Increased frequency of the k-ras G12C mutation in MYH polyposis colorectal adenomas

Colorectal tumours from MYH polyposis patients display an excess of somatic G : C --> T : A transversions in the adenomatous polyposis coli gene. Here, we identify k-ras mutations in nine out of 54 (16.7%) MYH polyposis tumours. Their presence was associated with increased dysplasia and tubulovillous morphology (P=0.005). G : C --> T : A transversions in k-ras were significantly more frequent in MYH polyposis adenomas than in sporadic or familial adenomatous polyposis-associated tumours (P<or=0.002), and all resulted in a glycine-to-cysteine substitution at codon 12.

Rectal prolapse in autistic children

Rectal prolapse in children is not uncommon, but surgery is rarely indicated. In mentally challenged adults and children, rectal prolapse occurs more frequently than in the general population and often requires surgical intervention in the second to third decade of life. The authors describe 3 children with autism and mental retardation who presented with rectal prolapse at an earlier age than would be anticipated with mental retardation alone. All 3 children required surgical intervention.

A novel approach to a patient with Crohn disease and a high stoma output: a missed opportunity?

The development of stricturing or penetrating behaviour in Crohn disease is influenced by disease location, clinical activity of the disease and smoking habit. The management of inflammatory bowel disease remains unsatisfactory, and the influence of current therapies--immunosuppressants, and especially the novel biological treatment now commonly used in Crohn disease--remains largely unknown. A relatively smaller number of patients receive dietary treatment as well. Physicians' scepticism, under-resourced dietetic departments and patient compliance are the main concerns in considering enteral nutrition. The management of high stomal output in Crohn disease is even more challenging. We report a case of active Crohn disease with high stoma output treated successfully solely with enteral feeding without the need for surgical intervention or administration of potent pharmacotherapy.

Expression and characterisation of recombinant oligomeric envelope glycoproteins derived from primary isolates of HIV-1

The production, purification and characterisation of recombinant gp140 oligomeric envelope glycoproteins derived from six primary isolates of HIV-1 (covering clades A, B, C, D, F and O) are described. Using a Chinese hamster ovary cell expression system, expression levels of between 0.1 and 1 mg/l cell-conditioned culture media were obtained, and purified to >95% by affinity chromatography. A, B, D, F and O clade gp 140s were found to be multimeric, bind to a panel of defined env-specific monoclonal antibodies and interact with CD4 and CXCR4, demonstrating correct folding. Their immunogenicity was confirmed by the generation of high-titre anti-gp140 antibodies in rabbits. The C clade gp140 was incorrectly folded and poorly antigenic. Despite the presence of an unmodified gp120/41 cleavage site, only the B clade gp140 showed significant processing to gp120 and gp41. Each gp140 has a specific pattern of oligomerisation, and varies in its resistance to reducing agents and salt concentration. The binding of gp140 to soluble and cell-surface CD4 and CXCR4 is related to the degree of oligomerisation. The C1 and C5 regions, CD4 binding domain and the epitope defined by the 2G12 monoclonal antibody were well exposed, but the C-terminal region of the extracellular domain of gp41 appears to be occluded by oligomerisation. These reagents have potential as immunogens for use in vaccine development.

Knowledge about breast cancer risk factors and hereditary breast cancer among early-onset breast cancer survivors

