Mean Curvature Flow from Conical Singularities

We prove Ilmanen's resolution of point singularities conjecture by establishing short-time smoothness of the level set flow of a smooth hypersurface with isolated conical singularities. This shows how the mean curvature flow evolves through asymptotically conical singularities and resolves a particular case of Ilmanen's strict genus reduction conjecture. Precisely, we prove that the level set flow of a smooth hypersurface $M^n\subset \mathbb{R}^{n+1}$, $2\leq n\leq 6$, with an isolated conical singularity is modeled on the level set flow of the cone. In particular, the flow fattens (instantaneously) if and only if the level set flow of the cone fattens.Comment: 22 pages, 3 figures. Comments welcome

The ErbB2ΔEx16 splice variant is a major oncogenic driver in breast cancer that promotes a pro-metastatic tumor microenvironment.

Amplification and overexpression of erbB2/neu proto-oncogene is observed in 20-30% human breast cancer and is inversely correlated with the survival of the patient. Despite this, somatic activating mutations within erbB2 in human breast cancers are rare. However, we have previously reported that a splice isoform of erbB2, containing an in-frame deletion of exon 16 (herein referred to as ErbB2ΔEx16), results in oncogenic activation of erbB2 because of constitutive dimerization of the ErbB2 receptor. Here, we demonstrate that the ErbB2ΔEx16 is a major oncogenic driver in breast cancer that constitutively signals from the cell surface. We further show that inducible expression of the ErbB2ΔEx16 variant in mammary gland of transgenic mice results in the rapid development of metastatic multifocal mammary tumors. Genetic and biochemical characterization of the ErbB2ΔEx16-derived mammary tumors exhibit several unique features that distinguish this model from the conventional ErbB2 ones expressing the erbB2 proto-oncogene in mammary epithelium. Unlike the wild-type ErbB2-derived tumors that express luminal keratins, ErbB2ΔEx16-derived tumors exhibit high degree of intratumoral heterogeneity co-expressing both basal and luminal keratins. Consistent with these distinct pathological features, the ErbB2ΔEx16 tumors exhibit distinct signaling and gene expression profiles that correlate with activation of number of key transcription factors implicated in breast cancer metastasis and cancer stem cell renewal

Genomic analysis of early murine mammary gland development using novel probe-level algorithms

We describe a novel algorithm (ChipStat) for detecting gene-expression changes utilizing probe-level comparisons of replicate Affymetrix oligonucleotide microarray data. A combined detection approach is shown to yield greater sensitivity than a number of widely used methodologies including SAM, dChip and logit-T. Using this approach, we identify alterations in functional pathways during murine neonatal-pubertal mammary development that include the coordinate upregulation of major urinary proteins and the downregulation of loci exhibiting reciprocal imprinting

Augmenting forearm crutches with wireless sensors for lower limb rehabilitation

Forearm crutches are frequently used in the rehabilitation of an injury to the lower limb. The recovery rate is improved if the patient correctly applies a certain fraction of their body weight (specified by a clinician) through the axis of the crutch, referred to as partial weight bearing (PWB). Incorrect weight bearing has been shown to result in an extended recovery period or even cause further damage to the limb. There is currently no minimally invasive tool for long-term monitoring of a patient's PWB in a home environment. This paper describes the research and development of an instrumented forearm crutch that has been developed to wirelessly and autonomously monitor a patient's weight bearing over the full period of their recovery, including its potential use in a home environment. A pair of standard forearm crutches are augmented with low-cost off-the-shelf wireless sensor nodes and electronic components to provide indicative measurements of the applied weight, crutch tilt and hand position on the grip. Data are wirelessly transmitted between crutches and to a remote computer (where they are processed and visualized in LabVIEW), and the patient receives biofeedback by means of an audible signal when they put too much or too little weight through the crutch. The initial results obtained highlight the capability of the instrumented crutch to support physiotherapists and patients in monitoring usage

Conditional activation of Neu in the mammary epithelium of transgenic mice results in reversible pulmonary metastasis

AbstractTo determine the impact of tumor progression on the reversibility of Neu-induced tumorigenesis, we have used the tetracycline regulatory system to conditionally express activated Neu in the mammary epithelium of transgenic mice. When induced with doxycycline, bitransgenic MMTV-rtTA/TetO-NeuNT mice develop multiple invasive mammary carcinomas, essentially all of which regress to a clinically undetectable state following transgene deinduction. This demonstrates that Neu-initiated tumorigenesis is reversible. Strikingly, extensive lung metastases arising from Neu-induced mammary tumors also rapidly and fully regress following the abrogation of Neu expression. However, despite the near universal dependence of both primary tumors and metastases on Neu transgene expression, most animals bearing fully regressed Neu-induced tumors ultimately develop recurrent tumors that have progressed to a Neu-independent state

