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This study sought to quantify in vitro antiproliferative effects of pamidronate in feline cancer cells and assess feasibility of use of pamidronate in cats by assessing short-term toxicity and dosing schedule in cats with bone-invasive cancer. A retrospective pilot study included eight cats with bone invasive cancer treated with intravenous pamidronate. In vitro, pamidronate reduced proliferation in feline cancer cells (P < 0.05). One cat treated with pamidronate in combination with chemotherapy and two cats treated with pamidronate as a single agent after failing prior therapy had subjective clinically stable disease; median progression free interval in these cats from initial pamidronate treatment was 81 days. Three cats developed azotemia while undergoing various treatment modalities including nonsteroidal anti-inflammatory drugs and pamidronate. Median overall survival was 116.5 days for all cats and 170 days for cats with oral squamous cell carcinoma. Median progression free survival was 55 days for all cats and 71 days for cats with oral squamous cell carcinoma. Pamidronate therapy appears feasible for administration in cancer bearing cats with aggressive bone lesions in the dose range of 1-2 mg/kg every 21-28 days for multiple treatments. No acute or short-term toxicity was directly attributable to pamidronate.

Understanding molecular recognition is of fundamental importance in applications such as therapeutics, chemical catalysis and sensor design. The most common recognition motifs involve biological macromolecules such as antibodies and aptamers. The key to biorecognition consists of a unique three-dimensional structure formed by a folded and constrained bioheteropolymer that creates a binding pocket, or an interface, able to recognize a specific molecule. Here, we show that synthetic heteropolymers, once constrained onto a single-walled carbon nanotube by chemical adsorption, also form a new corona phase that exhibits highly selective recognition for specific molecules. To prove the generality of this phenomenon, we report three examples of heteropolymer-nanotube recognition complexes for riboflavin, L-thyroxine and oestradiol. In each case, the recognition was predicted using a two-dimensional thermodynamic model of surface interactions in which the dissociation constants can be tuned by perturbing the chemical structure of the heteropolymer. Moreover, these complexes can be used as new types of spatiotemporal sensors based on modulation of the carbon nanotube photoemission in the near-infrared, as we show by tracking riboflavin diffusion in murine macrophages.

Rationally designed siRNA delivery materials that are enabled by lipid-modified aminoglycosides are demonstrated. Leading materials identified are able to self-assemble with siRNA into well-defined nanoparticles and induce efficient gene knockdown both in vitro and in vivo. Histology studies and liver function tests reveal that no apparent toxicity is caused by these nanoparticles at doses over two orders of magnitude., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new class of nanogel demonstrates modular biodistribution and affinity for bone. Nanogels, ∼70 nm in diameter and synthesized via an astoichiometric click-chemistry in-emulsion method, controllably display residual, free clickable functional groups. Functionalization with a bisphosphonate ligand results in significant binding to bone on the inner walls of marrow cavities, liver avoidance, and anti-osteoporotic effects., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Intracellular delivery of macromolecules is a challenge in research and therapeutic applications. Existing vector-based and physical methods have limitations, including their reliance on exogenous materials or electrical fields, which can lead to toxicity or off-target effects. We describe a microfluidic approach to delivery in which cells are mechanically deformed as they pass through a constriction 30-80% smaller than the cell diameter. The resulting controlled application of compression and shear forces results in the formation of transient holes that enable the diffusion of material from the surrounding buffer into the cytosol. The method has demonstrated the ability to deliver a range of material, such as carbon nanotubes, proteins, and siRNA, to 11 cell types, including embryonic stem cells and immune cells. When used for the delivery of transcription factors, the microfluidic devices produced a 10-fold improvement in colony formation relative to electroporation and cell-penetrating peptides. Indeed, its ability to deliver structurally diverse materials and its applicability to difficult-to-transfect primary cells indicate that this method could potentially enable many research and clinical applications.

Carbon nanotube uptake was measured via high-speed confocal Raman imaging in live cells. Spatial and temporal tracking of two cell-intrinsic and nine nanotube-derived Raman bands was conducted simultaneously in RAW 264.7 macrophages. Movies resolved single (n, m) species, defects, and aggregation states of nanotubes transiently as well as the cell position, denoted by lipid and protein signals. This work portends the real-time molecular imaging of live cells and tissues using Raman spectroscopy, affording multiplexing and complete photostability.

The emergence of optofluidics has brought a high degree of tuneability and reconfigurability to optical devices. These possibilities are provided by characteristics of fluids including mobility, wide range of index modulation, and abrupt interfaces that can be easily reshaped. In this work, we created a new class of optofluidic waveguides, in which suspended mesoparticles were employed to greatly enhance the flexibility of the system. We demonstrated tuneable quasi single mode waveguides using spatially controllable mesoparticles in optofluidics. The coupling of waveguiding modes into the assembly of mesoparticles produces strong interactions and resonant conditions, which promote the transitions of the waveguiding modes. The modal response of the system depends on the distribution of packed particles above the polymeric rib waveguide which can be readily controlled under the appropriate combination of dielectrophoresis and hydrodynamic forces., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Because covalent chemistry can diminish the optical and electronic properties of single-walled carbon nanotubes (SWCNTs), there is significant interest in developing methods of controllably functionalizing the nanotube sidewall. To date, most attempts at obtaining such control have focused on reaction stoichiometry or strength of oxidative treatment. Here, we examine the role of surfactants in the chemical modification of single-walled carbon nanotubes with aryl diazonium salts. The adsorbed surfactant layer is shown to affect the diazonium derivatization of carbon nanotubes in several ways, including electrostatic attraction or repulsion, steric exclusion, and direct chemical modification of the diazonium reactant. Electrostatic effects are most pronounced in the cases of anionic sodium dodecyl sulfate and cationic cetyltrimethylammonium bromide, where differences in surfactant charge can significantly affect the ability of the diazonium ion to access the SWCNT surface. For bile salt surfactants, with the exception of sodium cholate, we find that the surfactant wraps tightly enough such that exclusion effects are dominant. Here, sodium taurocholate exhibits almost no reactivity under the explored reaction conditions, while for sodium deoxycholate and sodium taurodeoxycholate, we show that the greatest extent of reaction is observed among a small population of nanotube species, with diameters between 0.88 and 0.92 nm. The anomalous reaction of nanotubes in this diameter range seems to imply that the surfactant is less effective at coating these species, resulting in a reduced surface coverage on the nanotube. Contrary to the other bile salts studied, sodium cholate enables high selectivity toward metallic species and small band gap semiconductors, which is attributed to surfactant-diazonium coupling to form highly reactive diazoesters. Further, it is found that the rigidity of anionic surfactants can significantly influence the ability of the surfactant layer to stabilize the diazonium ion near the nanotube surface. Such Coulombic and surfactant packing effects offer promise toward employing surfactants to controllably functionalize carbon nanotubes., (© 2011 American Chemical Society)

