Liver abscess secondary to an endoscopic tattoo in the colon.

Introduction Endoscopic tattooing of colonic lesions has been used safely for their localization. CASE HISTORY We report a 61-year-old female who had left hemicolectomy in 2006 for adenocarcinoma of the left colon (pT3, pN0, M0). Cancer in the transverse colon was discovered during annual colonoscopy surveillance. The lesion was tattooed 5cm proximal to the lesion. Twenty-four days after tattooing, she was admitted to the emergency department with increased levels of inflammatory markers. CT showed an abscess in the left lobe of the liver adjacent to the tattoo site. The abscess was drained under ultrasound guidance. She had antibiotic treatment for 3 weeks and made a full recovery. CONCLUSION Endoscopic tattooing of colonic lesions is safe but this case report highlights the possibility of a rare (but serious) complication that must be taken into consideration.

Communication: On the stability of ice 0, ice i, and I(h).

Using ab initio methods, we examine the stability of ice 0, a recently proposed tetragonal form of ice implicated in the homogeneous freezing of water [J. Russo, F. Romano, and H. Tanaka, Nat. Mater. 13, 670 (2014)]. Vibrational frequencies are computed across the complete Brillouin Zone using Density Functional Theory (DFT), to confirm mechanical stability and quantify the free energy of ice 0 relative to ice I(h). The robustness of this result is tested via dispersion corrected semi-local and hybrid DFT, and Quantum Monte-Carlo calculation of lattice energies. Results indicate that popular molecular models only slightly overestimate the stability of ice zero. In addition, we study all possible realisations of proton disorder within the ice zero unit cell, and identify the ground state as ferroelectric. Comparisons are made to other low density metastable forms of ice, suggesting that the ice i structure [C. J. Fennel and J. D. Gezelter, J. Chem. Theory Comput. 1, 662 (2005)] may be equally relevant to ice formation.

Challenges in modelling the reaction chemistry of interstellar dust.

Studies aiming to understand the physicochemical properties of interstellar dust and the chemical reactions that occur on and in it have traditionally been the preserve of astronomical observation and experimental attempts to mimic astronomically relevant conditions in the laboratory. Increasingly, computational modelling in its various guises is establishing a complementary third pillar of support to this endeavour by providing detailed insights into the complexities of interstellar dust chemistry. Inherently, the basis of computational modelling is to be found in the details (e.g. atomic structure/composition, reaction barriers) that are difficult to probe accurately from observation and experiment. This bottom-up atom-based theoretical approach, often itself based on deeper quantum mechanical principles, although extremely powerful, also has limitations when systems become too large or complex. In this Perspective, after first providing a general background to the current state of observational-based knowledge, we introduce a number of computational modelling methods with reference to recent state-of-the-art studies, in order to highlight the capabilities of such approaches in this field. Specifically, we first outline the use of computational chemistry methods for dust nucleation, structure, and individual reactions on bare and icy dust surfaces. Later, we review kinetic modelling of networks of reactions relevant to dust chemistry and how to take into account quantum tunnelling effects in the low temperature reactions in the interstellar medium. Finally, we point to the future challenges that need to be overcome for computational modelling to provide even more detailed and encompassing perspectives on the nature and reaction chemistry of interstellar dust.

Evidence for layer-specific differences in auditory corticocollicular neurons.

Recent data suggest that there may be distinct processing streams emanating from auditory cortical layers 5 and 6 that influence the auditory midbrain. To determine whether these projections have different physiological properties, we injected rhodamine-tagged latex tracer beads into the inferior colliculus of >30-day-old mice to label these corticofugal cells. Whole-cell recordings were performed on 62 labeled cells to determine their basic electrophysiological properties and cells were filled with biocytin to determine their morphological characteristics. Layer 5 auditory corticocollicular cells have prominent I(h)-mediated sag and rebound currents, have relatively sluggish time constants, and can generate calcium-dependent rhythmic bursts. In contrast, layer 6 auditory corticocollicular cells are non-bursting, do not demonstrate sag or rebound currents and have short time constants. Quantitative analysis of morphology showed that layer 6 cells are smaller, have a horizontal orientation, and have very long dendrites (>500 µm) that branch profusely both near the soma distally near the pia. Layer 5 corticocollicular cells are large pyramidal cells with a long apical dendrite with most branching near the pial surface. The marked differences in physiological properties and dendritic arborization between neurons in layers 5 and 6 make it likely that each type plays a distinct role in controlling auditory information processing in the midbrain.

Large variation of vacancy formation energies in the surface of crystalline ice.