Predicting the Next Eye Pathogen: Analysis of a Novel Adenovirus

For DNA viruses, genetic recombination, addition, and deletion represent important evolutionary mechanisms. Since these genetic alterations can lead to new, possibly severe pathogens, we applied a systems biology approach to study the pathogenicity of a novel human adenovirus with a naturally occurring deletion of the canonical penton base Arg-Gly-Asp (RGD) loop, thought to be critical to cellular entry by adenoviruses. Bioinformatic analysis revealed a new highly recombinant species D human adenovirus (HAdV-D60). A synthesis of in silico and laboratory approaches revealed a potential ocular tropism for the new virus. In vivo, inflammation induced by the virus was dramatically greater than that by adenovirus type 37, a major eye pathogen, possibly due to a novel alternate ligand, Tyr-Gly-Asp (YGD), on the penton base protein. The combination of bioinformatics and laboratory simulation may have important applications in the prediction of tissue tropism for newly discovered and emerging viruses

Isoform-specific requirement for Akt1 in the developmental regulation of cellular metabolism during lactation

SummaryThe metabolic demands and synthetic capacity of the lactating mammary gland exceed that of any other tissue, thereby providing a useful paradigm for understanding the developmental regulation of cellular metabolism. By evaluating mice bearing targeted deletions in Akt1 or Akt2, we demonstrate that Akt1 is specifically required for lactating mice to synthesize sufficient quantities of milk to support their offspring. Whereas cellular proliferation, differentiation, and apoptosis are unaffected, loss of Akt1 disrupts the coordinate regulation of metabolic pathways that normally occurs at the onset of lactation. This results in a failure to upregulate glucose uptake, Glut1 surface localization, lipid synthesis, and multiple lipogenic enzymes, as well as a failure to downregulate lipid catabolic enzymes. These findings demonstrate that Akt1 is required in an isoform-specific manner for orchestrating many of the developmental changes in cellular metabolism that occur at the onset of lactation and establish a role for Akt1 in glucose metabolism

Does Screening for Pain Correspond to High Quality Care for Veterans?

Routine numeric screening for pain is widely recommended, but its association with overall quality of pain care is unclear. To assess adherence to measures of pain management quality and identify associated patient and provider factors. A cross-sectional visit-based study. One hundred and forty adult VA outpatient primary care clinic patients reporting a numeric rating scale (NRS) of moderate to severe pain (four or more on a zero to ten scale). Seventy-seven providers completed a baseline survey regarding general pain management attitudes and a post-visit survey regarding management of 112 participating patients. We used chart review to determine adherence to four validated process quality indicators (QIs) including noting pain presence, pain character, and pain control, and intensifying pharmacological intervention. The average NRS was 6.7. Seventy-three percent of charts noted the presence of pain, 13.9% the character, 23.6% the degree of control, and 15.3% increased pain medication prescription. Charts were more likely to include documentation of pain presence if providers agreed that “patients want me to ask about pain” and “pain can have negative consequences on patient’s functioning”. Charts were more likely to document character of pain if providers agreed that “patients are able to rate their pain”. Patients with musculoskeletal pain were less likely to have chart documentation of character of pain. Despite routine pain screening in VA, providers seldom documented elements considered important to evaluation and treatment of pain. Improving pain care may require attention to all aspects of pain management, not just screening

Causal associations between depression symptoms and cognition in a community-based cohort of older adults.

OBJECTIVE: To evaluate the temporal association between depression symptoms and cognitive function in older adults over a 4-year period. METHODS: Using a longitudinal, cross-lagged, population-based design, we studied depression symptoms and cognitive domains (including processing speed, verbal fluency, face and word recognition, episodic memory, and simple and choice reaction time) in 896 community-dwelling adults aged 70-97 years. RESULTS: Cross-lagged structural equation models suggested that initial depression symptoms affected subsequent processing speed and simple and choice reaction time but that cognition did not predict depression symptoms over time. The associations between depression and cognitive variables were attenuated when the models were adjusted for sensory impairment, physical health, and locus of control. CONCLUSION: The findings suggest that, causally, depression precedes cognitive impairment in this age group and that the association is related to physical health and perceptions of a lack of control