Metastasis of Renal Cell Carcinoma to the Stomach Twenty One Years from Initial Diagnosis.

A female in her 80's presented to our Emergency Department following a fall. She reported general malaise, weight loss and raised inflammatory markers. Background included renal cell carcinoma 21 years previous, managed with radical nephrectomy. During her inpatient stay she had an episode of haematemesis. Upper GI endoscopy revealed a 3cm polypoidal lesion on the greater curve of the upper stomach. This had an irregular pit pattern endoscopically and was friable. Multiple biopsies revealed metastatic clear cell carcinoma of renal origin; the same sub-type as her previous renal tumour. This is a rare manifestation of metastatic renal cell carcinoma and from literature review, is only the 2nd case we can find with a lag time of >20 years from the initial diagnosis to presenting with metastatic gastric disease.

Transient structures in rupturing thin films: Marangoni-induced symmetry-breaking pattern formation in viscous fluids.

In the minutes immediately preceding the rupture of a soap bubble, distinctive and repeatable patterns can be observed. These quasistable transient structures are associated with the instabilities of the complex Marangoni flows on the curved thin film in the presence of a surfactant solution. Here, we report a generalized Cahn-Hilliard-Swift-Hohenberg model derived using asymptotic theory that describes the quasielastic wrinkling pattern formation and the consequent coarsening dynamics in a curved surfactant-laden thin film. By testing the theory against experiments on soap bubbles, we find quantitative agreement with the analytical predictions of the nucleation and the early coarsening phases associated with the patterns. Our findings provide fundamental physical understanding that can be used to (de-)stabilize thin films in the presence of surfactants and have important implications for both natural and industrial contexts, such as the production of thin coating films, foams, emulsions, and sprays.

Longitudinal Trends in Quality of Life and Physical Function in Frail Older Dialysis Patients: A Comparison of Assisted Peritoneal Dialysis and In-Center Hemodialysis.

BACKGROUND: In-center hemodialysis (HD) has been the standard treatment for older dialysis patients, but reports suggest an associated decline in physical and cognitive function. Cross-sectional data suggest that assisted peritoneal dialysis (aPD), an alternative treatment, is associated with quality of life (QoL) outcomes that are comparable to in-center HD. We compared longitudinal changes in QoL between modalities. METHODS: We enrolled 106 aPD patients, matched with 100 HD patients from 20 renal centers in England and Northern Ireland. Patients were assessed quarterly for 2 years using the Hospital Anxiety and Depression Scale (HADS), SF-12 physical and mental scores, symptom score, Illness Intrusiveness Rating Scale (IIRS), Barthel's score, and the Renal Treatment Satisfaction Questionnaire (RTSQ). Mixed model analysis was used to assess the impact of dialysis modality on these outcomes during follow-up. P values were adjusted for multiple significance testing. RESULTS: Multivariate analysis showed no difference in any of the outcome measures between aPD and HD. Longitudinal trends in outcomes were also not significantly different. Higher age at baseline was associated with lower IIRS and RTSQ scores during follow-up. One-hundred and twenty-five (60.6%) patients dropped out of the study: 59 (28.6%) died, 61 (29.6%) withdrew during follow-up, and 5 (2.5%) were transplanted. CONCLUSIONS: Quality of life outcomes in frail older aPD patients were equivalent to those receiving in-center HD. Assisted PD is thus a valid alternative to HD for older people with end-stage kidney disease (ESKD) wishing to dialyze at home.

Marangoni effect on small-amplitude capillary waves in viscous fluids.

We derive a general integro-differential equation for the transient behavior of small-amplitude capillary waves on the planar surface of a viscous fluid in the presence of the Marangoni effect. The equation is solved for an insoluble surfactant solution in concentration below the critical micelle concentration undergoing convective-diffusive surface transport. The special case of a diffusion-driven surfactant is considered near the the critical damping wavelength. The Marangoni effect is shown to contribute to the overall damping mechanism, and a first-order term correction to the critical wavelength with respect to the surfactant concentration difference and the Schmidt number is proposed.

Nonequilibrium Molecular Dynamics Simulations of Organic Friction Modifiers Adsorbed on Iron Oxide Surfaces.

