Grewia gum 2:mucoadhesive properties of compacts and gels

Purpose: To compare the mucoadhesive performance of grewia polysaccharide gum with those of guar gum, carboxymethylcellulose, hydroxypropyl methylcellulose and carbopol 971P. Methods: Grewia polysaccharide gum compacts or gels as well as those of guar gum, carboxymethylcellulose, hydroxypropyl methylcellulose or carbopol 971P were prepared. Texturometric and tensile analysis of the polymer gels and compacts were carried out using a software-controlled penetrometre, TA.XTPlus texture analyzer. The polymer gels were evaluated for hardness, stickiness, work of cohesion and work of adhesion. Furthermore, the detachment force of the polymer compacts from a mucin substrate was evaluated. Results: The work of adhesion of guar gels was significantly greater than that of grewia gels (p < 0.001) but the latter showed a significantly greater work of adhesion than carboxymethylcellulose gels (p < 0.05) and hydroxypropyl methylcellulose gels (p < 0.001). However, the work of cohesion for grewia/mucin gel mixture was significantly greater (p < 0.001) than those of carboxymethylcellulose/mucin, hydroxypropyl methylcellulose/mucin and carbopol 971P/mucin gel blends. The difference between the mucoadhesive performance of grewia compacts and those of hydroxypropyl methylcellulose and carbopol 971P compacts was insignificant (p > 0.05). Conclusion: Grewia polysaccharide gum demonstrated good mucoadhesive properties, comparable to those of carbopol 971P, carboxymethylcellulose, guar gum and hydroxypropyl methylcellulose, and therefore, should be suitable for the formulation of retentive drug delivery devices. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City.

Physicochemical characterization of grewia polysaccharide gum:effect of drying method

Grewia polysaccharide gum, a potential pharmaceutical excipient was extracted from the inner stem bark of Grewia mollis, thereupon drying was achieved by three techniques: air-drying, freeze-drying and spray-drying. Analysis of the monosaccharide composition including 1H and 13C NMR spectroscopic analysis of the polysaccharide gum was carried out. The effect of the drying methods on the physicochemical properties of the gum was evaluated by Fourier transformed infra-red (FT-IR) spectroscopy, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, differential scanning calorimetry and gel permeation chromatography. Monosaccharide sugar analysis revealed that the gum is composed of glucose, rhamnose, galactose, arabinose and xylose as the main neutral sugars. These were supported by the results from 1H and 13C NMR spectroscopic analysis. FT-IR and solid-state NMR results indicated that drying technique has little effect on the structure of the polysaccharide gum but XPS showed that surface chemistry of the gum varied with drying methods. Thermogravimetric analyses showed that oxidation onset varied according to the drying method. The molecular weight was also dependent on the drying technique. For industrial extrapolation, air-drying may be preferable to spray-drying and freeze-drying when relative cost, product stability and powder flow are required, for example in tablet formulation. © 2010 Elsevier Ltd. All rights reserved.

Characterization of Grewia gum, a potential pharmaceutical excipient

Grewia gum was extracted from the inner stem bark of Grewia mollis and characterized by several techniques such as gas chromatography (GC), gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis of the extracted sample. Spectroscopic techniques such as x-ray photoelectron spectroscopy (XPS), fourier-transformed infrared (FT-IR), solid-state nuclear magnetic resonance (NMR), and 1H and 13C NMR techniques were also used to characterize the gum. The results showed that grewia gum is a typically amorphous polysaccharide gum containing glucose, rhamnose, galactose, arabinose and xylose as neutral sugars. It has an average molecular weight of 5925 kDa expressed as the pullulan equivalent. The gum slowly hydrated in water, dispersing and swelling to form a highly viscous dispersion exhibiting pseudoplastic flow behaviour. The polysaccharide gum is thermally stable and may have application as stabilizer or suspending agent in foods, cosmetics and in pharmaceuticals. It may have application as a binder or sustained-release polymer matrix in tablets or granulations. © IPEC-Americas Inc.

Lily with bubble gum

General note: Title and date provided by Bettye Lane.

Development of the edible blend films with good mechanical and barrier properties from pea starch and guar gum

The individual and interactive impacts of guar gum and glycerol on the pea starch-based edible film characteristics were examined using three factors with three level Box–Behnken response surface design. The results showed that density and elongation at break were only significantly (p < 0.05) affected by pea starch and guar gum in a positive linear fashion. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on thickness, density, puncture force, water vapour permeability, and tensile strength. While tensile strength and Young modulus affected by the quadratic regression coefficient of glycerol and guar gum, respectively. The results were analysed using Pareto analysis of variance (ANOVA) and the developed predictive equations for each response variable presented reliable and satisfactory fit with high coefficient of determination (R2) values (≥ 0.96). The optimized conditions with the goal of maximizing mechanical properties and minimizing water vapour permeability were 2.5 g pea starch, 0.3 g guar gum and 25 % (w/w) glycerol based on the dry film matter in 100 ml of distilled water. Generally, changes in the concentrations of pea starch, guar gum and glycerol resulted in changes in the functional properties of film.

