Let’s Talk Takataka: Impacts of Plastic in the Stone Town Harbor Area, Zanzibar

Plastic pollution has become an anthropogenic crisis worldwide. In the Stone Town Harbor area in particular, consumerism, population growth, tourism and a deficient municipal waste management system contribute to alarming amounts of mismanaged plastic that enter the ocean. This is devastating for the diverse marine ecosystem that provides valuable resources to its flora and fauna and to it human inhabitants. In this study, micro-plastic at the sea surface as well as plastic on coastal beaches was quantified to determine the effects of plastic pollution in the area by use of a standard plankton net methodology. This study contributed to the first set of baseline information regarding plastic at this location. It was determined that there are approximately 172,061.01 micro-plastic floating particles at the sea surface in the Stone Town Harbor area. Micro-plastic was found in 94% of sea surface samples and plastic was found in 64.76% of coastal beach survey quadrats. Results suggest that the population size in this coastal environment is proportional to the micro- and macro-plastic abundance in the area. Furthermore, if the population of Stone Town limited single-use plastic, it would greatly mitigate plastic waste concentration, including by up to 43%. This study will contribute to plastic waste awareness as well as offer recommendations for more successful waste management strategies the help conserve the marine ecosystem

Temporomandibular joint prosthesis in cancer reconstruction preceding radiation therapy

Total joint prostheses are a viable treatment option after removal of malignancies invading the temporomandibular joint, even when adjuvant radiation therapy is required.publishedVersio

Visualizing Rank Deficient Models: A Row Equation Geometry of Rank Deficient Matrices and Constrained-Regression

Situations often arise in which the matrix of independent variables is not of full column rank. That is, there are one or more linear dependencies among the independent variables. This paper covers in detail the situation in which the rank is one less than full column rank and extends this coverage to include cases of even greater rank deficiency. The emphasis is on the row geometry of the solutions based on the normal equations. The author shows geometrically how constrained-regression/generalized-inverses work in this situation to provide a solution in the face of rank deficiency

Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease

Monthly quasi-periodic eruptions from repeated stellar disruption by a massive black hole

In recent years, searches of archival X-ray data have revealed galaxies exhibiting nuclear quasi-periodic eruptions with periods of several hours. These are reminiscent of the tidal disruption of a star by a supermassive black hole. The repeated, partial stripping of a white dwarf in an eccentric orbit around an ~105 M⊙ black hole provides an attractive model. A separate class of periodic nuclear transients, with much longer timescales, have recently been discovered optically and may arise from the partial stripping of a main-sequence star by an ~107 M⊙ black hole. No clear connection between these classes has been made. We present the discovery of an X-ray nuclear transient that shows quasi-periodic outbursts with a period of weeks. We discuss possible origins for the emission and propose that this system bridges the two existing classes outlined above. This discovery was made possible by the rapid identification, dissemination and follow-up of an X-ray transient found by the new live Swift-XRT transient detector, demonstrating the importance of low-latency, sensitive searches for X-ray transients

Reactive oxygen species initiate luminal but not basal cell death in cultured human mammary alveolar structures: a potential regulator of involution

Post-lactational involution of the mammary gland is initiated within days of weaning. Clearing of cells occurs by apoptosis of the milk-secreting luminal cells in the alveoli and through stromal tissue remodeling to return the gland almost completely to its pre-pregnant state. The pathways that specifically target involution of the luminal cells in the alveoli but not the basal and ductal cells are poorly understood. In this study we show in cultured human mammary alveolar structures that the involution process is initiated by fresh media withdrawal, and is characterized by cellular oxidative stress, expression of activated macrophage marker CD68 and finally complete clearing of the luminal but not basal epithelial layer. This process can be simulated by ectopic addition of reactive oxygen species (ROS) in cultures without media withdrawal. Cells isolated from post-involution alveoli were enriched for the CD49f+ mammary stem cell (MaSC) phenotype and were able to reproduce a complete alveolar structure in subcultures without any significant loss in viability. We propose that the ROS produced by accumulated milk breakdown post-weaning may be the mechanism underlying the selective involution of secretory alveolar luminal cells, and that our culture model represents an useful means to investigate this and other mechanisms further

Decision-making and referral processes for patients with motor neurone disease: a qualitative study of GP experiences and evaluation of a new decision-support tool

Background The diagnosis of motor neurone disease (MND) is known to be challenging and there may be delay in patients receiving a correct diagnosis. This study investigated the referral process for patients who had been diagnosed with MND, and whether a newly-developed tool (The Red Flags checklist) might help General Practitioners (GPs) in making referral decisions. Methods We carried out interviews with GPs who had recently referred a patient diagnosed with MND, and interviews/surveys with GPs who had not recently referred a patient with suspected MND. We collected data before the Red Flags checklist was introduced; and again one year later. We analysed the data to identify key recurring themes. Results Forty two GPs took part in the study. The presence of fasciculation was the clinical feature that most commonly led to consideration of a potential MND diagnosis. GPs perceived that their role was to make onward referrals rather than attempting to make a diagnosis, and delays in correct diagnosis tended to occur at the specialist level. A quarter of participants had some awareness of the newly-developed tool; most considered it useful, if incorporated into existing systems. Conclusions While fasciculation is the most common symptom associated with MND, other bulbar, limb or respiratory features, together with progression should be considered. There is a need for further research into how decision-support tools should be designed and provided, in order to best assist GPs with referral decisions. There is also a need for further work at the level of secondary care, in order that referrals made are re-directed appropriately

