Identification and quantitation of mucosal and faecal desulfovibrios using real time polymerase chain reaction.

Background: Desulfovibrios produce sulphide, which is toxic to colonic epithelial cells. These bacteria have previously been linked to ulcerative colitis. Traditional methods of culturing these organisms are slow, and often unreliable, while molecular approaches are either non-quantitative or lack sensitivity.

Systemic antibodies towards mucosal bacteria in ulcerative colitis and Crohn's disease differentially activate the innate immune response.

Background And Aims: The mucosa in ulcerative colitis (UC) is replete with antibody producing plasma B cells and polymorphonuclear leucocytes (PMN). This combination of effector cells requires a crosslinking antigen to evoke an antibody driven PMN inflammatory response via their Fc receptors. The stimulus for activation is thought to be commensal bacteria colonising the gut mucosa.

Metal-protein attenuation with iodochlorhydroxyquin (clioquinol) targeting Abeta amyloid deposition and toxicity in Alzheimer disease: a pilot phase 2 clinical trial.

Background: Alzheimer disease (AD) may be caused by the toxic accumulation of beta-amyloid (Abeta).

Objective: To test this theory, we developed a clinical intervention using clioquinol, a metal-protein-attenuating compound (MPAC) that inhibits zinc and copper ions from binding to Abeta, thereby promoting Abeta dissolution and diminishing its toxic properties.

Methods: A pilot phase 2 clinical trial in patients with moderately severe Alzheimer disease.

Why participate in an Alzheimer's disease clinical trial? Is it of benefit to carers and patients?

Background: We explored carer motivation for seeking participation for a relative in an Alzheimer's disease (AD) clinical drug trial, to assess impressions of the value of trial participation. We also surveyed the carers of patients who did not meet study entry screening criteria to see if our conduct of the screening visit was acceptable and ethical.

Method: A retrospective questionnaire was sent to the carers of 36 randomized participants and 22 carers of patients who did not meet study entry screening criteria for an AD clinical treatment trial.

The role of the C-terminal tail in protease-activated receptor-2-mediated Ca2+ signalling, proline-rich tyrosine kinase-2 activation, and mitogen-activated protein kinase activity.

C-terminal truncation mutants were made to investigate the role of the C-terminus in coupling proteinase-activated receptor-2 (PAR-2) to various signalling pathways. Membrane expression of the delta15, delta34, delta43, and delta34-43 mutants was similar; however, expression of deltatail was lost, as was agonist-mediated internalisation of deltatail, delta43, and delta34-43. Additionally, trypsin and SLIGKV-stimulated [3H]IP accumulation was abrogated in cells transiently expressing delta43 or delta34-43 truncations, but remained unaffected in cells expressing delta34 or delta15.

Degradation of cross-linked and non-cross-linked arabinoxylans by the intestinal microbiota in children.

In humans, nonstarch polysaccharides (NSP), such as arabinoxylans (AX), are not digested in the upper gut and provide fermentable carbon sources for bacteria growing in the large bowel. Despite the ubiquity of AX in nature, the microbiologic and physiologic consequences of AX digestion in the gut are poorly understood. In this study, we investigated the breakdown of ferulic acid-cross-linked AX (AXF) and non-cross-linked AX in children's intestinal microbiotas, using starch as a readily fermentable polysaccharide for comparative purposes.

Hidden diabetes in the UK: use of capture-recapture methods to estimate total prevalence of diabetes mellitus in an urban population.

An early requirement of the UK's Diabetes National Service Framework is enumeration of the total affected population. Existing estimates tend to be based on incomplete lists. In a study conducted over one year in North Liverpool, we compared crude prevalence rates for type 1 and type 2 diabetes with estimates obtained by capture-recapture (CR) analysis of multiple incomplete patient lists, to assess the extent of unascertained but diagnosed cases.

The impact upon extra-pyramidal side effects, clinical symptoms and quality of life of a switch from conventional to atypical antipsychotics (risperidone or olanzapine) in elderly patients with schizophrenia.

Background: Atypical antipsychotics are commonly used in the management of schizophrenia in late life with evidence suggesting they induce lower rates of motor disturbance, but have similar efficacy to conventional antipsychotics. Trials in the elderly have been either retrospective, small, of short duration or of a single-arm design.

