"Alternative" endocytic mechanisms exploited by pathogens: new avenues for therapeutic delivery?

Some pathogens utilize unique routes to enter cells that may evade the intracellular barriers encountered by the typical clathrin-mediated endocytic pathway. Retrograde transport and caveolar uptake are among the better characterized pathways, as alternatives to clathrin-mediated endocytosis, that are known to facilitate entry of pathogens and potential delivery agents. Recent characterization of the trafficking mechanisms of prion proteins and certain bacteria may present new paradigms for strategizing improvements in therapeutic spread and retention of therapy. This review will provide an overview of such endocytic pathways, and discuss current and future possibilities in using these routes as a means to improve therapeutic delivery

Effects of Cervical Spine Manipulation on Balance and Joint Proprioception in Asymptomatic Individuals: Plausibility and Pilot Study

Background: Balance issues are prevalent in all ages of the population and can lead to many debilitating secondary impairments. There are various methods for treating balance problems, one of which is cervical spine manipulation (CSM). It seems to be biologically plausible that CSM would be an effective intervention, as it elicits effects in the same systems that are impaired in people with balance issues: vestibular, visual, and somatosensory. Objective: The aim of this study is to investigate the immediate differences in balance and proprioception following a CSM in asymptomatic subjects. Design: An experimental, cross-over study design was used Methods: Thirty-four eligible asymptomatic volunteers (mean age 25.0 years old) with no current neck pain, neck pain within the past 6 months, balance disorders, or vertebral artery insufficiency participated. Participants came for testing 2 times; once for the sham procedure and once for the CSM procedure. The order in which the participant received their interventions was randomly assigned. Balance was assessed prior to and immediately following the CSM intervention and sham procedure using the SMART NeuroCom Balance Master™ Sensory Organization Test (SOT) and Laser Cervical Proprioceptive test (LCPT). Investigators conducting the tests were blinded to which intervention the participant had received. Results: There was a statistically significant main effect of time for the LCPT scores in the overall sample (F(1,33)=4.780, p=0.036, Power=.565). There was also a statistically significant main effect of time for the vestibular component of the SOT (F(1,33)=5.333, p=0.027, Power=.611) and the main effect of intervention for the somatosensory component of SOT (F(1,33)=5.554, p=0.025, Power=.628). There was no significant difference between gross pre and post scores between test groups for the LCPT total error, (F(1,33)=1.221, p=.277, Power 0.189. No significant difference was found between composite SOT scores pre and post intervention (F(1,33)=0.205, p=0.654, Power 0.072 . For the individual components of balance no significant interaction was found: somatosensory, (F(1,33)=0.370, p=0.547 Power 0.091; vestibular, F(1,33)=0.126, p=0.725, Power 0.064; visual, F(1,33)=0.054, p=0.818, Power 0.056). Limitations: The main limitations in this study were the small sample size, ceiling effect with SOT testing, and unestablished reliability and validity of the LCPT. Conclusions: It has been shown that it is biologically plausible for CSM to evoke changes in people with balance disorders based off of proposed mechanisms and established research. Although this research was unable to capture changes in balance and proprioception following CSM, it would benefit this body of literature to repeat the design with more sensitive and valid outcome measures

Ratiometric spectral imaging for fast tumor detection and chemotherapy monitoring in vivo

We report a novel in vivo spectral imaging approach to cancer detection and chemotherapy assessment. We describe and characterize a ratiometric spectral imaging and analysis method and evaluate its performance for tumor detection and delineation by quantitatively monitoring the specific accumulation of targeted gallium corrole (HerGa) into HER2-positive (HER2 +) breast tumors. HerGa temporal accumulation in nude mice bearing HER2 + breast tumors was monitored comparatively by a. this new ratiometric imaging and analysis method; b. established (reflectance and fluorescence) spectral imaging; c. more commonly used fluorescence intensity imaging. We also tested the feasibility of HerGa imaging in vivo using the ratiometric spectral imaging method for tumor detection and delineation. Our results show that the new method not only provides better quantitative information than typical spectral imaging, but also better specificity than standard fluorescence intensity imaging, thus allowing enhanced in vivo outlining of tumors and dynamic, quantitative monitoring of targeted chemotherapy agent accumulation into them

Investigating photoexcitation-induced mitochondrial damage by chemotherapeutic corroles using multimode optical imaging

We recently reported that a targeted, brightly fluorescent gallium corrole (HerGa) is highly effective for breast tumor detection and treatment. Unlike structurally similar porphryins, HerGa exhibits tumor-targeted toxicity without the need for photoexcitation. We have now examined whether photoexcitation further modulates HerGa toxicity, using multimode optical imaging of live cells, including two-photon excited fluorescence, differential interference contrast (DIC), spectral, and lifetime imaging. Using two-photon excited fluorescence imaging, we observed that light at specific wavelengths augments the HerGa-mediated mitochondrial membrane potential disruption of breast cancer cells in situ. In addition, DIC, spectral, and fluorescence lifetime imaging enabled us to both validate cell damage by HerGa photoexcitation and investigate HerGa internalization, thus allowing optimization of light dose and timing. Our demonstration of HerGa phototoxicity opens the way for development of new methods of cancer intervention using tumor-targeted corroles

Multimodality imaging in vivo for preclinical assessment of tumor-targeted doxorubicin nanoparticles.