Resolving the atomic structure of the surface of ice particles within clouds, over the temperature range encountered in the atmosphere and relevant to understanding heterogeneous catalysis on ice, remains an experimental challenge. By using first-principles calculations, we show that the surface of crystalline ice exhibits a remarkable variance in vacancy formation energies, akin to an amorphous material. We find vacancy formation energies as low as ~0.1-0.2 eV, which leads to a higher than expected vacancy concentration. Because a vacancy's reactivity correlates with its formation energy, ice particles may be more reactive than previously thought. We also show that vacancies significantly reduce the formation energy of neighbouring vacancies, thus facilitating pitting and contributing to pre-melting and quasi-liquid layer formation. These surface properties arise from proton disorder and the relaxation of geometric constraints, which suggests that other frustrated materials may possess unusual surface characteristics.

Improving the early presentation of cancer symptoms in disadvantaged communities: putting local people in control.

BACKGROUND AND AIMS: Premature deaths from cancer affect deprived communities disproportionately. The Department of Health has funded a programme in 19 Spearhead PCTs, delivered by the Improvement Foundation, to promote the early presentation and diagnosis of breast, bowel and lung cancers, with the ultimate intention of improving outcomes. METHODS: The programme uses improvement methodology and is a unique approach involving local people working in partnership in their communities to raise awareness of cancer symptoms and promote early presentation. The teams work with primary care, other statutory organisations and with the voluntary sector. The specific contribution of the local people has been in the identification of hard-to-reach groups and the tailoring of effective health messages. RESULTS: Interim results show an increase in the number of urgent 2-week referrals and the proportion of new cancer cases diagnosed through the urgent 2-week referral route (from 43% to 51%) for all three cancers. These results were statistically significant for the bowel cancer and lung cancer pathways. There was also an increase in the proportion with no spread at the time of diagnosis for bowel cancer (38-43%) and breast cancer (41-44.5%), but these results did not reach statistical significance. DISCUSSION: This programme, helping community volunteers to lead work on raising awareness and promotion of earlier presentation of cancer symptoms in partnership with primary care and other professionals, is delivering positive early results.

The phase diagram of water at negative pressures: virtual ices.

The phase diagram of water at negative pressures as obtained from computer simulations for two models of water, TIP4P/2005 and TIP5P is presented. Several solid structures with lower densities than ice Ih, so-called virtual ices, were considered as possible candidates to occupy the negative pressure region of the phase diagram of water. In particular the empty hydrate structures sI, sII, and sH and another, recently proposed, low-density ice structure. The relative stabilities of these structures at 0 K was determined using empirical water potentials and density functional theory calculations. By performing free energy calculations and Gibbs-Duhem integration the phase diagram of TIP4P/2005 was determined at negative pressures. The empty hydrates sII and sH appear to be the stable solid phases of water at negative pressures. The phase boundary between ice Ih and sII clathrate occurs at moderate negative pressures, while at large negative pressures sH becomes the most stable phase. This behavior is in reasonable agreement with what is observed in density functional theory calculations.

Bubbles and microporous frameworks of silicon carbide.

We report the results of density functional theory calculations on nanostructures of SiC, including single clusters, cluster dimers, and nanoporous cluster frameworks. Our results show that at the nanoscale, there is significant charge transfer of 2.5|e| from Si to C atoms, which results in the adoption of the same structural motifs for nanoparticles of SiC that occur for ZnO, with clusters of T(h), T(d), and O symmetry. Experimental support for our models is provided by comparison of optical gaps and ionisation potentials. With the exception of the (SiC)(28) cluster, the T(h) or T(d) nanoparticles can bind into kinetically stable agglomerates on either tetragonal or hexagonal faces, with tetragonal binding energetically preferred for larger nanoclusters, which enables the construction of cubic nanoporous frameworks of varying porosities. Frameworks composed of larger clusters are softer; with bulk moduli of ca. 20 GPa while frameworks assembled from smaller clusters tend to be harder. The electronic structure of all frameworks can be analysed in terms of the adopted short-range order of the clusters, we predict that frameworks containing topological features similar to the rock-salt phase are metallic in nature.

On thin ice: surface order and disorder during pre-melting.

The effect of temperature on the structure of the ice Ih (0001) surface is considered through a series of molecular dynamics simulations on an ice slab. At relatively low temperatures (200 K) a small fraction of surface self-interstitials (i.e. admolecules) appear that are formed exclusively from molecules leaving the outermost bilayer. At higher temperatures (ca. 250 K), vacancies start to appear in the inner part of the outermost bilayer exposing the underlying bilayer and providing sites with a high concentration of dangling hydrogen bonds. Around 250-260 K aggregates of molecules formed on top of the outermost bilayer from self-interstitials become more mobile and have diffusivities approaching that of liquid water. At approximately 270-280 K the inner bilayer of one surface noticeably destructures and it appears that at above 285 K both surfaces are melting. The observed disparity in the onset of melting between the two sides of the slab is rationalised by considering the relationship between surface energy and the spatial distribution of protons at the surface; thermodynamic stability is conferred on the surface by maximising separations between dangling protons at the crystal exterior. Local hotspots associated with a high dangling proton density are suggested to be susceptible to pre-melting and may be more efficient at trapping species at the external surface than regions with low concentrations of protons thus potentially helping ice particles to catalyse reactions. A preliminary conclusion of this work is that only about 10-20 K below the melting temperature of the particular water potential employed is major disruption of the crystalline lattice noted which could be interpreted as being "liquid", the thickness of this film being about a nanometre.

