Changing practice paradigms: Negotiating your future Satiani, Bhagwan B., MD, MBA; Motew, Stephen J., MD; Darling, R. Clem, MD ...
Journal of vascular surgery,
04/2012, Letnik:
55, Številka:
4
Journal Article
Recenzirano
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There are many recent and ongoing changes in the practice of medicine from a business standpoint as well as in overall practice management. Economic and lifestyle desires have pushed many physicians ...to a decision point of whether or not to join a large multispecialty group or to sell their practice and become an employee of a hospital system. There are advantages and disadvantages to both options; however, deciding on the most appropriate path for each individual can be a daunting task. At our recent breakfast session at the vascular annual meeting in Chicago, Illinois, in June 2011, we brought to light these topics to try and help enlighten physicians on which option may be right for them. There is no single answer/option that will fit every practice, but discussion for various practice management designs are outlined and critiqued. This article cannot fully discuss each view in the allotted space, but it is designed to encourage thought and discussion among the vascular surgical community as a whole.
Small cell lung cancer (SCLC) is an aggressive cancer, and most patients present with cancer already spread beyond the lung. The receptor tyrosine kinase (RTK) c-MET has been implicated in various ...solid tumors, including SCLC, and is involved in mediating tumorigenesis, cell motility, scattering, invasion and metastasis. Mutations of c-Met have been described in renal papillary carcinoma and gastrointestinal cancers including hepatocellular carcinoma. The sequence of c-MET was examined for possible mutations in the 10 SCLC cell lines and 32 paired-SCLC/normal tissues. Novel c-MET alterations were identified among 3 of 10 separate SCLC cell lines and in 4 of 32 SCLC tumor tissue samples. These include two different c-MET missense mutations in the juxtamembrane (JM) domain (R988C found in NCI-H69 and H249 cell lines; and T1010I in SCLC tumor sample T31). Also, there are one Sema domain missense mutation (E168D in SCLC tumor sample T5), two-base-pair insertional mutations (IVS13- (52-53)insCT in both SCLC tumor samples T26 and T27) within the pre-JM intron 13, as well as an alternative transcript involving exon 10 (H128 cell line). c-MET receptors are expressed at various levels among the 10 SCLC cell lines studied (high expression: H69, H345, H510, and H526; medium-expression: H128 and H146; and low/no-expression: H82, H209, H249, and H446). The level of c-MET expression does not have any apparent correlation with presence or absence of mutations of c-MET in the cell lines. We show that the two identified JM mutations (R988C and T1010I), when introduced into the interleukin-3 (IL-3)-dependent BaF3 cell line, regulated cell proliferation resulting in a small but significant growth factor independence. When introduced into a SCLC cell line (H446, with minimal endogenous wild-type c-MET expression), the JM mutations also regulated cell morphology and adhesion, as well as causing enhanced tumorigenicity by both increases in focus-formation and soft-agar colony-formation assays. Both of the JM mutations also increased cell motility and migration evident in wound healing assay and time-lapse video-microscopy speed analysis. The JM mutations also altered the c-MET RTK signaling, resulting in preferentially increased constitutive tyrosine phosphorylation of various cellular proteins, including the key focal adhesion protein paxillin on tyrosine residue Y31 (first CRKL-binding site), correlating with increased motility. These results suggest a novel and unique role of the JM domain in c-MET signaling in SCLC with significant implications in cytoskeletal functions and metastatic potential. The novel JM gain-of-function somatic mutations described are the first to be reported in SCLC, and may be associated with a more aggressive phenotype. It would now be useful to study the inhibition of c-MET as a therapeutic target against SCLC.
The solubilities of three estrogenic hormonesestrone, 17β-estradiol, and 17α-ethynylestradioland the industrial pollutant bisphenol A were measured in water, dilute acid and alkali (pH 4 and 10, ...respectively), and aqueous KNO3 (0.01 mol·L-1 and 0.1 mol·L-1). The concentrations of saturated solutions, after equilibration at (25.0 ± 0.5) °C with excess solid for 4 days, were determined by HPLC. Six replicate results were obtained for each solute−solvent pair: the coefficient of variation was in most cases < 5 %. The solubilities in pure water with standard deviations were estrone (1.30 ± 0.08) mg·L-1, 17β-estradiol (1.51 ± 0.04) mg·L-1, 17α-ethynylestradiol (9.20 ± 0.09) mg·L-1, and bisphenol A (300 ± 5) mg·L-1. The solubility of each of the hormones was unchanged between pH 4 and pH 7 but was greater at pH 10. At pH 7, the hormones became progressively less soluble as the ionic strength increased from 0.0 to 0.1 mol·L-1. By contrast the solubility of bisphenol A was essentially the same under all of the experimental conditions tested.
