Silica and oesophageal cancer

The growth of animal cells in culture can be stimulated very powerfully when they are allowed to extend upon a solid surface. In normal fibroblasts, the maximum is reached either on a plane surface with an area of 2500 micron 2 or on a narrow fibre with a length of 250 micron. This growth-stimulating effect of fibres could help to explain how asbestos causes cancer. All asbestiform minerals are complex mixtures of different lengths, but siliceous macrohairs with a uniform length are borne by several species of the grass genus Phalaris. Some of these species are common contaminants of the bread eaten in a part of Iran where oesophageal cancer has an unexplained high incidence. A pure preparation of 200 micron silica fibres from one of these species is a powerful promoter of cancer in the skin of mice. Similar fibres from millet (Seteria italica) are associated with the same disease in China, and plant silica has long been known to be associated the it in South Africa. In addition, a rare thoracic tumour, which normally only occurs after exposure to asbestos, has been detected among sugarcane farmers in the United States and in India; fine silica fibres are liberated into the air during the harvest.

Bevacizumab, a vascular endothelial growth factor (VEGF) specific antibody reduces interstitial fluid pressure (IFP) in human rectal cancer xenograft (HT29) by day 5: Is this evidence for rescheduling its timing relative to chemotherapy?

4043

Background: Interstitial fluid pressure (IFP) of most solid tumours is increased relative to normal tissues; this is thought to be associated with the development of structurally and functionally abnormal blood and lymphatic vessels and interstitial fibrosis. Such interstitial hypertension creates a barrier for tumour transvascular transport, consequently compromising the delivery and efficacy of chemotherapy. We investigated the effect of Bevacizumab on IFP of a human rectal cancer xenograft. Methods: SCID mice bearing subcutaneous HT29 tumours of =8.5 mm diameter received a single dose of 10 mg/kg Bevacizumab intraperitoneally; controls received saline. Tumour IFP was measured in sedated mice (Hypnorm) on days 1, 3 and 5 post injection, using the wick-in-needle technique. Experiments were conducted under Home Office licence and approved by the local ethical committee. Results: Groups of 8 treated and control tumours were examined on days 1, 3 and 5 (n = 48). IFP was significantly lower (p<0.0001) on day 5 in treated than control tumours (mean ± SD 15.1 ± 4.7 cf 36.9 ± 5.6 mm Hg). No significant differences (p>0.05) between treated and control groups were seen on day 1 (31.8 ± 3.5 cf 30.6 ± 3.1 mm Hg) or day 3 (33.4 ± 5.5 cf 31.5 ± 3.2 mm Hg). No data were acquired on day 7 as the tumours ulcerated. Conclusions: Our data show that Bevacizumab causes a significant reduction of tumour IFP, but not until 5 days after treatment. Reduced IFP could augment uptake of cytotoxic drugs into tumour cells, hence timing of Bevacizumab relative to the first dose of chemotherapy could be of critical importance.

No significant financial relationships to disclose.

E-MSD: improving data deposition and structure quality

The Macromolecular Structure Database (MSD) (http://www.ebi.ac.uk/msd/) [H. Boutselakis, D. Dimitropoulos, J. Fillon, A. Golovin, K. Henrick, A. Hussain, J. Ionides, M. John, P. A. Keller, E. Krissinel et al. (2003) E-MSD: the European Bioinformatics Institute Macromolecular Structure Database. Nucleic Acids Res., 31, 458-462.] group is one of the three partners in the worldwide Protein DataBank (wwPDB), the consortium entrusted with the collation, maintenance and distribution of the global repository of macromolecular structure data [H. Berman, K. Henrick and H. Nakamura (2003) Announcing the worldwide Protein Data Bank. Nature Struct. Biol., 10, 980.]. Since its inception, the MSD group has worked with partners around the world to improve the quality of PDB data, through a clean up programme that addresses inconsistencies and inaccuracies in the legacy archive. The improvements in data quality in the legacy archive have been achieved largely through the creation of a unified data archive, in the form of a relational database that stores all of the data in the wwPDB. The three partners are working towards improving the tools and methods for the deposition of new data by the community at large. The implementation of the MSD database, together with the parallel development of improved tools and methodologies for data harvesting, validation and archival, has lead to significant improvements in the quality of data that enters the archive. Through this and related projects in the NMR and EM realms the MSD continues to improve the quality of publicly available structural data.