Metastasis accounts for the vast majority of cancer deaths. The unique challenges for treating metastases include their small size, high multiplicity and dispersion to diverse organ environments. Nanoparticles have many potential benefits for diagnosing and treating metastatic cancer, including the ability to transport complex molecular cargoes to the major sites of metastasis, such as the lungs, liver and lymph nodes, as well as targeting to specific cell populations within these organs. This Review highlights the research, opportunities and challenges for integrating engineering sciences with cancer biology and medicine to develop nanotechnology-based tools for treating metastatic disease.

Many properties of single-walled carbon nanotubes (SWCNTs) make them ideal candidates for sensors, particularly for biological systems. Both their fluorescence in the near-infrared range of 820-1600 nm, where absorption by biological tissues is often minimal, and their inherent photostability are desirable attributes for the design of in vitro and in vivo sensors. The mechanisms by which a target molecule can selectively alter the fluorescent emission include primarily changes in emission wavelength (i.e., solvatochromism) and intensity, including effects such as charge-transfer transition bleaching and exciton quenching. The central challenge lies in engineering the nanotube interface to be selective for the analyte of interest. In this work, we review the recent development in this area over the past few years, and describe the design rules that we have developed for detecting various analytes, ranging from stable small molecules and reactive oxygen species (ROS) or reactive nitrogen species (RNS) to macromolecules. Applications to in vivo sensor measurements using these sensors are also described. In addition, the emerging field of SWCNT-based single-molecule detection using band gap fluorescence and the recent efforts to accurately quantify and utilize this unique class of stochastic sensors are also described in this article., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A class of peptides from the bombolitin family, not previously identified for nitroaromatic recognition, allows near-infrared fluorescent single-walled carbon nanotubes to transduce specific changes in their conformation. In response to the binding of specific nitroaromatic species, such peptide-nanotube complexes form a virtual "chaperone sensor," which reports modulation of the peptide secondary structure via changes in single-walled carbon nanotubes, near-infrared photoluminescence. A split-channel microscope constructed to image quantized spectral wavelength shifts in real time, in response to nitroaromatic adsorption, results in the first single-nanotube imaging of solvatochromic events. The described indirect detection mechanism, as well as an additional exciton quenching-based optical nitroaromatic detection method, illustrate that functionalization of the carbon nanotube surface can result in completely unique sites for recognition, resolvable at the single-molecule level.

We report the selective detection of single nitric oxide (NO) molecules using a specific DNA sequence of d(AT)(15) oligonucleotides, adsorbed to an array of near-infrared fluorescent semiconducting single-walled carbon nanotubes (AT(15)-SWNT). While SWNT suspended with eight other variant DNA sequences show fluorescence quenching or enhancement from analytes such as dopamine, NADH, L-ascorbic acid, and riboflavin, d(AT)(15) imparts SWNT with a distinct selectivity toward NO. In contrast, the electrostatically neutral polyvinyl alcohol enables no response to nitric oxide, but exhibits fluorescent enhancement to other molecules in the tested library. For AT(15)-SWNT, a stepwise fluorescence decrease is observed when the nanotubes are exposed to NO, reporting the dynamics of single-molecule NO adsorption via SWNT exciton quenching. We describe these quenching traces using a birth-and-death Markov model, and the maximum likelihood estimator of adsorption and desorption rates of NO is derived. Applying the method to simulated traces indicates that the resulting error in the estimated rate constants is less than 5% under our experimental conditions, allowing for calibration using a series of NO concentrations. As expected, the adsorption rate is found to be linearly proportional to NO concentration, and the intrinsic single-site NO adsorption rate constant is 0.001 s(-1) μM NO(-1). The ability to detect nitric oxide quantitatively at the single-molecule level may find applications in new cellular assays for the study of nitric oxide carcinogenesis and chemical signaling, as well as medical diagnostics for inflammation.

Naturally occurring photosynthetic systems use elaborate pathways of self-repair to limit the impact of photo-damage. Here, we demonstrate a complex consisting of two recombinant proteins, phospholipids and a carbon nanotube that mimics this process. The components self-assemble into a configuration in which an array of lipid bilayers aggregate on the surface of the carbon nanotube, creating a platform for the attachment of light-converting proteins. The system can disassemble upon the addition of a surfactant and reassemble upon its removal over an indefinite number of cycles. The assembly is thermodynamically metastable and can only transition reversibly if the rate of surfactant removal exceeds a threshold value. Only in the assembled state do the complexes exhibit photoelectrochemical activity. We demonstrate a regeneration cycle that uses surfactant to switch between assembled and disassembled states, resulting in an increased photoconversion efficiency of more than 300% over 168 hours and an indefinite extension of the system lifetime.

There has been renewed interest in solar concentrators and optical antennas for improvements in photovoltaic energy harvesting and new optoelectronic devices. In this work, we dielectrophoretically assemble single-walled carbon nanotubes (SWNTs) of homogeneous composition into aligned filaments that can exchange excitation energy, concentrating it to the centre of core-shell structures with radial gradients in the optical bandgap. We find an unusually sharp, reversible decay in photoemission that occurs as such filaments are cycled from ambient temperature to only 357 K, attributed to the strongly temperature-dependent second-order Auger process. Core-shell structures consisting of annular shells of mostly (6,5) SWNTs (E(g)=1.21 eV) and cores with bandgaps smaller than those of the shell (E(g)=1.17 eV (7,5)-0.98 eV (8,7)) demonstrate the concentration concept: broadband absorption in the ultraviolet-near-infrared wavelength regime provides quasi-singular photoemission at the (8,7) SWNTs. This approach demonstrates the potential of specifically designed collections of nanotubes to manipulate and concentrate excitons in unique ways.