Different mutants of Cowpea Mosaic Virus (CPMV) have been used as scaffolds to bind 2 and 5 nm gold nanoparticles through gold−sulfur bond formation at specific locations on the virus to produce ...patterns of specific interparticle distances. TEM images confirm that the bound gold particles produce patterns of gold nanoparticles that correlate well with models built from the known locations of the inserted cysteine groups on the capsid. These results demonstrate that it is possible to use CPMV mutants as nanoscale scaffolds to place gold nanoparticles at fixed interparticle distances.
To determine the ability to induce tumor-specific immunity with individual mutant K-ras-or p53-derived peptides and to monitor clinical outcome.
Patients in varying stages of disease underwent ...genetic analysis for mutations in K-ras and p53. Thirty-nine patients were enrolled. Seventeen-mer peptides were custom synthesized to the corresponding mutation. Baseline immunity was assessed for cytotoxic T-lymphocyte (CTL) response and interferon gamma (IFN-gamma) release from mutant peptide-primed lymphocytes. Patients' peripheral-blood mononuclear cells were pulsed with the corresponding peptide, irradiated, and applied intravenously. Patients were observed for CTL, IFN-gamma, interleukin (IL) -2, IL-5, and granulocyte-macrophage colony-stimulating factor responses, for treatment-related toxicity, and for tumor response.
No toxicity was observed. Ten (26%) of 38 patients had detectable CTL against mutant p53 or K-ras, and two patients were positive for CTL at baseline. Positive IFN-gamma responses occurred in 16 patients (42%) after vaccination, whereas four patients had positive IFN-gamma reaction before vaccination. Of 29 patients with evident disease, five experienced a period of stable disease. Favorable prognostic markers were detectable CTL activity and a positive IFN-gamma reaction but not IL-5 release. Median survival times of 393 v 98 days for a positive versus negative CTL response (P = .04), respectively, and of 470 v 88 days for a positive versus negative IFN-gamma response (P = .02), respectively, were detected.
Custom-made peptide vaccination is feasible without any toxicity. CTL and cytokine responses specific to a given mutation can be induced or enhanced with peptide vaccines. Cellular immunity to mutant p53 and K-ras oncopeptides is associated with longer survival.
Scanning electron microscopy, surface area determination, elemental analysis, organic matter extraction and solid-state cross polarization/magic angle spinning and Bloch decay/magic angle spinning
...13C nuclear magnetic resonance (NMR) spectroscopy were used to investigate distinctive features among carbonaceous combustion residues. Black carbon (BC) samples included diesel soot, urban dust, carbon black, chimney soot, vegetation fire residues, wood and straw charcoals. Particles varied from small spheres (<50 nm) in fossil BC (>100 m
2/g), to large layered structures in plant-derived BC (generally <8 m
2/g). Chimney soot also included large (>1 μm) liquid-like structures, while spherules >100 nm were unique to urban dust. The ratios of amorphous to soot carbon (SC) (isolated by thermal degradation) were not necessarily correlated with the degree of aromaticity estimated from H/C ratios. In particular, values of SC in diesel soot were clearly overestimated. Solvent-extractable organic matter (SEOM) was <2% for charcoals and carbon black, but >13% for urban dust, chimney and diesel soot. SEOM is thought to clog pores or to form large waxy globules, hence reducing surface areas. The ratio of polar/nonpolar SEOM was generally <7 for fossil BC, but >30 for plant-derived BC. NMR analysis revealed essentially one chemical shift in the aromatic C region of charcoals, while diesel soot also showed important aliphatic contributions. Aliphatic and oxygenated C predominated over aryl C in urban dust and chimney soot. These morphological and chemical characteristics of the BC samples are discussed in terms of their environmental implications.