This study presents a new multimodal imaging approach that includes high-frequency ultrasound, fluorescence intensity, confocal, and spectral imaging to improve the preclinical evaluation of new therapeutics in vivo. Here we use this approach to assess in vivo the therapeutic efficacy of the novel chemotherapy construct, HerDox during and after treatment. HerDox is comprised of doxorubicin non-covalently assembled in a viral-like particle targeted to HER2+ tumor cells, causing tumor cell death at over 10-fold lower dose compared to the untargeted drug, while sparing the heart. Whereas our initial proof-of-principle studies on HerDox used tumor growth/shrinkage rates as a measure of therapeutic efficacy, here we show that multimodal imaging deployed during and after treatment can supplement traditional modes of tumor monitoring to further characterize the particle in tissues of treated mice. Specifically, we show here that tumor cell apoptosis elicited by HerDox can be monitored in vivo during treatment using high frequency ultrasound imaging, while in situ confocal imaging of excised tumors shows that HerDox indeed penetrated tumor tissue and can be detected at the subcellular level, including in the nucleus, via Dox fluorescence. In addition, ratiometric spectral imaging of the same tumor tissue enables quantitative discrimination of HerDox fluorescence from autofluorescence in situ. In contrast to standard approaches of preclinical assessment, this new method provides multiple/complementary information that may shorten the time required for initial evaluation of in vivo efficacy, thus potentially reducing the time and cost for translating new drug molecules into the clinic

Temperature responses of photosynthesis and respiration in evergreen trees from boreal to tropical latitudes

Evergreen species are widespread across the globe, representing two major plant functional forms in terrestrial models. We reviewed and analysed the responses of photosynthesis and respiration to warming in 101 evergreen species from boreal to tropical biomes. Summertime temperatures affected both latitudinal gas exchange rates and the degree of responsiveness to experimental warming. The decrease in net photosynthesis at 25 degrees C (A(net25)) was larger with warming in tropical climates than cooler ones. Respiration at 25 degrees C (R-25) was reduced by 14% in response to warming across species and biomes. Gymnosperms were more sensitive to greater amounts of warming than broadleaved evergreens, with A(net25) and R-25 reduced c. 30-40% with > 10 degrees C warming. While standardised rates of carboxylation (V-cmax25) and electron transport (J(max25)) adjusted to warming, the magnitude of this adjustment was not related to warming amount (range 0.6-16 degrees C). The temperature optimum of photosynthesis (T-optA) increased on average 0.34 degrees C per degrees C warming. The combination of more constrained acclimation of photosynthesis and increasing respiration rates with warming could possibly result in a reduced carbon sink in future warmer climates. The predictable patterns of thermal acclimation across biomes provide a strong basis to improve modelling predictions of the future terrestrial carbon sink with warming

Tumor detection and elimination by a targeted gallium corrole

Sulfonated gallium(III) corroles are intensely fluorescent macrocyclic compounds that spontaneously assemble with carrier proteins to undergo cell entry. We report in vivo imaging and therapeutic efficacy of a tumor-targeted corrole noncovalently assembled with a heregulin-modified protein directed at the human epidermal growth factor receptor (HER). Systemic delivery of this protein-corrole complex results in tumor accumulation, which can be visualized in vivo owing to intensely red corrole fluorescence. Targeted delivery in vivo leads to tumor cell death while normal tissue is spared. These findings contrast with the effects of doxorubicin, which can elicit cardiac damage during therapy and required direct intratumoral injection to yield similar levels of tumor shrinkage compared with the systemically delivered corrole. The targeted complex ablated tumors at >5 times a lower dose than untargeted systemic doxorubicin, and the corrole did not damage heart tissue. Complexes remained intact in serum and the carrier protein elicited no detectable immunogenicity. The sulfonated gallium(III) corrole functions both for tumor detection and intervention with safety and targeting advantages over standard chemotherapeutic agents

Examining the sensitivity of the terrestrial carbon cycle to the expression of El Niño

The El Niño - Southern Oscillation (ENSO) influences the global climate and the variability in the terrestrial carbon cycle on interannual timescales. Two different expressions of El Niño have recently been identified: (i) central Pacific (CP) and (ii) eastern Pacific (EP). Both types of El Niño are characterised by above-average sea surface temperature anomalies at the respective locations. Studies exploring the impact of these expressions of El Niño on the carbon cycle have identified changes in the amplitude of the concentration of interannual atmospheric carbon dioxide (CO2) variability following increased tropical near-surface air temperature and decreased precipitation. We employ the dynamic global vegetation model LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator) within a synthetic experimental framework to examine the sensitivity and potential long-term impacts of these two expressions of El Niño on the terrestrial carbon cycle. We manipulated the occurrence of CP and EP events in two climate reanalysis datasets during the latter half of the 20th and early 21st century by replacing all EP with CP and separately all CP with EP El Niño events. We found that the different expressions of El Niño affect interannual variability in the terrestrial carbon cycle. However, the effect on longer timescales was small for both climate reanalysis datasets. We conclude that capturing any future trends in the relative frequency of CP and EP El Niño events may not be critical for robust simulations of the terrestrial carbon cycle