Aims: To demonstrate the effects upon motor side-effects, efficacy, safety and quality of life (QOL) of switching elderly patients with schizophrenia from conventional antipsychotics to olanzapine or risperidone.

Regulation of short-chain fatty acid production.

Short-chain fatty acid (SCFA) formation by intestinal bacteria is regulated by many different host, environmental, dietary and microbiological factors. In broad terms, however, substrate availability, bacterial species composition of the microbiota and intestinal transit time largely determine the amounts and types of SCFA that are produced in healthy individuals. The majority of SCFA in the gut are derived from bacterial breakdown of complex carbohydrates, especially in the proximal bowel, but digestion of proteins and peptides makes an increasing contribution to SCFA production as food residues pass through the bowel.

Molecular determinants of the transmission of plant viruses by nematodes.

SUMMARY Understanding the mechanisms of transmission of plant viruses is an important part of devising effective and sustainable strategies to protect crop plants against plant virus diseases. There are many difficulties associated with the study of virus transmission by nematodes, particularly as these vector organisms live below ground in the soil feeding on plant roots and cannot be maintained in pure culture. Nevertheless, with recent advances in molecular cloning techniques many details of the transmission process have begun to be revealed, especially with regard to the virus proteins that are required for successful transmission.

Intestinal bacteria and ulcerative colitis.

Convincing evidence from both animal models and the study of patients with ulcerative colitis (UC) implicates the intestinal microflora in the initiation and maintenance of the inflammatory processes in this condition. Despite this, no specific pathogen has been identified as causal and the disease is widely believed to occur as the result of a genetically determined, but abnormal immune response to commensal bacteria. When compared with healthy people, UC patients have increased levels of mucosal IgG directed against the normal microflora.

Analysis of the involvement of an inducible Arabidopsis RNA-dependent RNA polymerase in antiviral defense.

RNA-dependent RNA polymerases (RdRPs) have been implicated in posttranscriptional gene silencing (PTGS) and antiviral defense. An Arabidopsis RdRP (SDE1/SGS2) has been previously shown to be required for transgene-induced PTGS but has no general role in antiviral defense. On the other hand, we have recently shown that transgenic tobacco deficient in an inducible RdRP (NtRdRP1) activity became more susceptible to both Tobacco mosaic virus and Potato virus X.

Acrokeratosis verruciformis of Hopf is caused by mutation in ATP2A2: evidence that it is allelic to Darier's disease.

Acrokeratosis verruciformis of Hopf is a localized disorder of keratinization affecting the distal extremities. Onset is early in life and the disease is inherited in an autosomal dominant fashion. Although histology of acrokeratosis verruciformis lesions shows no evidence of dyskeratosis, a possible relationship with Darier's disease has long been postulated on the basis of clinical similarity.

Immunogold localization of tobravirus 2b nematode transmission helper protein associated with virus particles.

Transmission of the tobraviruses Tobacco rattle virus (TRV) and Pea early-browning virus (PEBV) by trichodorid vector nematodes requires the viral coat protein (CP) and the 2b protein, a nonstructural protein encoded by RNA2, the smaller of the two viral genomic RNAs. It is hypothesized that the 2b protein functions by interacting with a small, flexible domain located at the C-terminus of the CP, forming a bridge between the virus particle and the internal surface of the vector nematode feeding apparatus. Antibodies specific for the 2b protein of PEBV or TRV did not bind to virus particles that were adsorbed to electron microscope grids and were not able to trap virus particles from extracts of infected plants.

Functional replacement of the tobacco rattle virus cysteine-rich protein by pathogenicity proteins from unrelated plant viruses.

Mutation of the 16K gene encoded by RNA1 of Tobacco rattle virus (TRV) greatly reduced the levels of viral RNA that accumulated in both infected protoplasts and plants, showing that the 16K cysteine-rich protein (CRP) is required for efficient multiplication of TRV. Overexpression of the 16K protein, either from an additional copy of the gene carried on TRV RNA2 or from a PVX vector, led to an increase in the severity of disease symptoms, suggesting that the protein has a role in the pathogenicity of the virus. Mutation of the 16K gene could be overcome by expression from RNA2 of the Cucumber mosaic virus 2b gene, the Soil-borne wheat mosaic virus 19K gene, or the Barley stripe mosaic virus gammab gene, indicating that the proteins encoded by these diverse genes may have similar functions.