Pseudomyxoma peritonei: a rare presentation as an umbilical nodule.

BACKGROUND: Umbilical nodules are rare and may be the sole presenting sign of an advanced intra-abdominal malignancy associated with poor prognosis. Metastatic involvement of umbilicus was first described in 1846 by Sister Mary Joseph, who established the correlation between carcinomas and umbilical nodes. AIM: We aim to describe a case report of Pseudo Myxoma Peritonei in a 31-year-old man who presented with subcutaneous non tender umbilical nodule. We also aim to emphasize the importance of differential diagnosis, when one encounters the presence of mucoid material in unusual sites such as the umbilicus. METHOD: Patient's clinical notes, operative findings, imaging studies, laboratory investigations including histopathology and immunohistochemistry were reviewed. A literature search was done to look into the incidence, pathophysiology, presentation and treatment options for this neoplastic process. CONCLUSION: PMP should be considered as one of the differential diagnosis when one encounters mucinous collection in unusual sites such as the umbilicus.

Validation of a semi-quantitative adolescent food frequency questionnaire applied at a public school in São Paulo, Brazil.

OBJECTIVE: To develop a food frequency questionnaire for adolescents (AFFQ) and demonstrate its relative validity. DESIGN: The final version of the AFFQ was composed of 76 food items previously identified according to their contribution in nutrients and overall importance within the eating habits of this population group. The validation study, which was undertaken during a 6 month period (June to November 1999), was administered to a sample of 79 who answered at least three 24 h dietary recalls (R24 h) applied at intervals of 45 days and one AFFQ at the end of the study. Applying the paired t-test and calculating Pearson correlation coefficients on nutrient data, differences in the mean of nutrients were obtained. Correlation coefficients between the mean energy-adjusted nutrients computed by the two methods were calculated, and correction was made for within-person variability. Agreement was evaluated by distribution of the adolescents according to quartiles of consumption. LOCUS: A public school within the metropolitan region of São Paulo city. RESULTS: A high variability in the dietary intake of adolescents was observed, with high rates of variability for cholesterol, retinal and vitamin C. The Pearson correlation coefficients, after being adjusted and corrected for variability, ranged from 0.10 to 0.72 among females and from 0.16 and 0.91 among males. The mean correlation coefficient for the entire group was 0.52. CONCLUSIONS: These results indicate that the AFFQ provides a potentially reliable scale for categorizing individuals by level of past intake of most nutrients, excluding retinol and iron.

Detection of arboviral RNA directly from mosquito homogenates by reverse-transcription-polymerase chain reaction.

Many arthropod-borne viruses (arboviruses) are important human pathogens medically. The development of an effective technique to detect the viruses by using nucleic acid amplification, such as polymerase chain reaction (PCR), improves not only clinical diagnosis but also virologic surveillance of mosquito vectors in the field. In this study, the development of an improved and simplified assay is described for detection of mosquitoes infected with eastern equine encephalitis (EEE) virus, Cache Valley (CV), and California (CAL) serogroup viruses from field-collected mosquito pools. As little as 5 microl of homogenate from mosquito pools was used in the reverse transcription (RT) reaction followed by the use of three sets of specific primers for the PCR. Positive pools were determined by finding PCR bands of the expected size for each arbovirus. The confirmation and identification of Bunyaviruses was done by sequencing the PCR product. In 1999, West Nile virus (WNV) was identified as the etiologic agent of an outbreak of human encephalitis in New York City. It is shown that this protocol is also able to detect West Nile viral RNA in a pool of 100 mosquitoes containing one infected mosquito.

The discovery of RPR 200765A, a p38 MAP kinase inhibitor displaying a good oral anti-arthritic efficacy.