Little is known about knowledge levels regarding hereditary breast cancer among breast cancer survivors. This study explored, among women with early-onset breast cancer (<50 years): 1) knowledge regarding breast cancer risk factors and hereditary breast cancer; and 2) differences in knowledge based on risk for hereditary disease. Participants recruited from 34 Virginia hospitals responded to two questionnaires. The Family History Questionnaire assessed risk for hereditary breast cancer. The Knowledge, Attitudes, and Beliefs Questionnaire evaluated knowledge of general breast cancer risk factors and hereditary breast cancer. Of 314 respondents, 273 (87%) returned both questionnaires. A total of 137 (52%) participants met the study's criteria for hereditary breast cancer risk. Most participants knew common breast cancer-associated risk factors, including family history of breast cancer. Only 35% recognized family history of non-breast malignancies as a risk factor for breast cancer. Most participants recognized that prophylactic mastectomy does not eliminate breast cancer risk (63%), that not all women carrying a mutation develop disease (73%), and that men can develop breast cancer (96%). The majority selected 'I don't know' for knowledge of several characteristics of hereditary breast cancer, including: early-onset disease (54%); multifocal or bilateral disease (62%); risk transmission through fathers (58%); association with other cancer types (61%); and male breast cancer (70%). Knowledge regarding hereditary breast cancer did not vary between women with suspected hereditary disease and those with presumed sporadic disease. These data highlight the need for information regarding hereditary breast cancer for early-onset breast cancer survivors.

Probing scattering wave functions close to the nucleus

Recently, three-dimensional imaging of the ejected electrons following 100 MeV/amu C6+ single ionization of helium led to the observation of a new structure not predicted by theory [Nature (London) 422, 48 (2003)]]. Instead of the usual "recoil lobe" centered on the momentum-transfer axis, a ring-shaped structure centered on the beam axis was observed. New measurements at 2 MeV/amu exhibit a similar structure, which is now predicted by theory. We argue that the same theory failed at 100 MeV/amu because the faster projectiles probe distances much closer to the nucleus, where our multiple-scattering model is expected to break down.

A functional genomic analysis of cell morphology using RNA interference

Background

The diversity of metazoan cell shapes is influenced by the dynamic cytoskeletal network. With the advent of RNA-interference (RNAi) technology, it is now possible to screen systematically for genes controlling specific cell-biological processes, including those required to generate distinct morphologies.

Results

We adapted existing RNAi technology in Drosophila cell culture for use in high-throughput screens to enable a comprehensive genetic dissection of cell morphogenesis. To identify genes responsible for the characteristic shape of two morphologically distinct cell lines, we performed RNAi screens in each line with a set of double-stranded RNAs (dsRNAs) targeting 994 predicted cell shape regulators. Using automated fluorescence microscopy to visualize actin filaments, microtubules and DNA, we detected morphological phenotypes for 160 genes, one-third of which have not been previously characterized in vivo. Genes with similar phenotypes corresponded to known components of pathways controlling cytoskeletal organization and cell shape, leading us to propose similar functions for previously uncharacterized genes. Furthermore, we were able to uncover genes acting within a specific pathway using a co-RNAi screen to identify dsRNA suppressors of a cell shape change induced by Pten dsRNA.

Conclusions

Using RNAi, we identified genes that influence cytoskeletal organization and morphology in two distinct cell types. Some genes exhibited similar RNAi phenotypes in both cell types, while others appeared to have cell-type-specific functions, in part reflecting the different mechanisms used to generate a round or a flat cell morphology.

Early outcome and cost-effectiveness of endoscopic versus open carpal tunnel release: a randomized prospective trial

Proponents of endoscopic carpal tunnel release have been advocating the technique for more than 10 years but there is still debate about its efficacy, safety and cost-effectiveness. We have performed a randomized, prospective, blind trial to compare early outcome after single portal endoscopic or open carpal tunnel surgery and to assess the cost-effectiveness of the procedures. There were no significant differences in symptom and functional activity scores, grip strength or anterior carpal pain in the first 3 months. For those in employment, we found a statistically significant difference between the two treatment groups with the endoscopic group returning to work, on average, 8 (95% CI, 2-13 days) days sooner than the open group. This translates into a cost saving to industry. There were no major neurovascular complications in either group. On the basis of these findings, we recommend that endoscopic carpal tunnel release should be considered in the employed as a cost-effective procedure, but perhaps not in the general population as a whole.