Carer impressions of participation in Alzheimer's disease clinical trials: what are their hopes? And is it worth it?

Background: We aimed to assess why carers seek participation for their relatives in clinical trials of Alzheimer's disease (AD) medications, and to assess carer impressions of the value of trial participation.

Method: A retrospective questionnaire was sent to 31 carers of participants in clinical trials for AD conducted at the Mental Health Research Institute and the National Aging Research Institute between January 1997 and December 1999.

Results: Twenty-five questionnaires (81%) were returned, completed to an extent to permit analysis.

Substitution of a single amino acid in the 2b protein of Pea early-browning virus affects nematode transmission.

The 2b protein of Pea early-browning virus (PEBV) is required for transmission of the virus by nematodes. Comparison of the 2b proteins of highly transmissible (TpA56) and poorly transmissible (SP5) isolates of PEBV identified two amino acid substitutions (G90S and G177R) that might be responsible for the poor transmission of isolate SP5. Hybrid viruses were created in which the TpA56 2b protein carried SP5-specific substitutions at residue 90 or 177, and in which the SP5 2b protein carried TpA56-specific substitutions at these positions.

Cowpea mosaic virus 32- and 60-kilodalton replication proteins target and change the morphology of endoplasmic reticulum membranes.

Cowpea mosaic virus (CPMV) replicates in close association with small membranous vesicles that are formed by rearrangements of intracellular membranes. To determine which of the viral proteins are responsible for the rearrangements of membranes and the attachment of the replication complex, we have expressed individual CPMV proteins encoded by RNA1 in cowpea protoplasts by transient expression and in Nicotiana benthamiana plants by using the tobacco rattle virus (TRV) expression vector. The 32-kDa protein (32K) and 60K, when expressed individually, accumulate in only low amounts but are found associated with membranes mainly derived from the endoplasmic reticulum (ER).

Unzipping ion channels.

The functions of ion channels can be regulated by their phosphorylation state. Protein kinases and protein phosphatases tightly control the activity of channels, thereby regulating the flow of ions across cell membranes. Channel proteins and kinases or phosphatases can associate directly or through intermediate adaptor proteins.

Proteinase-activated receptor-2-mediated activation of stress-activated protein kinases and inhibitory kappa B kinases in NCTC 2544 keratinocytes.

In this study we examined the regulation of the stress-activated protein (SAP) kinases and inhibitory kappa B kinases (IKKs) through stimulation of the novel G-protein-coupled receptor proteinase-activated receptor-2 in the human keratinocyte cell line NCTC2544. Trypsin and the peptide SLIGKV stimulated a time-dependent increase in both c-Jun N-terminal kinase and p38 mitogen-activated protein kinase activity. Trypsin also stimulated NF kappa B-DNA binding and the activation of the upstream kinases IKK alpha and -beta.

Proteinase-activated receptors.

Proteinase-activated receptors are a recently described, novel family of seven-transmembrane G-protein-coupled receptors. Rather then being stimulated through ligand receptor occupancy, activation is initiated by cleavage of the N terminus of the receptor by a serine protease resulting in the generation of a new tethered ligand that interacts with the receptor within extracellular loop-2. To date, four proteinase-activated receptors (PARs) have been identified, with distinct N-terminal cleavage sites and tethered ligand pharmacology.

'Worms' that transmit viruses.

Plant-parasitic nematodes transmit viruses that hit hard on global agriculture. Both the nematodes and the viruses they carry persist in the soil for a long time with the only remedy being highly toxic chemicals. Fundamental new research may offer the hope of developing safer control strategies.

Tobravirus 2b protein acts in trans to facilitate transmission by nematodes.

Analysis of RNA2 of TRV PaY4 showed it to be recombinant, carrying 3'-terminal sequences derived from RNA1. Virus produced using an infectious cDNA clone of PaY4 RNA2 was nematode transmissible, demonstrating that natural TRV recombinant isolates are not necessarily defective. Mutations introduced into PaY4 RNA2 showed that the 2b gene, but not the 2c gene, is required for transmission by both Paratrichodorus pachydermus and P.

Toxin synthesis and mucin breakdown are related to swarming phenomenon in Clostridium septicum.

Clostridium septicum is responsible for several diseases in humans and animals. The bacterium is capable of a simple kind of multicellular behavior known as swarming. In this investigation, environmental and physiologic factors affecting growth and swarm cell formation in C.