Vasoactive intestinal peptide impairs leucocyte migration but fails to modify experimental murine colitis

Inflammatory bowel diseases are chronic inflammatory disorders of the gastrointestinal tract. Vasoactive intestinal peptide (VIP) is a neuropeptide with known anti-inflammatory activity. We have demonstrated previously that administration of VIP inhibits leucocyte migration in a murine model of delayed-type hypersensitivity, and anti-inflammatory efficacy is supported by other studies. The aim of this study was to investigate the VIP effects in a murine model of intestinal inflammation. Colitis was induced in BALB/c mice by a 2.5 mg enema of 2,4,6-trinitrobenzenesulphonic acid (TNBS) and the mice were killed on day 7. Mice were administered either a 3-day (therapeutic) or 7-day (prophylactic) constant infusion of VIP by subcutaneously implanted mini-osmotic pumps, or intraperitoneal (i.p.) injection of VIP on alternate days over 7 days. Clinical disease scores, weight changes, histopathology of colon tissues, plasma VIP levels, cytokine levels and chemotaxis of peripheral blood mononuclear cells were evaluated. After administration of TNBS, mice quickly developed severe colitis accompanied by dramatic body weight loss (20% by day 6) and high mortality (30%). Prophylactic treatment using high-dose VIP abrogated leucocyte chemotaxis; however, it failed to ameliorate the weight loss and mortality. Moreover, VIP delivered either by constant infusion or i.p. failed to modify the clinical, histological or cytokine markers of disease. Our studies show that, despite an ability to inhibit chemokine-induced chemotaxis of mononuclear cells, VIP was unable to modulate TNBS-induced colitis. This contrasts with the efficacy of VIP in models of mild inflammatory disease and suggests that VIP is unlikely to provide a useful model for novel anti-IBD therapy.

CCR2 expressing CD4+ T lymphocytes are preferentially recruited to the ileum in Crohn's disease

BACKGROUND AND AIMS

Chemokine receptors are key determinants of leucocyte trafficking. While the chemokine receptor CCR9 and its chemokine ligand CCL25 (TECK) mediate lymphocyte homing to the healthy small intestine, the chemokine receptors important for recruitment during intestinal inflammation are undefined. Animal studies have suggested potential roles for CCR2 and CCR5 in inflammatory bowel disease (IBD). The aim of this study was to understand the role of CCR2 in human IBD.

METHODS

Resections of ileum or colon were obtained from patients undergoing surgery for small bowel Crohn's disease (SBCD; n = 10), Crohn's colitis (n = 5), ulcerative colitis (n = 6), and non-IBD related conditions (control ileum n = 11; control colon n = 11). Expression of CCR2 by lamina propria lymphocytes (LPLs) was determined by both flow cytometry and immunohistochemistry. As a functional correlate, chemotaxis assays using the CCR2 ligand, CCL2 (MCP-1), were performed. Expression of CCR2 by peripheral blood lymphocytes was determined by flow cytometry.

RESULTS

There were greater than 30-fold more CCR2(+) LPLs in SBCD than in control ileum (29.3% (19.9-55.1) v 0.9% (0.4-11.5); p = 0.0007). Specifically, CCR2(+)CD4(+) LPLs were increased (p = 0.002) whereas CCR2(+)CD8(+) LPLs were not. Increased expression included both memory (CD45RO(+); p = 0.005) and naïve (CD45RO(-); p = 0.01) CCR2(+) populations. The increase in CCR2(+) LPLs in SBCD was confirmed by both immunohistochemistry (p = 0.0002) and enhanced chemotactic responses to CCL2. CCR2 expression was not increased in the peripheral blood of patients with SBCD, suggesting ongoing recruitment of the CCR2(+) population to the ileum. In contrast with SBCD, there was no significant increase in CCR2(+) LPLs in Crohn's colitis or ulcerative colitis samples.