Inhibition of the tyrosine phosphatase SHP-2 suppresses angiogenesis in vitro and in vivo

Endothelial cell survival is indispensable to maintain endothelial integrity and initiate new vessel formation. We investigated the role of SHP-2 in endothelial cell survival and angiogenesis in vitro as well as in vivo. SHP-2 function in cultured human umbilical vein and human dermal microvascular endothelial cells was inhibited by either silencing the protein expression with antisense-oligodesoxynucleotides or treatment with a pharmacological inhibitor (PtpI IV). SHP-2 inhibition impaired capillary-like structure formation (p < 0.01; n = 8) in vitro as well as new vessel growth ex vivo (p < 0.05; n = 10) and in vivo in the chicken chorioallantoic membrane (p < 0.01, n = 4). Additionally, SHP-2 knock-down abrogated fibroblast growth factor 2 (FGF-2)-dependent endothelial proliferation measured by MTT reduction ( p ! 0.01; n = 12). The inhibitory effect of SHP-2 knock-down on vessel growth was mediated by increased endothelial apoptosis ( annexin V staining, p ! 0.05, n = 9), which was associated with reduced FGF-2-induced phosphorylation of phosphatidylinositol 3-kinase (PI3-K), Akt and extracellular regulated kinase 1/2 (ERK1/2) and involved diminished ERK1/2 phosphorylation after PI3-K inhibition (n=3). These results suggest that SHP-2 regulates endothelial cell survival through PI3-K-Akt and mitogen-activated protein kinase pathways thereby strongly affecting new vessel formation. Thus, SHP-2 exhibits a pivotal role in angiogenesis and may represent an interesting target for therapeutic approaches controlling vessel growth. Copyright (C) 2007 S. Karger AG, Basel

Respiratory modulation of oscillometric cuff pressure pulses and Korotkoff sounds during clinical blood pressure measurement in healthy adults

BACKGROUND: Accurate blood pressure (BP) measurement depends on the reliability of oscillometric cuff pressure pulses (OscP) and Korotkoff sounds (KorS) for automated oscillometric and manual techniques. It has been widely accepted that respiration is one of the main factors affecting BP measurement. However, little is known about how respiration affects the signals from which BP measurement is obtained. The aim was to quantify the modulation effect of respiration on oscillometric pulses and KorS during clinical BP measurement. METHODS: Systolic and diastolic BPs were measured manually from 40 healthy subjects (from 23 to 65 years old) under normal and regular deep breathing. The following signals were digitally recorded during linear cuff deflation: chest motion from a magnetometer to obtain reference respiration, cuff pressure from an electronic pressure sensor to derive OscP, and KorS from a digital stethoscope. The effects of respiration on both OscP and KorS were determined from changes in their amplitude associated with respiration between systole and diastole. These changes were normalized to the mean signal amplitude of OscP and KorS to derive the respiratory modulation depth. Reference respiration frequency, and the frequencies derived from the amplitude modulation of OscP and KorS were also calculated and compared. RESULTS: Respiratory modulation depth was 14 and 40 % for OscP and KorS respectively under normal breathing condition, with significant increases (both p  0.05) during deep breathing, and for the oscillometric signal during normal breathing (p > 0.05). CONCLUSIONS: Our study confirmed and quantified the respiratory modulation effect on the oscillometric pulses and KorS during clinical BP measurement, with increased modulation depth under regular deeper breathing

Preclinical efficacy studies of a novel nanoparticle-based formulation of paclitaxel that out-performs Abraxane

Poly-(γ-l-glutamylglutamine)–paclitaxel (PGG–PTX) is a novel polymer-based formulation of paclitaxel (PTX) in which the PTX is linked to the polymer via ester bonds. PGG–PTX is of interest because it spontaneously forms very small nanoparticles in plasma. In mouse models, PGG–PTX increased tumor exposure to PTX by 7.7-fold relative to that produced by PTX formulated in Cremophor. In this study, the efficacy of PGG–PTX was compared to that of Abraxane, an established nanoparticular formulation of PTX, in three different tumor models. Efficacy was quantified by delay in tumor growth of NCI H460 human lung cancer, 2008 human ovarian cancer and B16 melanoma xenografts growing in athymic mice following administration of equitoxic doses of PGG–PTX and Abraxane administered on either a single dose or every 7 day schedule. Toxicity was assessed by change in total body weight. The efficacy and toxicity of PGG–PTX was shown to increase with dose in the H460 model. PGG–PTX was ~1.5-fold less potent than Abraxane. PGG–PTX produced statistically significantly greater inhibition of tumor growth than Abraxane in all three tumor models when mice were given single equitoxic doses of drug. When given every 7 days for 3 doses, PGG–PTX produced greater inhibition of tumor growth while generating much less weight loss in mice bearing H460 tumors. PGG–PTX has activity that is superior to that of Abraxane in multiple tumor models. PGG–PTX has the potential to out-perform Abraxane in enhancing the delivery of PTX tumors while at the same time further reducing the toxicity of both single dose and weekly treatment regimens