An emerging concept in cell signalling is the natural role of reactive oxygen species such as hydrogen peroxide (H2O2) as beneficial messengers in redox signalling pathways. The nature of H2O2 signalling is confounded, however, by difficulties in tracking it in living systems, both spatially and temporally, at low concentrations. Here, we develop an array of fluorescent single-walled carbon nanotubes that can selectively record, in real time, the discrete, stochastic quenching events that occur as H2O2 molecules are emitted from individual human epidermal carcinoma cells stimulated by epidermal growth factor. We show mathematically that such arrays can distinguish between molecules originating locally on the cell membrane from other contributions. We find that epidermal growth factor induces 2 nmol H2O2 locally over a period of 50 min. This platform promises a new approach to understanding the signalling of reactive oxygen species at the cellular level.

A major challenge in the synthesis of nanotube or nanowire sensors is to impart selective analyte binding through means other than covalent linkages, which compromise electronic and optical properties. We synthesized a 3,4-diaminophenyl-functionalized dextran (DAP-dex) wrapping for single-walled carbon nanotubes (SWNTs) that imparts rapid and selective fluorescence detection of nitric oxide (NO), a messenger for biological signalling. The near-infrared (nIR) fluorescence of SWNT(DAP-dex) is immediately and directly bleached by NO, but not by other reactive nitrogen and oxygen species. This bleaching is reversible and shown to be caused by electron transfer from the top of the valence band of the SWNT to the lowest unoccupied molecular orbital of NO. The resulting optical sensor is capable of real-time and spatially resolved detection of NO produced by stimulating NO synthase in macrophage cells. We also demonstrate the potential of the optical sensor for in vivo detection of NO in a mouse model.

Objective: To examine the impact of changes in comorbidity--as measured by the Charlson comorbidity index--on self-rated health in a large sample of community-dwelling elderly over a 1-year period, and to examine the differential effects of changes in specific Charlson diagnostic categories., Study Design and Setting: Longitudinal survey data on self-rated health were linked with Medicare inpatient, outpatient, and physician visit data for 30,535 U.S. elderly residing in Pennsylvania. Multivariate logistic regression with fractional polynomials was used to model relationships involving baseline and changing Charlson comorbidity with self-rated health decline, and to evaluate covariate interactions., Results: Comorbidity change was associated with greater likelihood of worsened self-rated health, but the relationship was nonlinear and was moderated by age and baseline comorbidity. The impact of comorbidity change appeared to be less among older individuals and those with higher baseline comorbidity. Declines in self-rated health were most likely following new diagnoses for metastatic tumors, paralysis, and dementia., Conclusion: Self-rated health is responsive to changes in Charlson comorbidity, but nonlinearity and interactions suggest complexity in how elderly respond to comorbidity change. Younger individuals and those with initially low comorbidity are more likely to reduce self-ratings of health following new diagnoses for chronic conditions.

The cellular uptake and expulsion rates of length-fractionated single-walled carbon nanotubes (SWNT) from 130 to 660 nm in NIH-3T3 cells were measured via single particle tracking of their intrinsic photoluminescence. We develop a quantitative model to correlate endocytosis rate with nanoparticle geometry that accurately describes this data set and also literature results for Au nanoparticles. The model asserts that nanoparticles cluster on the cell membrane to form a size sufficient to generate a large enough enthalpic contribution via receptor ligand interactions to overcome the elastic energy and entropic barriers associated with vesicle formation. Interestingly, the endocytosis rate constant of SWNT (10(-3) min(-1)) is found to be nearly 1000 times that of Au nanoparticles (10(-6) min(-1)) but the recycling (exocytosis) rate constants are similar in magnitude (10(-4) to 10(-3) min(-1)) for poly(d,l-lactide-co-glycolide), SWNT, and Au nanoparticles across distinct cell lines. The total uptake of both SWNT and Au nanoparticles is maximal at a common radius of 25 nm when scaled using an effective capture dimension for membrane diffusion. The ability to understand and predict the cellular uptake of nanoparticles quantitatively should find utility in designing nanosystems with controlled toxicity, efficacy, and functionality.

The 1D quantum confinement of photogenerated excitons in single-walled carbon nanotubes (SWNT) can amplify the detection of molecular adsorption to where single-molecule discrimination is realizable, even from within living cells and tissues. Toward this aim, we present a type 1 collagen film, similar to those used as 3D cell scaffolds for tissue engineering, containing embedded SWNT capable of reporting single-molecule adsorption of quenching molecules. We utilize hidden Markov modeling to link single-molecule adsorption events to rate constants for H2O2, H+, and Fe(CN)6(3-). Among the three kinds of reactant molecules studied, H2O2 has the highest quenching equilibrium constant of 1.59 at 20 microM, whereas H+ is so insensitive that a similar equilibrium constant is achieved only with a concentration of 0.1 M (pH 1). The results were self-consistent because reverse (unquenching) rate constants (600 micros(-1) for H2O2, 1130 micros(-1) for H+ and 4000 micros(-1) for Fe(CN)6(3-)) were observed to be concentration-independent and the forward (quenching) rate constants varied monotonically with concentration. The quenching rate constants also increased with an increase in the redox potential of the quencher, indicating that electron transfer increases the adsorption equilibrium constant on the nanotube surface and, hence, the dwell time of the quencher. These developments provide the material, analytical, and mechanistic groundwork for SWNT to function as single-molecule stochastic biosensors.