For the successful development and application of lubricants, a full understanding of the nanoscale behavior of complex tribological systems is required, but this is difficult to obtain experimentally. In this study, we use nonequilibrium molecular dynamics (NEMD) simulations to examine the atomistic structure and friction properties of commercially relevant organic friction modifier (OFM) monolayers adsorbed on iron oxide surfaces and lubricated by a thin, separating layer of hexadecane. Specifically, acid, amide, and glyceride OFMs, with saturated and Z-unsaturated hydrocarbon tail groups, are simulated at various surface coverages and sliding velocities. At low and medium coverage, the OFMs form liquidlike and amorphous monolayers, respectively, which are significantly interdigitated with the hexadecane lubricant, resulting in relatively high friction coefficients. At high coverage, solidlike monolayers are formed for all of the OFMs, which, during sliding, results in slip planes between well-defined OFM and hexadecane layers, yielding a marked reduction in the friction coefficient. When present at equal surface coverage, OFMs with saturated and Z-unsaturated tail groups are found to yield similar structure and friction behavior. OFMs with glyceride head groups yield significantly lower friction coefficients than amide and particularly carboxylic acid head groups. For all of the OFMs and coverages simulated, the friction coefficient is found to increase linearly with the logarithm of sliding velocity; however, the gradient of this increase depends on the coverage. The structure and friction details obtained from these simulations agree well with experimental results and also shed light on the relative tribological performance of these OFMs through nanoscale structural variations. This has important implications in terms of the applicability of NEMD to aid the development of new formulations to control friction.

A Comparison of Classical Force-Fields for Molecular Dynamics Simulations of Lubricants.

For the successful development and application of lubricants, a full understanding of their complex nanoscale behavior under a wide range of external conditions is required, but this is difficult to obtain experimentally. Nonequilibrium molecular dynamics (NEMD) simulations can be used to yield unique insights into the atomic-scale structure and friction of lubricants and additives; however, the accuracy of the results depend on the chosen force-field. In this study, we demonstrate that the use of an accurate, all-atom force-field is critical in order to; (i) accurately predict important properties of long-chain, linear molecules; and (ii) reproduce experimental friction behavior of multi-component tribological systems. In particular, we focus on n-hexadecane, an important model lubricant with a wide range of industrial applications. Moreover, simulating conditions common in tribological systems, i.e., high temperatures and pressures (HTHP), allows the limits of the selected force-fields to be tested. In the first section, a large number of united-atom and all-atom force-fields are benchmarked in terms of their density and viscosity prediction accuracy of n-hexadecane using equilibrium molecular dynamics (EMD) simulations at ambient and HTHP conditions. Whilst united-atom force-fields accurately reproduce experimental density, the viscosity is significantly under-predicted compared to all-atom force-fields and experiments. Moreover, some all-atom force-fields yield elevated melting points, leading to significant overestimation of both the density and viscosity. In the second section, the most accurate united-atom and all-atom force-field are compared in confined NEMD simulations which probe the structure and friction of stearic acid adsorbed on iron oxide and separated by a thin layer of n-hexadecane. The united-atom force-field provides an accurate representation of the structure of the confined stearic acid film; however, friction coefficients are consistently under-predicted and the friction-coverage and friction-velocity behavior deviates from that observed using all-atom force-fields and experimentally. This has important implications regarding force-field selection for NEMD simulations of systems containing long-chain, linear molecules; specifically, it is recommended that accurate all-atom potentials, such as L-OPLS-AA, are employed.

Predicting mortality and uptake of renal replacement therapy in patients with stage 4 chronic kidney disease.

