F/98 were incorporated into the sublineage represented by the early mainland China strain, Ck/BJ/1/94. However, the other four of RNP genes of Ck/SH/F/98 did not show close relationship with those of the three known sublineages' viruses. Therefore, Ck/SH/F/98 was a natural reassortant between different sublineages. In addition, comparison showed that Ck/SH/F/98 could be a putative precursor of a later isolate from southern China, Dk/ST/1605/01, with at least six genes of both closely related, indicating genes of Ck/SH/F/98 and early isolates had ever been circulating. Further comparison in terms of molecular markers of species specificity of HA1 revealed that DK/ST/1605/01 also resembled Ck/SH/F/98 more than a common earlier duck strain. The results supported the idea of two-way transmission between terrestrial and aquatic birds that emphasized the importance to raise concerns on the natural evolution of all the eight genes of H9N2 avian influenza viruses.

Expressions of HSP70 and HSP27 in hepatocellular carcinoma

The heat shock proteins (HSPs) are ubiquitous molecules induced in cells exposed to various stress conditions, including carcinogenesis. The HSP70 and HSP27 among HSPs are of special relevance in human cancer inhibiting apoptosis. The aim of this study is to investigate the expressions of HSP70 and HSP27 in hepatocellular carcinoma (HCC) in association to tumor cell proliferation and apoptosis. We examined the expressions of HSP70 and HSP27 by immunohistochemical staining in 71 cases of HCC, and then related their expressions to clinicopathologic parameters and expressions of p53, Ki-67 and Apotag. HSP70 and HSP27 were frequently stained in the cytoplasm and nuclei of tumor cells, but not in the non-neoplastic hepatocytes. Immunoreactivities of HSP70 and HSP27 were observed in 56.3% and 61.9% of HCCs, respectively. HSP70 immunoreactivity correlated with high Ki-67 labeling indices (LIs) (p=0.0159), large tumor size (p=0.0129), presence of portal vein invasion (p=0.0231), and high tumor stage (p=0.0392). HSP27 immunoreactivity significantly related with the subgroup of HBV-associated HCCs (p=0.0003), but not with the others. Both HSP70 and HSP27 immunoreactivities showed no relation to Apotag LIs or p53 immunoreactivity. In conclusion, expressions of HSP70 and HSP27 may play an important role in hepatocarcinogenesis, and especially HSP70 showed a close relationship to the pathological parameters associated with tumor progression and high Ki-67 LIs. Our results could be additional evidence that HSP70 expressions can contribute to not only hepatocarcinogenesis but also tumor progression by promoting tumor cell proliferation.