Over 10000 individual trajectories of nonphotobleaching single-walled carbon nanotubes (SWNT) were tracked as they are incorporated into and expelled from NIH-3T3 cells in real time on a perfusion microscope stage. An analysis of mean square displacement allows the complete construction of the mechanistic steps involved from single duration experiments. We observe the first conclusive evidence of SWNT exocytosis and show that the rate closely matches the endocytosis rate with negligible temporal offset. We identify and study the endocytosis and exocytosis pathway that leads to the previously observed aggregation and accumulation of SWNT within the cells.

Recently, Heller et al. reported length-dependent effects on the relative photoluminescence (PL) quantum yield of single walled carbon nanotubes (SWNTs) [Heller et al J. Am. Chem. Soc. 2004, 126, 14567-14573]. We propose a simple model involving thermal diffusion of excitons along the nanotube axis and quenching at the ends, to explain the observed trend in their data. By fitting to our model, we extract a diffusion coefficient of 6 cm(2)/s for excitons in SWNTs. Assuming a mono exponential decay of exciton PL, we also predict that effective length-dependent PL lifetimes for these excitons lie in the range of 1-27 ps. Experimental observations are shown to be consistent with stochastic rather than wavepacket-like exciton migration, which is in agreement with ultrafast excitonic dephasing. Edge effects seem to limit the use of short SWNTs in imaging and optical sensing applications.

Background: Cyclooxygenase-2 (COX-2) and its principle enzymatic metabolite, prostaglandin E2 (PGE2), are implicated in cancer progression. Based upon immunohistochemical (IHC) evidence that several tumor types in animals overexpress COX-2 protein, COX-2 inhibitors are used as anticancer agents in dogs and cats., Hypothesis: IHC is inaccurate for assessing tumor-associated COX-2 protein and enzymatic activity., Methods: Five mammalian cell lines were assessed for COX-2 protein expression by IHC and Western blot analysis (WB), and functional COX-2 activity was based upon PGE2 production., Results: Detection of COX-2 protein by IHC and WB were in agreement in 4 of 5 cell lines. In 1 cell line that lacked COX-2 gene transcription because of promoter hypermethylation (HCT-116), IHC produced false-positive staining for COX-2 protein expression. Functional COX-2 enzymatic activity was dissociated from relative IHC-based COX-2 protein expression in 2 cell lines (RPMI 2650 and SCCF1). The RPMI 2650 cell line demonstrated strong COX-2 protein expression but minimal PGE2 production., Conclusions and Clinical Importance: Western blot is more accurate than IHC for the detection of COX-2 protein in the cell lines studied. Furthermore, the semiquantitative identification of COX-2 protein by IHC or WB does not necessarily correlate with enzymatic activity. Based upon the potential inaccuracy of IHC and dissociation of COX-2 protein expression from enzymatic activity, the practice of instituting treatment of tumors with COX-2 inhibitors based solely on IHC results should be reconsidered.

Magnetic iron oxide nanoparticles and near-infrared (NIR) fluorescent single-walled carbon nanotubes (SWNT) form heterostructured complexes that can be utilized as multimodal bioimaging agents. Fe catalyst-grown SWNT were individually dispersed in aqueous solution via encapsulation by oligonucleotides with the sequence d(GT)15, and enriched using a 0.5 T magnetic array. The resulting nanotube complexes show distinct NIR fluorescence, Raman scattering, and visible/NIR absorbance features, corresponding to the various nanotube species. AFM and cryo-TEM images show DNA-encapsulated complexes composed of a approximately 3 nm particle attached to a carbon nanotube on one end. X-ray diffraction (XRD) and superconducting quantum interference device (SQUID) measurements reveal that the nanoparticles are primarily Fe2O3 and superparamagnetic. The Fe2O3 particle-enriched nanotube solution has a magnetic particle content of approximately 35 wt %, a magnetization saturation of approximately 56 emu/g, and a magnetic relaxation time scale ratio (T1/T2) of approximately 12. These complexes have a longer spin-spin relaxation time (T2 approximately 164 ms) than typical ferromagnetic particles due to the smaller size of their magnetic component while still retaining SWNT optical signatures. Macrophage cells that engulf the DNA-wrapped complexes were imaged using magnetic resonance imaging (MRI) and NIR mapping, demonstrating that these multifunctional nanostructures could potentially be useful in multimodal biomedical imaging.

Objective: To determine the extent to which changes in medication use and health influence the decision to quit drinking among older adults., Method: The sample consisted of 8,883 elderly enrolled in Pennsylvania's Pharmaceutical Assistance Contract for the Elderly (PA-PACE) program who completed surveys in 2000 and 2002. Survey data were linked with prescription claims to examine medication and health factors associated with drinking cessation between baseline and follow-up., Results: Overall, 3.9% of those using alcohol at baseline quit drinking during the study period. Logistic regression results showed that individuals who initiated antipsychotic (OR = 2.92) and antineoplastic therapies (OR = 2.67) were the most likely to quit drinking., Discussion: These findings support the hypothesis that elderly quit drinking in response to ill health. Results have implications for alcohol interventions in older adults and underscore the importance of separating former drinkers from lifetime abstainers in the study of alcohol-health relationships.

The transition of DNA secondary structure from an analogous B to Z conformation modulates the dielectric environment of the single-walled carbon nanotube (SWNT) around which it is adsorbed. The SWNT band-gap fluorescence undergoes a red shift when an encapsulating 30-nucleotide oligomer is exposed to counter ions that screen the charged backbone. The transition is thermodynamically identical for DNA on and off the nanotube, except that the propagation length of the former is shorter by five-sixths. The magnitude of the energy shift is described by using an effective medium model and the DNA geometry on the nanotube sidewall. We demonstrate the detection of the B-Z change in whole blood, tissue, and from within living mammalian cells.