RPR132331, a 2-(2-dioxanyl)imidazole, was identified as an inhibitor of tumour necrosis factor (TNF)alpha release from lipopolysaccharide (LPS)-stimulated human monocytes. An intensive programme of work exploring the biology, toxicity and physical chemistry of a novel series of inhibitors, derived from RPR132331, has led to the identification of RPR200765A, a development candidate for the treatment of rheumatoid arthritis (RA). RPR200765A is a potent and selective inhibitor of p38 MAP kinase (IC50 = 50 nM). It inhibits LPS-stimulated TNFalpha release both in vitro, from human monocytes (EC50 = 110 nM), and in vivo in Balb/c mice (ED50 = 6 mg/kg). At oral doses between 10 and 30 mg/kg/day it reduces the incidence and progression in the rat streptococcal cell wall (SCW) arthritis model when administered in either prophylactic or therapeutic dosing regimens. The compound, which is a mesylate salt and exists as a stable monohydrate, shows good oral bioavailabiltiy (F = 50% in the rat) and excellent chemical stability. The data from the SCW disease model suggests that RPR200765A could exhibit a profile of disease modifying activity in rheumatoid arthritis (RA) patients which is not observed with current drug therapies.

Abnormalities in the contractile properties of colonic smooth muscle in idiopathic slow transit constipation.

BACKGROUND: The underlying pathophysiology of idiopathic slow transit constipation (ISTC) remains unclear. At present, there is little evidence to implicate a smooth muscle myopathy in the aetiology of this condition. This study compared the effect of cisapride on the cholinergic response of colonic muscle strips from patients with this condition with that of control tissue. METHODS: Isometric tension production was recorded from circular smooth muscle strips taken from five patients undergoing colectomy for ISTC in response to cumulative concentrations of carbachol (100 nmol/1-100 mumol/l) alone and in the presence of cisapride 400 nmol/l. Similar dose-response activity was obtained for a control group consisting of six patients undergoing resection for colorectal carcinoma. RESULTS: In the absence of cisapride, smooth muscle from patients with carcinoma exhibited a significantly lower sensitivity to cholinergic stimulation (agonist concentration required to produce half-maximal activation (EC50) 4.83 mumol/l) than that from patients with ISTC (EC50 1.63 mumol/l, P = 0.036), and also a greater maximal frequency of the oscillatory activity associated with the increase in isometric tension (0.070 versus 0.049 Hz, P = 0.035). Cisapride had no effect on the sensitivity to carbachol of the carcinoma tissue but brought about a significant reduction in the sensitivity of smooth muscle from patients with ISTC (EC50 3.24 mumol/l, P = 0.043). CONCLUSION: These findings indicate that colonic smooth muscle from patients with ISTC is hypersensitive to cholinergic stimulation and suggest the existence of a smooth muscle myopathy in this condition.

Rectal hypersensitivity in the irritable bowel syndrome.

Studies of rectal sensory thresholds and compliance in patients with the irritable bowel syndrome have produced conflicting results though there is persistent evidence of rectal hypersensitivity particularly in those with diarrhoea-predominant symptoms. This study examined rectal sensation and compliance in 31 patients with constipation-predominant irritable bowel syndrome (mean age 41 years, 27 female) and 17 healthy volunteers (mean age 45 years, 17 female). A rectal balloon was inflated with fluid at a constant rate and the volume and intrarectal pressure at sensory threshold was recorded. The volumes at first (129 +/- 8 vs 229 +/- 24 ml, P < 0.001 Mann-Whitney-U test), constant (159 +/- 12 vs 286 +/- 21, P < 0.001) and maximum tolerated sensation (290 +/- 13 vs 509 +/- 19, P < 0.001) were all significantly less in the irritable bowel group. There was no significant difference in intrarectal pressures at any of these volumes (29.0 +/- 2.2 cmH2O vs 29.0 +/- 2.5, 35.0 +/- 2.5 vs 34.0 +/- 2.8, 71 +/- 2.5 vs 65.0 +/- 3.0 respectively). Rectal compliance was significantly less in the irritable bowel group (3.6 +/- 0.2 ml/cmH2O vs 8.7 +/- 0.4, P < 0.001). Twenty two patients complained of abdominal pain on balloon inflation, mimicking that experienced as part of their symptoms. Patients with constipation-predominant irritable bowel syndrome have rectal hypersensitivity and reduced compliance.

Electronic clinical trial protocol distribution via the World-Wide Web: a prototype for reducing costs and errors, improving accrual, and saving trees.

Clinical trials today typically are inefficient, paper-based operations. Poor community physician awareness of available trials and difficult referral mechanisms also contribute to poor accrual. The Physicians Research Network (PRN) web was developed for more efficient trial protocol distribution and eligibility inquiries. The Medical University of South Carolina's Hollings Cancer Center trials program and two community oncology practices served as a testbed. In 581 man-hours over 18 months, 147 protocols were loaded into PRN. The trials program eliminated all protocol hardcopies except the masters, reduced photocopier use 59%, and saved 1.0 full-time equivalents (FTE), but 1.0 FTE was needed to manage PRN. There were no known security breaches, downtime, or content-related problems. Therefore, PRN is a paperless, user-preferred, reliable, secure method for distributing protocols and reducing distribution errors and delays because only a single copy of each protocol is maintained. Furthermore, PRN is being extended to serve other aspects of trial operations.