BACKGROUND: Novel strategies are required to efficiently manage the increasing number of patients diagnosed with chronic kidney disease (CKD). We sought to identify factors predicting outcome in patients with stage 4 CKD and to determine whether low-risk patients could be managed in primary care. METHODS: We performed a two-centre, retrospective cohort study including 396 patients with stage 4 CKD referred to nephrology clinics from 1998 to 2002. We utilized electronic databases to determine the incidence of renal replacement therapy (RRT) and mortality and the rate of deterioration in estimated glomerular filtration rate (eGFR) to the year end 2005. RESULTS: This was an elderly cohort, with 71.7% of patients aged > or =65 years. The risk of surviving to require dialysis fell with increasing age (HR 0.44; 95% CI: 0.23-0.84 for those >74 years verses those <65 years), in part due to the slower rate of decline in renal function in older patients (median fall in eGFR was -2.25, -1.38 and -0.86 ml/ min/1.73 m(2)/year in those aged <65 years, 65-74 years and >74 years, respectively, P < 0.0001). Additional independent risk factors predicting RRT included: high baseline proteinuria (HR 6.26; 95% CI: 2.74-14.23 for >3 g/24 h versus <0.3 g/24 h), greater early decline in renal function (HR 3.86; 95% CI: 2.34-6.38 for > or =4 ml/min/1.73 m(2)/year versus <4 ml/min/1.73 m(2)/year), low baseline eGFR (HR 2.92; 95% CI: 1.61-5.30 for 15-19 versus 25-29 ml/min/1.73 m(2)) and low haemoglobin (HR 3.16; 95% CI: 1.64-6.08 for <10 versus >12 g/dl). The 98 (24.7%) patients discharged to primary care had more stable renal function than those remaining under nephrology care (median change in eGFR of +0.20 versus -1.88 ml/ min/1.73 m(2)/year, P = 0.0001). CONCLUSIONS: Most patients with stage 4 CKD, in particular the elderly, die without commencing RRT. Patients at low risk of progression can be identified and discharged safely to primary care with an active management plan.

Alterations in platelet serotonin transporter binding in women with postpartum onset major depression.

There is considerable debate as to whether postpartum depression (PPD) is biologically distinct from other depressive syndromes. Although abnormalities in serotonergic neural systems have repeatedly been reported in depression, few such studies have been conducted in PPD. In the present study, platelet serotonin transporter (SERT) binding was assessed using [(3)H]paroxetine in 14 depressed pregnant women, 31 normal healthy pregnant women, 39 depressed postpartum women, and 27 normal healthy postpartum women; all of the subjects were drug-free. Significant differences were detected among the 4 groups with respect to the dissociation constant (Kd) of platelet binding sites for [(3)H]paroxetine with the highest Kd values among those with PPD. The density (Bmax) of platelet binding sites for [(3)H]paroxetine did not differ between the study groups. These data suggest that PPD may be associated with unique alterations in serotonergic function that are specific to the puerperium.

AINT/ERIC/TACC: an expanding family of proteins with C-terminal coiled coil domains.

The AINT/ERIC/TACC genes encode novel proteins with a coiled coil domain at their C-terminus. The founding member of this expanding family of genes, transforming acidic coiled coil 1 (TACC1), was isolated from a BAC contig spanning the breast cancer amplicon-1 on 8p11. Transfection of cells in vitro with TACC1 resulted in anchorage-independent growth consistent with a more "neoplastic" phenotype. Database searches employing the human TACC1 sequence revealed other novel genes, TACC2 and TACC3, with substantial sequence homology particularly in the C-terminal regions encoding the coiled coil domains. TACC2, located at 10q26, is similar to anti-zuai-1 (AZU-1), a candidate breast tumour suppressor gene, and ECTACC, an endothelial cell TACC which is upregulated by erythropoietin (Epo). The murine homologue of TACC3, murine erythropoietin-induced cDNA (mERIC-1) was also found to be upregulated by Epo in the Friend virus anaemia (FVA) model by differential display-PCR. Human ERIC-1, located at 4p16.3, has been cloned and encodes an 838-amino acid protein whose N- and C-terminal regions are highly homologous to the shorter 558-amino acid murine protein, mERIC-1. In contrast, the central portions of these proteins differ markedly. The murine protein contains four 24 amino acid imperfect repeats. ARNT interacting protein (AINT), a protein expressed during embryonic development in the mouse, binds through its coiled coil region to the aryl hydrocarbon nuclear translocator protein (ARNT) and has a central portion that contains seven of the 24 amino acid repeats found in mERIC-1. Thus mERIC-1 and AINT appear to be developmentally regulated alternative transcripts of the gene. Most members of the TACC family discovered so far contain a novel nine amino acid putative phosphorylation site with the pattern [R/K]-X(3)-[E]-X(3)-Y. Genes with sequence homology to the AINT/ERIC/TACC family in other species include maskin in Xenopus, D-TACC in Drosophila and TACC4 in the rabbit. Maskin contains a peptide sequence conserved among eIF-4E binding proteins that is involved in oocyte development. D-TACC cooperates with another conserved microtubule-associated protein Msps to stabilise spindle poles during cell division. The diversity of function already attributed to this protein family, including both transforming and tumour suppressor properties, should ensure that a new and interesting narrative is about to unfold.