CONCLUSIONS

The chemokine receptor CCR2 appears to be an important contributor to accumulation of CD4(+) T lymphocytes in the ileum in small bowel Crohn's disease. Blockade of CCR2 may provide a novel therapeutic alternative.

EMDep: a web-based system for the deposition and validation of high-resolution electron microscopy macromolecular structural information

This paper describes the design and implementation of a Web-based deposition system, EMDep, for macro-molecular volumes determined by electron microscopy and deposited at the European Bioinformatics Institute (EBI) for inclusion in the Electron Microscopy Data Base (EMDB). EMDep is a flexible and portable system (http://www.ebi.ac.uk/msd-srv/emdep/) that allows for the acceptance and validation of data, by an interactive depositor-driven operation. The system takes full advantage of the knowledge and expertise of the experimenters, rather than relying on the database curators, for the complete and accurate description of the structural experiment and its results.

E-MSD: an integrated data resource for bioinformatics

The Macromolecular Structure Database (MSD) group (http://www.ebi.ac.uk/msd/) continues to enhance the quality and consistency of macromolecular structure data in the Protein Data Bank (PDB) and to work towards the integration of various bioinformatics data resources. We have implemented a simple form-based interface that allows users to query the MSD directly. The MSD 'atlas pages' show all of the information in the MSD for a particular PDB entry. The group has designed new search interfaces aimed at specific areas of interest, such as the environment of ligands and the secondary structures of proteins. We have also implemented a novel search interface that begins to integrate separate MSD search services in a single graphical tool. We have worked closely with collaborators to build a new visualization tool that can present both structure and sequence data in a unified interface, and this data viewer is now used throughout the MSD services for the visualization and presentation of search results. Examples showcasing the functionality and power of these tools are available from tutorial webpages (http://www. ebi.ac.uk/msd-srv/docs/roadshow_tutorial/).

Endoscopic dilation of gastroesophageal anastomosis stricture after gastric bypass

BACKGROUND

The management of strictures after gastric bypass procedure using balloon dilation is described.

METHODS

A retrospective review of all dilations performed is presented. Balloon dilators were used, and all strictures were dilated initially up to 12 to 15 mm for 1 min.

RESULTS

The review included 24 patients with a mean age of 42.8 years and a mean body mass index of 49.6. All the patients except one were women. In terms of procedure, 67% required one dilation and 30% required two. In the first 3 months after surgery, 21 patients developed the stricture. Three patients (13%) had leaks. There was no endoscopic appearance suggesting the need for a repeated procedure. All the dilations were successful, and weight loss compared well with that in the rest of the patients.

CONCLUSIONS

A successful technique for the treatment of anastomotic strictures after gastric bypass is presented. Most of the patients required one dilation. Most strictures appeared during the first 3 months after surgery. Female gender and leak may be high risk factors for the development of stricture.

E-MSD: the European Bioinformatics Institute Macromolecular Structure Database

The E-MSD macromolecular structure relational database (http://www.ebi.ac.uk/msd) is designed to be a single access point for protein and nucleic acid structures and related information. The database is derived from Protein Data Bank (PDB) entries. Relational database technologies are used in a comprehensive cleaning procedure to ensure data uniformity across the whole archive. The search database contains an extensive set of derived properties, goodness-of-fit indicators, and links to other EBI databases including InterPro, GO, and SWISS-PROT, together with links to SCOP, CATH, PFAM and PROSITE. A generic search interface is available, coupled with a fast secondary structure domain search tool.