Cyclooxygenase-2 (COX-2) is an inducible member of the family of cyclooxygenase enzymes that has been implicated in the genesis of numerous cancers. The role of COX-2 in canine mammary neoplasia remains to be more clearly elucidated. The goal of the study reported here was to determine whether a direct association between levels of COX-2 expression and tumor histologic subtype exists in canine mammary carcinoma. Immunohistochemical analysis was performed using a polyclonal antiprostaglandin G/H synthase 2 IgG COX-2 antibody. Sections from the kidneys of young dogs, which stain positive for COX-2 in the macula densa, served as positive controls. Slides were reviewed by a single pathologist, and were evaluated for COX-2 expression according to previously established scales. Positive-staining tumors were given a COX-2 staining distribution (on the basis of the percentage of positive staining cells in five 400x fields) and intensity score according to previously established scales. The product of the COX-2 staining distribution and intensity scores was calculated to create a COX-2 staining index. COX-2 expression was detected in 28 of 50 (56%) samples evaluated. Anaplastic carcinomas had a significantly higher COX-2 staining distribution, intensity, and index, compared with those for adenocarcinomas (P < 0.0001). The overall percentage of positive tumors (56%) was consistent with that of prior studies. To the authors' knowledge, these results indicate, for the first time, a direct association between COX-2 expression and tumor histologic subtype in canine mammary carcinomas. Future research directed at measuring tumor response in canine mammary carcinoma patients treated with a selective COX-2 inhibitor is indicated.

Objectives: To examine the patterns and prevalence of concomitant alcohol and alcohol-interactive (AI) drug use in older people., Design: Cross-sectional analysis of survey and prescription claims data., Setting: The Pennsylvania Pharmaceutical Assistance Contract for the Elderly (PA-PACE) program, a state-funded program providing prescription benefits to older people with low to moderate incomes., Participants: A total of 83,321 PA-PACE cardholders (age range 65-106) who were using any prescription medications at the time of survey completion., Measurements: All AI drugs were identified using a database of medication warning labels obtained from First DataBank. Prescription drug claims were used to characterize AI drug exposure according to therapeutic class of prescription drug use. A mail survey of PA-PACE cardholders was used to examine alcohol use, as well as sociodemographic and health factors associated with concomitant use of alcohol and AI drugs., Results: Seventy-seven percent of all prescription drug users were exposed to AI medications, with significant variation in exposure and concomitant alcohol use according to therapeutic class. Overall, 19% of AI drug users reported concomitant alcohol use, compared with 26% of non-AI drug users (P<.001). Multinomial logistic regression analyses showed that certain groups of older people, including younger older people, men, and those with higher educational levels, were at greater risk for concomitant exposure to alcohol and AI drugs., Conclusion: Many older people use alcohol in combination with AI prescription drugs. Clinicians should warn every patient who is prescribed an AI drug about alcohol-drug interactions, especially those at high risk for concomitant exposure.

Background: Many women have discontinued hormone replacement therapy (HRT) in view of recent findings. The goal of this study was to determine if HRT discontinuation is associated with changes in health-related quality of life (HRQOL) in elderly women., Methods: We studied women enrolled in Pennsylvania's Pharmaceutical Assistance Contract for the Elderly (PACE) program, linking prescription claims with data from a longitudinal mail survey. HRQOL measures included the number of days out of the last 30 that physical health was not good and analogous measures for mental health, pain, and interference with activities, as well as a composite "healthy days" measure developed by CDC. Longitudinal analyses focused on 2,357 women who completed surveys in both 2002 and 2003, and who used HRT at baseline (mean age = 75.5, range = 65-102). Propensity scores were used to match HRT continuers and discontinuers according to HRT type, demographics, and baseline HRQOL. Analysis of covariance was used to compare HRQOL change in continuers and discontinuers., Results: Between 2002 and 2003, 43% of HRT users discontinued therapy. Analysis of covariance to examine HRQOL change revealed complex interactions with age. Discontinuers aged 65-74 reported greater increases in days in which mental health was not good (p < .05), fewer "healthy days" (p < .05), more days in which health interfered with activities (p < .01), and more days with pain (p < .01). Among women aged 75-84, HRT discontinuers reported more days in which physical health was not good (p < .01); no other significant effects were observed in this group. Relative to HRT continuers, discontinuers aged 85 and older experienced apparent HRQOL improvements following cessation, with fewer days in which physical health was not good (p < .01), fewer days of poor mental health (p < .05), and more "healthy days" (p < .01)., Conclusions: These results suggest that there are substantial age differences in response to HRT discontinuation. While women aged 65-74 experienced apparent declines in HRQOL following HRT cessation, women aged 85 and older experienced relative improvements. The HRQOL declines observed among younger women underscore the importance of communication between clinicians and patients throughout the discontinuation process. These results also demonstrate the value of HRQOL surveillance as a component of health program administration.

To determine whether cyclooxygenase-2 (COX-2) is expressed in canine hemangiosarcoma (HSA), histiocytic sarcoma (HS), and grade-II mast cell tumor (MCT), we performed immunohistochemistry using COX-2 antibodies in the aforementioned tumors. Twenty cases of each tumor type were selected initially from the Laboratory of Pathology archives of cases submitted through the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. Immunohistochemistry was performed, using a polyclonal antiprostaglandin endoperoxide synthase immunoglobulin G COX-2 antibody. Sections from the kidneys of young dogs, in which the macula densa stains positive for COX-2, served as positive controls. Slides were reviewed by a single pathologist (M. H. Goldschmidt) and graded for COX-2 expression according to previously established scales. Descriptive data is given for each tumor type. COX-2 expression was identified in 0 of 19 HSA, 1 of 20 HS, and 1 of 17 grade-II MCT. Although COX-2 has been shown to be overexpressed in selected human sarcomas and hematopoeitic tumors, these results indicate that canine HSA, HS, and MCT do not express COX-2 in any appreciable fashion.

We present an approach called pulsed multiline excitation (PME) for measurements of multicomponent, fluorescence species and demonstrate its application in capillary electrophoresis for DNA sequencing. To fully demonstrate the advantages of PME, a fluorescent dye set has been developed whose absorption maxima span virtually the entire visible spectrum. Unlike emission wavelength-dependent approaches for identifying fluorescent species, the removal of the spectral component in PME confers a number of advantages including higher and normalized signals from all dyes present in the assay, the elimination of spectral cross-talk between dyes, and higher signal collection efficiency. Base-calling is unambiguously determined once dye mobility corrections are made. These advantages translate into significantly enhanced signal quality as illustrated in the primary DNA sequencing data and provide a means for achieving accurate base-calling at lower reagent concentrations.