Casein kinase ii (protein kinase ck2) regulates serotonin 5-ht(3) receptor channel function in ng108-15 cells

We have used whole-cell recording techniques in the mouse neuroblastoma X rat glioma hybrid NG108-15 cell line to test whether protein kinase CK2 (CK2; also known as casein kinase II) modulates the function of the serotonin 5-HT(3) receptor (5-HT(3)R) channel. The rapid application of 5-HT (50 microM) to NG108-15 cells elicits a 5-HT(3)R-mediated inward current response that rapidly reaches peak amplitude and then desensitizes in the continued presence of agonist. Internal dialysis with CK2 (20 micrograms/ml) via the patch pipette significantly increases the amplitude and decreases the rate of desensitization of the 5-HT(3)R-mediated responses. CK2 that had been heat-inactivated has no effect on either the amplitude or the kinetics of desensitization of the 5-HT(3)R responses. These data suggest that dialysis with protein kinase CK2 significantly enhanced current through the 5-HT(3)R channel, and that CK2 may be an important regulator of 5-HT(3)R channel function in the nervous system, possibly serving to facilitate the 5-HT-induced excitation of the cells.

Role of the ground state in electron-atom double ionization

Recently, absolute measurements have been reported for double ionization of helium by 5.6 keV electron-impact. At this high energy, one would think that the first Born approximation for the interaction of the projectile with the atom would be valid. However, on the basis of a lowest-order implementation of a Faddeev-type approach, Berakdar [Phys. Rev. Lett. 85, 4036 (2000)]] concluded that the approximation was not valid. Here we argue that (i) it is valid at this energy and (ii) the previous discrepancy between calculations in the first Born approximation and the overall magnitude of the measurements was due to a poor description of the ground state.

Mutation screening and LD mapping in the VCFS deleted region of chromosome 22q11 in schizophrenia using a novel DNA pooling approach

We examined whether variation within six genes from the VCFS critical region at 22q11 (DGSC, Stk22A1, DGSI, Gscl, Slc25A1 and Znf74) confers susceptibility to schizophrenia. We screened the exons and flanking intronic sequence of each gene for mutations in 14 individuals with DSM-IV schizophrenia using DHPLC. All polymorphisms identified were characterised and genotyped in a sample of 184 schizophrenics and matched controls, using novel DNA pooling methods. Of the polymorphisms identified, 17 were located within exons, six were within coding sequence, and two were non-synonymous. Pooled genotyping revealed no differences in the allele frequencies for any polymorphism between cases and controls that met our pre-defined criterion (P < or = 0.1). In a complementary approach we also attempted to define the location of a schizophrenia susceptibility locus more precisely by performing association mapping using seven microsatellites spanning the VCFS region with an average inter-marker distance of 450 kb. Conventional chi(2) analysis of genotypes in 368 cases and 368 controls revealed that none of the markers was significantly associated (P < 0.05) with schizophrenia. However, evidence for significant association (P = 0.003) was obtained for D22S944 when alleles were combined. TDT analysis of D22S944 genotyped in a further 278 cases of schizophrenia and their parents failed to find any overall allele-wise significant transmission disequilibrium (chi(2) = 18.3, P = 0.17). However, individual analysis of the alleles revealed that allele 12 was excessively non-transmitted and that this almost reached significance when corrected for multiple alleles (chi(2) = 7.35, P = 0.006, P = 0.078 corrected for 13 alleles).

Mutation screening of the Homer gene family and association analysis in schizophrenia

Homer proteins are a group of proteins that regulate group 1 metabotropic glutamate receptor function. As altered glutamate function has been implicated in many neuro psychiatric disorders, particularly schizophrenia, we have screened all three known Homer genes for sequence variation for use under the candidate gene association paradigm. We found seven SNPs, including three in exons. Of these, none was non-synonymous. Allele frequencies of all the detected SNPs were estimated in DNA pools of 368 schizophrenics and 368 controls. Only one (Homer 1 IVS4 + 18A > G) was associated with schizophrenia in this sample, a finding confirmed by individual genotyping (P = 0.01). However, in our extended sample of 680 cases and 671 controls, the evidence for association diminished (P = 0.05). Our results suggest it is unlikely that sequence variants in the Homer genes contribute to the aetiology of schizophrenia, but the variants we identified are plausible candidates for other neuropsychiatric phenotypes.