Dolastatin-10 in metastatic melanoma: a phase II and pharmokinetic trial of the California Cancer Consortium

Dolastatin-10 is a novel pentapeptide agent originally isolated from the marine mollusk Dolabella auricularia with a mechanism of antitumor activity that involves the inhibition of microtubule assembly. We performed a Phase II trial of Dolastatin-10, 400 microg/m2 in patients with advanced melanoma who had received no prior chemotherapy. Dolastatin-10 pharmokinetics were evaluated in a subset of patients following courses 1 and 2. Twelve patients were treated with a median of 2 cycles of Dolastatin-10, and no patient experienced an objective response. The only grade >2 toxicities were grade 3 neutropenia uncomplicated by infection, occurring in 4 patients following the first treatment cycle. The total systemic clearance and volume of distribution at steady-state were 2.61 +/- 1.9 L/h/m2 and 28.4 +/- 13 L/m2, respectively. Due to prolonged terminal elimination. Dolastatin-10 plasma concentrations of greater than 1 nM were sustained for 24 h in all patients studied. Dolastatin-10 is unlikely to have substantial activity in the treatment of melanoma.

Diagnosis of influenza in the community: relationship of clinical diagnosis to confirmed virological, serologic, or molecular detection of influenza

BACKGROUND

Successful treatment of influenza depends on an accurate diagnosis of the illness and prompt intervention. However, there is a lack of data comparing clinical diagnosis vs laboratory diagnostic techniques.

OBJECTIVE

To compare the clinical diagnosis of community cases of influenza with various laboratory diagnostic techniques including multiplex, reverse transcription polymerase chain reaction.

METHODS

Clinical diagnosis, viral isolation, hemagglutinin inhibition serology, and multiplex, reverse transcription polymerase chain reaction were used to diagnose influenza in patients enrolled in international phase 3 studies designed to investigate the efficacy and safety of an anti-influenza drug (inhaled zanamivir). Patients clinically diagnosed with influenza were enrolled at centers across North America and Europe.

RESULTS

A total of 791 (77%) of 1033 patients with laboratory results from all 3 methods were confirmed positive for influenza by 1 or more test results. For 692 patients (67%), the results of all 3 tests agreed. Total symptom scores at baseline showed a significant association toward greater severity of symptoms with an increasing number of positive test results (P<.001). An increasing number of positive test results also showed a significant correlation with a longer time to alleviation of symptoms of influenza in the placebo group (P =.001).

CONCLUSIONS

During a time when influenza was known to be circulating and clinical diagnostic criteria were applied, diagnosis of influenza in these trials was accurate in approximately 77% of adults on clinical grounds alone. This highlights the need for primary care physicians to be alerted to circulating influenza and to be aware that presentation with cough and fever provide the most predictive symptoms.

A humanized anti-human CD154 monoclonal antibody blocks CD154-CD40 mediated human B cell activation

Humanized anti-CD154 antibody, IDEC-131, had a slightly, but reproducibly, better binding affinity for CD154 (Kd = 5.6 nM), compared to the parent antibody 24-31 (Kd = 8.5 nM). Otherwise it was indistinguishable from the murine parent antibody in its ability to bind to CD154, block CD154 binding to CD40 and inhibit T cell-dependent B cell differentiation. The latter activity was independent of FcR binding as the Fab'1 fragment of IDEC-131 had an equivalent biological activity to that of the whole antibody. IDEC-131 blocked soluble CD154 from inducing proliferation of purified B cells, and blocked T cell dependent anti-tetanus toxoid specific antibody production by human B cells in vitro. IDEC-131, gamma1, kappa, had strong Fc gammaRI, Fc gammaRII and C1q binding, but was unable to induce complement dependent (CDC) or antibody dependent cell-cytotoxicity (ADCC) of activated peripheral blood T cells, which express relatively low levels of CD154. IDEC-131 antibody inhibited both primary and secondary antibody responses to ovalbumin in cynomolgus monkeys at a dose of 5 mg/kg. In non-immunized animals, treatment with IDEC-131 at 50 mg/kg weekly for 13 weeks induced no change in any of the measured lymphocyte subsets, including B cells, CD4+ and CD8+ T cells. Similarly, a safety study in chimpanzees showed no discernible safety related issues at 20 mg/kg, including B and T cell subsets. These results show that the humanized anti-CD154 antibody, IDEC-131, has retained the affinity and functional activity of its murine parent antibody, is unlikely to deplete CD154 positive lymphocytes in humans, and is safe and effective in blocking antibody production in monkeys. Based on its safety and efficacy profile, IDEC-131 is being developed for therapy of systemic lupus erythematosus.