Patterned networks of hippocampal neurons were generated on peptide-coated gold substrates prepared by microscope projection photolithography and microcontact printing. A 19 amino acid peptide fragment of laminin A (PA22-2) that includes the IKVAV cell adhesion domain was used to direct patterns of cell adhesion in primary culture. Microscale grid patterns of peptide were deposited on gold-coated glass cover slips by soft lithography using "stamps" fashioned from polydimethylsiloxane. Strong coordination bonding between gold atoms on the surface and the sulfur atoms of the N-terminal cysteine residues supported stable adhesion of the peptide, which was confirmed by immunofluorescence using anti-IKVAV antiserum. Dispersed hippocampal cells isolated from neonatal mouse pups were grown on peptide-patterned gold substrates for 7 days. Neurons preferentially adhered to peptide-coated regions of the gold surface and restricted their processes to the peptide patterns. Whole cell recordings of neurons grown in patterned arrays revealed an average membrane potential of -50 mV, as well as the presence of voltage-gated ion conductances. Peptide-modified gold surfaces serve as convenient and effective substrates for growing ordered neural networks that are compatible with existing multi-electrode array recording technology.

Molecular detection using near-infrared light between 0.9 and 1.3 eV has important biomedical applications because of greater tissue penetration and reduced auto-fluorescent background in thick tissue or whole-blood media. Carbon nanotubes have a tunable near-infrared emission that responds to changes in the local dielectric function but remains stable to permanent photobleaching. In this work, we report the synthesis and successful testing of solution-phase, near-infrared sensors, with beta-D-glucose sensing as a model system, using single-walled carbon nanotubes that modulate their emission in response to the adsorption of specific biomolecules. New types of non-covalent functionalization using electron-withdrawing molecules are shown to provide sites for transferring electrons in and out of the nanotube. We also show two distinct mechanisms of signal transduction-fluorescence quenching and charge transfer. The results demonstrate new opportunities for nanoparticle optical sensors that operate in strongly absorbing media of relevance to medicine or biology.

Gel electrophoresis and column chromatography conducted on individually dispersed, ultrasonicated single-walled carbon nanotubes yield simultaneous separation by tube length and diameter. Electroelution after electrophoresis is shown to produce highly resolved fractions of nanotubes with average lengths between 92 and 435 nm. Separation by diameter is concomitant with length fractionation, and nanotubes that have been cut shortest also possess the greatest relative enrichments of large-diameter species. Longer sonication time causes increased electrophoretic mobility in the gels; thus, ultrasonic processing determines the degree of both length and diameter separation of the nanotubes. The relative quantum yield decreases nonlinearly as the nanotube length becomes shorter. These techniques constitute a preparative, scalable method for separating nanotubes by two important attributes required for electronic and sensor applications.

Background: Health-related quality of life (HRQOL) is a key outcome in arthritis, but few population-based studies have examined the relationship of specific arthritic conditions, such as osteoarthritis (OA) and rheumatoid arthritis (RA) with HRQOL., Methods: Older adults in Pennsylvania completed a mail version of the Centers for Disease Control and Prevention (CDC) HRQOL modules. Medicare data were used to identify subjects with OA, RA, and no arthritis diagnosis. We compared HRQOL responses among these groups, and we also examined relationships of demographic characteristics to HRQOL among subjects with arthritis., Results: In analyses controlling for demographic characteristics and comorbidity, subjects with OA and RA had poorer scores than those without arthritis on all HRQOL items, including general health, physical health, mental health, activity limitation, pain, sleep, and feeling healthy and full of energy. HRQOL scores were also lower for those with RA compared to OA. Among individuals with arthritis, all subject characteristics (including age, race, sex, nursing home residence, marital status, income, and comorbid illnesses) were significantly related to at least one HRQOL item. Older age, nursing home residence, and greater comorbidity were the most consistently associated with poorer HRQOL., Conclusions: Results of this study show that both OA and RA have a significant impact on multiple dimensions of HRQOL among older adults. Results also suggest the CDC HRQOL items are suitable for use among older adults and in mail surveys. Due to the rising number of older adults in many countries, the public health burden of arthritis is expected to increase dramatically. Efforts are needed to enhance access to medical care and disseminate self-management interventions for arthritis.

Background: Nonsteroidal antiinflammatory drugs (NSAIDs) are the most commonly prescribed medications for the treatment of osteoarthritis (OA). Little is known about whether there are important gender differences in NSAID use among patients with OA., Objective: To examine gender differences in patterns of NSAID use among older adults (>or=65 y) with OA., Methods: Subjects (n = 11298) were members of a statewide prescription drug plan who responded to a health-related quality-of-life (HRQOL) survey in 1997 and had a physician diagnosis of OA. Gender differences in patterns of NSAID use were examined over a 2-year period., Results: Approximately one-third of the participants filled at least 1 NSAID prescription during the study. Women were significantly more likely to be prescribed an NSAID than men (37% vs. 30%), had a greater total days' supply of NSAIDs, and were more frequently prescribed NSAIDs with greater degrees of cyclooxygenase-2 selectivity. These gender differences persisted in statistical analyses controlling for demographic factors, HRQOL, and gastrointestinal (GI) risk factors., Conclusions: Results of this study showed significant gender differences in patterns of NSAID use, and these differences were independent of the risk for GI adverse effects and self-reported symptoms. Further research is needed to examine reasons for these gender variations, as well as their impact on the quality of symptom management.