Small cell lung cancer (SCLC) is an aggressive cancer characterized by several autocrine growth mechanisms including stem cell factor and its receptor c-Kit. In order to arrive at potentially new and ...novel therapy for SCLC, we have investigated the effects of the tyrosine kinase inhibitor, STI 571, on SCLC cell lines. It has been previously reported that STI 571 does not only inhibit cellular Abl tyrosine kinase activity but also the PDGF receptor and c-Kit tyrosine kinases at similar concentrations (approximately 0.1 microM). There is no expression of the PDGF-receptor, and the Abl kinase is not activated by SCLC, but over 70% of SCLC contain the c-Kit receptor. Utilizing this preliminary data, we have determined that three (NCI-H69, NCI-H146 and NCI-H209) of five (including NCI-H82 and NCI-H249) SCLC cell lines had detectable c-Kit receptors and were inhibited in growth and viability at concentrations 1 - 5 microM of STI 571 after 48 h of treatment. The SCLC cell lines, NCI-H69, NCI-H146 and NCI-H209, showed a dose-response (tested between 0.1 - 10 microM) inhibition of tyrosine phosphorylation of c-Kit as well as in vitro kinase activity (at 5 microM) of c-Kit in response to STI 571. STI 571 inhibited cell motility, as assessed by time-lapsed video microscopy, within 6 h of STI 571 treatment (5 microM). STI 571 also decreased intracellular levels of reactive oxygen species (ROS) by at least 60%, at a concentration (5 microM) that also inhibited cell growth. Cell cycle analysis of STI 571 responsive cells showed that cells were generally slowed in G2/M phase, but there was no arrest at G1/S. A downstream phosphorylation target of c-Kit, Akt, was not phosphorylated in response to stem cell factor in the presence of STI 571. These data imply that STI 571 inhibits growth of SCLC cells through a mechanism that involves inactivation of the tyrosine kinase c-Kit. The effectiveness of STI 571 in this study suggests this drug may be useful in a clinical trial, for patients with SCLC. Oncogene (2000) 19, 3521 - 3528
The adsorption of citric acid onto goethite, kaolinite, and illite was measured as a function of pH (adsorption edges) and concentration (adsorption isotherms) at 25
°C. The greatest adsorption was ...onto goethite and the least onto illite. Adsorption onto goethite was at a maximum below pH 5 and decreased as the pH was increased to pH 9. For kaolinite, maximum adsorption occurred between pH 4.5 and pH 7, decreasing below and above this pH region, while for illite maximum adsorption occurred between about pH 5 and pH 7, decreasing at both lower and higher pH. ATR-FTIR spectra of citrate adsorbed to goethite at pH 4.6, pH 7.0, and pH 8.8 were compared with those of citrate solutions between pH 3.5 and pH 9.1. While the spectra of adsorbed citrate resembled those of the fully deprotonated solution species, there were significant differences. In particular the CO symmetric stretching band of the adsorbed species at pH 4.6 and 7.0 changed shape and was shifted to higher wave number. Further spectral analysis suggested that citrate adsorbed as an inner-sphere complex at pH 4.6 and pH 7.0 with coordination to the surface most probably via one or more carboxyl groups. At pH 8.8 the intensity of the adsorbed bands was much smaller but their shape was similar to those from the deprotonated citrate solution species, suggesting outer-sphere adsorption. Insufficient citric acid adsorbed onto illite or kaolinite to provide spectroscopic information about the mode of adsorption onto these minerals. Data from adsorption experiments, and from potentiometric titrations of suspensions of the minerals in the presence of citric acid, were fitted by extended constant-capacitance surface complexation models. On the goethite surface a monodentate inner-sphere complex dominated adsorption below pH 7.9, with a bidentate outer-sphere complex required at higher pH values. On kaolinite, citric acid adsorption was modeled with a bidentate outer-sphere complex at low pH and a monodentate outer-sphere complex at higher pH. There is evidence of dissolution of kaolinite in the presence of citric acid. For illite two bidentate outer-sphere complexes provided a good fit to all data.
The coronavirus disease 2019 (COVID-19) pandemic created an extremely disruptive challenge for health care leaders that required a rapid, dynamic, and innovative response. The purpose of this ...manuscript is to share the leadership actions and decisions at Mayo Clinic in Florida during the first 6 months of the pandemic (February to July 2020). We note 4 strategies that contributed to an effective response: (1) leverage experience with disaster preparedness and mobilize regional and national networks; (2) use surge models to anticipate and to address supply chain issues as well as practical and financial effects of the pandemic; (3) adapt creatively to establish new safety and procedural protocols in various areas for various populations; and (4) communicate timely information effectively and be the common source of truth. Mayo Clinic in Florida was able to address the surges of patients with COVID-19, to provide ongoing tertiary care, and to restore function within the first 6 months with new, strengthened practices and protocols.
Sorption of the endocrine disrupting chemicals (EDCs) bisphenol A (BPA), 17
α-ethynylestradiol (EE2) and estrone (E1) from 3 μM aqueous solutions in 10 mM KNO
3 to goethite, kaolinite and ...montmorillonite was investigated at 25 °C. Uptake of the EDCs by goethite and kaolinite suspensions was <20%, and little affected by pH. Sorption by montmorillonite was greater, ranging from 20 to 60%, and steadily increased from about pH 7. The amount of EDC sorbed to the mineral phases generally increased in the order of decreasing solubility (BPA
<
EE2
<
E1). Sorption to goethite and kaolinite was rapid (<10 min), but much slower for montmorillonite, to which sorption continued for 24–48 h. Although the EDCs desorbed rapidly and completely from goethite and kaolinite, only small amounts desorbed from montmorillonite below pH 7, and no recovery was observed at pH 10. The kinetic and desorption experiments indicate that the EDCs intercalate into the interlayer spaces of montmorillonite, but for goethite and kaolinite sorption probably occurs at external surfaces.
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