Loss of the major GABA(A) receptor subtype in the brain is not lethal in mice

The alpha1beta2gamma2 is the most abundant subtype of the GABA(A) receptor and is localized in many regions of the brain. To gain more insight into the role of this receptor subtype in the modulation of inhibitory neurotransmission, we generated mice lacking either the alpha1 or beta2 subunit. In agreement with the reported abundance of this subtype, >50% of total GABA(A) receptors are lost in both alpha1-/- and beta2-/- mice. Surprisingly, homozygotes of both mouse lines are viable, fertile, and show no spontaneous seizures. Initially half of the alpha1-/- mice died prenatally or perinatally, but they exhibited a lower mortality rate in subsequent generations, suggesting some phenotypic drift and adaptive changes. Both adult alpha1-/- and beta2-/- mice demonstrate normal performances on the rotarod, but beta2-/- mice displayed increased locomotor activity. Purkinje cells of the cerebellum primarily express alpha1beta2gamma2 receptors, and in electrophysiological recordings from alpha1-/- mice GABA currents in these neurons are dramatically reduced, and residual currents have a benzodiazepine pharmacology characteristic of alpha2- or alpha3-containing receptors. In contrast, the cerebellar Purkinje neurons from beta2-/- mice have only a relatively small reduction of GABA currents. In beta2-/- mice expression levels of all six alpha subunits are reduced by approximately 50%, suggesting that the beta2 subunit can coassemble with alpha subunits other than just alpha1. Our data confirm that alpha1beta2gamma2 is the major GABA(A) receptor subtype in the murine brain and demonstrate that, surprisingly, the loss of this receptor subtype is not lethal.

Potent in vitro anticancer activities of ring-expanded ("fat") nucleosides containing the imidazo[4,5-e][1,3]diazepine ring system

The ring-expanded ("fat") nucleoside, 4,8-diamino-6-imino-6H-1-beta-D-ribofuranosylimidazo[4,5-e][1,3]diazepine (1) and its 2',3',5'-tri-O-benzoyl derivative (2) exhibited potent broad spectrum anticancer activities in vitro against a wide variety of human tumor cell lines. The tribenzoyl derivative 2 was found to be considerably more active than the parent nucleoside 1. Further studies using human prostate cancer cells PC-3 and DU-145 suggest that the treatment of exponentially growing culture cells with 1 and 2 leads to marked loss of cell viability in a dose-dependent manner.

Percutaneous transpouch management of a ureteral stone and ureteral-pouch stricture in a pelvic kidney

Stones in pelvic kidney collecting systems have not been routinely managed percutaneously in most urologic practices. Especially challenging is the management of stones in a pelvic kidney collecting system positioned posteriorly to a urinary diversion. In the present case, a 32-year-old man with a pelvic kidney and continent urinary diversion presented with fever and hydronephrosis. Drainage of the kidney was obtained percutaneously by way of an anterior approach through-and-through the urinary diversion. The patient was found to have both a ureteral stone and a ureteral-pouch anastomotic stricture on subsequent imaging. We were able to successfully treat both these problems endoscopically through a solitary percutaneous access.

Measurement of protein interaction bioenergetics: application to structural variants of anti-sCD4 antibody

This chapter has described a bioenergetic analysis of the interaction of sCD4 with an IgG1 and two IgG4 derivatives of an anti-sCD4 MAb. The MAbs have identical VH and VL domains but differ markedly in their CH and CL domains, raising the question of whether their antigen-binding chemistries are altered. We find the sCD4-binding kinetics and thermodynamics of the MAbs are indistinguishable, which indicates rigorously that the molecular details of the binding interactions are the same. We also showed the importance of using multiple biophysical methods to define the binding model before the bioenergetics can be appropriately interpreted. Analysis of the binding thermodynamics and kinetics suggests conformational changes that might be coupled to sCD4 binding by these MAbs are small or absent.