Background and Aims: This investigation examined the ability of a four-item Health-Related Quality of Life (HRQOL) scale to predict short-term (30-day) and long-term (1-year) physician visits, hospitalization, and mortality among older adults., Methods: Subjects included 84065 individuals aged 65 and older who completed a mail version of the Centers for Diseases Control's Behavioral Risk Factor Surveillance System (BRFSS) Core HRQOL Module. HRQOL dimensions represented by the module include global self-rated general health, recent physical health, recent mental health, and recent activity limitation., Results: In analysis of covariance models controlling for demographic factors and comorbidity, the number of physician visits within 30 days and 1 year differed significantly across categories of each HRQOL item. In Cox regression models controlling for the same covariates, all four HRQOL questions were significant predictors of 30-day and 1-year hospitalization and mortality., Conclusions: These results signify that all four dimensions of HRQOL represented by the BRFSS Core HRQOL Module are important predictors of both short-term and long-term adverse health events among older adults. This brief scale may be particularly useful for assessing the health of older adults in clinical settings and large-scale epidemiological studies.

Background: Recent Food and Drug Administration-mandated and company-initiated withdrawals of drug products from the marketplace have had an impact on utilization in related drug classes., Objective: To investigate the impact of withdrawal of the prokinetic agent cisapride (Propulsid) on utilization of other gastrointestinal (GI) agents., Study Design: A longitudinal, retrospective study using electronic prescription data from a state-funded geriatric prescription benefit program., Patients and Methods: Prescription claims for 2644 patients using cisapride between January 10, 2000, and October 1, 2000, were analyzed with respect to points in time at which (1) prospective drug utilization review edits were implemented denying reimbursement of cisapride because of drug interactions, (2) the manufacturer announced its intent to cease production, and (3) the agent was withdrawn from the market. Prevalence of use, claims volume, and expenditures were compared for cisapride, proton pump inhibitors, histamine-2 receptor antagonists, and the prokinetic agent metoclopramide during these periods., Results: Use of cisapride decreased precipitately even before implementation of a "medical exception only" reimbursement policy. After the change in policy, metoclopramide use increased, although this increase was not proportional to cisapride's decline. Although total GI expenditures declined within the cisapride cohort, this change had little impact on overall program GI expenditures., Conclusions: The loss of cisapride did not significantly affect program-wide costs for GI drugs. However, the withdrawal of cisapride appears to have resulted in increased use of metoclopramide, a medication with a more serious adverse effect profile than cisapride. Further study is needed to evaluate the long-term clinical impact of such therapy changes.

Background: Results of recent studies suggest that beta-blockers are underused by elderly acute myocardial infarction (AMI) survivors. The goals of this study were to examine changes in post-AMI beta-blocker use occurring between 1994 and 1997 and to identify factors associated with outpatient use of beta-blockers., Methods: Patients included 9534 individuals >/=65 years of age who were enrolled in Pennsylvania's Pharmaceutical Assistance Contract for the Elderly (PACE) and who survived AMI between 1994 and 1997. With the use of outpatient prescription claims, beta-blocker usage rates were examined by year, and multivariate logistic regression was used to identify predictors of beta-blocker use., Results: Post-AMI beta-blocker use increased from 39.6% in 1994 to 58.6% in 1997. Controlling for AMI year, individuals who had any prescriptions written by a cardiologist were more likely to use a beta-blocker than individuals who received all prescriptions from noncardiologists (odds ratio 1.52, P =.0001). Elderly patients who did not use beta-blockers tended to have greater severity of illness, non-Q-wave infarctions, atrial fibrillation, and comorbidities such as congestive heart failure, chronic obstructive pulmonary disease, and asthma. Use of calcium channel blockers and diuretics was negatively associated with beta-blocker use, but persons using lipid-lowering agents were more likely to use beta-blockers., Conclusions: Significant improvements in beta-blocker use by elderly AMI survivors have occurred since 1994. Differences among physician specialties in beta-blocker prescribing appear to remain. Across all prescriber specialties, historic contraindications constitute major factors in the choice of post-AMI therapy. Further efforts should be made to encourage the use of beta-blockers in elderly survivors of AMI, particularly those with heart failure.

A longitudinal study was undertaken to evaluate the relationships among a battery of aging biomarkers and subsequent survival time in 319 genetically heterogenous stock (HS) mice. The biomarker variables chosen were selected from the broad domains of behavior, homeostatic physiology, oxidative defense, and immune function; biomarkers were measured at 45, 90, 360, 630, and 900 days of age. Sex differences were found in the survivor and mortality functions, with a mortality rate crossover occurring at about 525 days and a survival curve crossover at about 750 days of age. Females experienced lower initial mortality but had more sharply increasing mortality with age than did males. Survival analysis using Gompertz parametric models with biomarkers as time-varying covariates yielded significant biomarkers from each domain. Following backward elimination procedures, the final set of independent mortality predictors included headpokes in the File activity apparatus, maximum cord drop time, weight, hematocrit, urine concentration, natural killer cell activity, and concanavalin A response.

Two hundred and ninety four pairs of Swedish twins reared apart and twins reared together were used to evaluate the importance of genetic and environmental influences on lipoprotein(a) (Lp(a)) levels. Lp(a) levels ranged from <10 mg/l to 926 mg/l with 7.9% of the sample having undetectable Lp(a) levels (i.e. <10 mg/l). A substantial genetic component in Lp(a) variation was indicated by a heritability estimate of approximately 90%. No difference in heritability was found across age groups. Quantitative genetic analyses also suggest correlated environmental effects most likely composed of maternal, neonatal and postnatal environmental influences. However, these effects did not reach statistical significance, partly due to a lack of power. Results from analyses of co-twin differences in Lp(a) levels for monozygotic twins indicate that sex hormone use may be of importance for Lp(a) variation in women. There was no evidence of potential influences of alcohol consumption, beta-blocker and diuretic administration on Lp(a) levels in either men or women.

Genetic and environmental correlations among five serum-lipid measures were examined in the Swedish Adoption/Twin Study of Aging. The sample included 302 twin pairs; 146 of these twin pairs were separated at an early age and were reared apart. The lipid measures examined include total cholesterol, HDL-cholesterol, triglycerides, and apolipoproteins A-I and B. Genetic and environmental correlations were evaluated for two different age groups, formed by dividing the sample at the median. The younger group included individuals 41.8-65.4 years of age at the midpoint of testing, although only 24 individuals were < 50 years of age. The older group included all those > 65.4 years of age, up to age 87 years of age. Substantial genetic correlations were found within each age group, although there is no evidence for a single genetic factor common to all five lipids. The comparison of twins reared together with twins reared apart allowed estimation of the effects of shared rearing environment; however, shared rearing environment only appears to be a significant mediator of the phenotypic correlation between apolipoprotein B and cholesterol in the older group. Examination of the genetic and environmental covariances suggests that the relative contributions of genetic factors are lower in the older group. Nonshared environmental factors are relatively more important mediators of phenotypic correlations among the serum lipids in individuals > 65.4 years of age than they are for the younger group. Sex differences in the mediation of these serum lipids were not as clear.

We used 289 pairs of Swedish twins reared apart or together to evaluate the importance of genetic and environmental influences on blood pressure. Unlike other twin and family studies, the adoption/twin design allows a distinction between estimates of the importance of shared rearing environments and genetic effects. Genetic factors were observed to play an important role for individual differences in blood pressure. Model-fitting analyses suggested upper limits of heritability for systolic and diastolic blood pressures in the entire sample of 0.44 and 0.34, respectively. More interestingly, substantial influences of shared family effects accounting for up to 27% of the variation were also revealed. Effects of correlated environment, which might reflect, for example, the intrauterine environment, existed to some extent later in life. The influence of genetic factors tended to decrease across age groups for systolic blood pressure (0.62 in individuals less than 65 years old; 0.12 in those 65 years and older) but not for diastolic blood pressure (0.22 for the middle-aged group; 0.26 for the older group). However, this declining trend for systolic blood pressure did not reach significance (chi 2 = 8.07, df = 4, P = .09).

Background: In addition to their value in assessing pulmonary health and disease, spirometric variables have been shown to be powerful predictors of time until death in aging populations. The sources of variability in these spirometric values are consequently of relevance to basic gerontological research, and also of potential value in clinical application. The objective of this study was to estimate genetic and environmental sources of variance in pulmonary function., Methods: The study involved 230 Swedish twin pairs (mean age = 64.9 years), of which number 37 monozygotic (MZ) pairs and 72 dizygotic (DZ) pairs had been separated and reared apart. Comparing these groups to the 57 MZ and 64 DZ pairs reared together permits stronger interpretation than that of conventional twin studies. Measures of vital capacity (VC) and forced expiratory volume in one second (FEV1) were residualized for height, age, sex, and tobacco consumption in pack-years., Results: Maximum likelihood analyses of VC and FEV1 gave heritability estimates of .48 and .67, respectively. Age effects were explored both by dividing the sample into two cohorts, respectively above and below 65 years, and by moving interval analysis. In the two-cohort analysis, heritabilities were somewhat higher for the older cohort than the younger cohort for FEV1. The opposite was true for VC: heritability was lower in the older cohort, and there was evidence for a shared rearing environmental effect for this group. Moving interval analysis suggests these differences are gradual rather than saltatory. There were no gender differences in parameter estimates., Conclusion: Genetic factors account for between one-half and two-thirds of the variability in pulmonary function. There is a suggestion of age differences in the relative importance of genetic and environmental influences.

Background: The extent to which serum lipid levels are affected by genetic and environmental factors remains a point of controversy. We examined both genetic and environmental influences on serum lipid levels in twins reared either together or apart who participated in the Swedish Adoption/Twin Study of Aging., Methods: We studied 302 pairs of twins (mean age, 65.6 years; range, 52 to 86); 146 pairs had been reared apart. We simultaneously compared the twins on the basis of both zygosity and rearing status, which allowed joint estimation of genetic and environmental influences on serum lipid levels. Genetic influence was expressed in terms of heritability, the proportion of the population variation attributable to genetic variation (a value of 1.0 indicates that all of the population variation is attributable to genetic variation). The serum lipids and apolipoproteins measured included total cholesterol, high-density lipoprotein cholesterol, apolipoproteins A-I and B, and triglycerides., Results: Structural-equation analyses revealed substantial heritability for the serum levels of each lipid measured, ranging from 0.28 to 0.78. Comparisons of the twins reared together with those reared apart suggested that the environment of rearing had a substantial impact on the level of total cholesterol (accounting for 0.15 to 0.36 of the total variance). Sharing the same environment appeared to affect the other lipid measures much less, however, than did genetic factors and unique environmental factors not shared by twins. Comparisons of younger with older twins suggested that heritability for apolipoprotein B and triglyceride levels decreased with age., Conclusions: The effect of genetic factors on the serum levels of some but not all lipids appears to decrease with age. Early rearing environment appears to remain an important factor in relation to levels of total cholesterol later in life, but it has less effect on other serum lipids and apolipoproteins in the elderly.

Tail tendon fibre break time (TTFBT), an indicator of collagen cross-linkage, was measured longitudinally in C57BL/6, DBA/2 and B6D2F1 mice, and F2 and backcross genotypes. TTFBT was assessed at 50, 150, 300 and 450 days of age. The distribution of means of these six genotypes suggests substantial genetic influence on this phenotype. Broad sense heritability, as assessed in a classical biometrical analysis, was negligible at 50 and 150 days, but accounted for between 25 and 43% of the variance at 300 to 450 days. The stability and reliability of TTFBT were also examined. Reliability was extremely high for each occasion; stability increased from moderate to substantial levels with increasing age, and may be influenced by heterozygosity.

Individual variability in mouse tail tendon fiber denaturation in urea was investigated. Differences in break time between fibers within tendons and between tendon groups were examined. Mean break times for each strain increased with age with the shorter-lived DBA/2 mice exhibiting higher break times within age cohorts than the C57BL/6 animals. Fibers from the two ventral tendon groups had consistently higher break times than those from the two dorsal groups, implying differential rates of collagen maturation between these two areas within the tail. Histological examination revealed conspicuous morphological dorsal/ventral differences in tendon number, proximity to a major blood vessel, and the amount of surrounding muscle tissue. These findings have methodological and experimental design implications for the use of tail tendon break time (TTBT) as a biomarker of aging. Furthermore, they suggest possible physiological mechanisms for differential rates of collagen aging.