Determinants of alcohol use and khat chewing among Hawassa University students, Ethiopia: a cross sectional study.

Background: Students’ alcohol and khat use have been associated with various health related problems. However, its magnitude and associated factors among Ethiopian students are not yet well documented. Objective: The study aimed to assess the prevalence of alcohol use, khat chewing and its associated factors among Hawassa University students. Methods: A cross-sectional study was conducted from June to July 2011. Multistage stratified sampling technique was employed to select 590 students. Self administered questionnaires were used to collect data. Data was entered and analysed by SPSS version 20.0. Logistic regression analyses were used to identify the association of different variables. Results: The current prevalence of student’s alcohol and khat use were 29.5% (95% CI: 25.8-33.3) and 16.3% (95% CI: 13.7- 20.0) respectively. Being male (AOR 1.8; 95% CI 1.1-3.0) and living alone (AOR 20.1; 95% CI 2.5-166.7) had a higher odds of alcohol use. Similarly, family substance use history (AOR 4.8; 95% CI 2.5-9.3) and peer influence (AOR 4.6; 95% CI 2.3-9.0) had also higher odds of khat use. Conclusion and recommendation: The proportion of student’s khat chewing and alcohol use was significant. Hence, higher education in collaboration with other stakeholders should work on convincing students about the ill effects of these substances.

Development of Locust Bean Gum Nanoparticles for protein delivery

Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2014

Inhalable antitubercular therapy mediated by locust bean gum microparticles

Tuberculosis remains a major global health problem and alternative therapeutic approaches are needed. Considering the high prevalence of lung tuberculosis (80% of cases), the pulmonary delivery of antitubercular drugs in a carrier system capable of reaching the alveoli, being recognised and phagocytosed by alveolar macrophages (mycobacterium hosts), would be a significant improvement to current oral drug regimens. Locust bean gum (LBG) is a polysaccharide composed of galactose and mannose residues, which may favour specific recognition by macrophages and potentiate phagocytosis. LBG microparticles produced by spray-drying are reported herein for the first time, incorporating either isoniazid or rifabutin, first-line antitubercular drugs (association efficiencies >82%). Microparticles have adequate theoretical properties for deep lung delivery (aerodynamic diameters between 1.15 and 1.67 μm). The cytotoxic evaluation in lung epithelial cells (A549 cells) and macrophages (THP-1 cells) revealed a toxic effect from rifabutin-loaded microparticles at the highest concentrations, but we may consider that these were very high comparing with in vivo conditions. LBG microparticles further evidenced strong ability to be captured by macrophages (percentage of phagocytosis >94%). Overall, the obtained data indicated the potential of the proposed system for tuberculosis therapy.

Mathematical-modelling simulation of red gum lerp psyllid Glycaspis brimblecombei population dynamics towards the strategy identification for biological control with its parasitoid Psyllaephagus bliteus.

2009

Particle number and mass emission factors from combustion of wood samples collected from Queensland forest

Knowledge of particle emission characteristics associated with forest fires and in general, biomass burning, is becoming increasingly important due to the impact of these emissions on human health. Of particular importance is developing a better understanding of the size distribution of particles generated from forest combustion under different environmental conditions, as well as provision of emission factors for different particle size ranges. This study was aimed at quantifying particle emission factors from four types of wood found in South East Queensland forests: Spotted Gum (Corymbia citriodora), Red Gum (Eucalypt tereticornis), Blood Gum (Eucalypt intermedia), and Iron bark (Eucalypt decorticans); under controlled laboratory conditions. The experimental set up included a modified commercial stove connected to a dilution system designed for the conditions of the study. Measurements of particle number size distribution and concentration resulting from the burning of woods with a relatively homogenous moisture content (in the range of 15 to 26 %) and for different rates of burning were performed using a TSI Scanning Mobility Particle Sizer (SMPS) in the size range from 10 to 600 nm and a TSI Dust Trak for PM2.5. The results of the study in terms of the relationship between particle number size distribution and different condition of burning for different species show that particle number emission factors and PM2.5 mass emission factors depend on the type of wood and the burning rate; fast burning or slow burning. The average particle number emission factors for fast burning conditions are in the range of 3.3 x 1015 to 5.7 x 1015 particles/kg, and for PM2.5 are in the range of 139 to 217 mg/kg.

A qualitative study of the experience of oral cancer among Taiwanese men

The incidence and mortality of oral cancer in Taiwanese men have increased over the past decade, primarily associated with a surge in the popularity of betel quid chewing. The aim of this study was to examine the experience of six Taiwanese men with oral cancer, who were aged between 40 and 60 years, using a qualitative approach. The three major themes emerging from the data include: (i) understanding the cancer diagnosis; (ii) the challenges of cancer treatment; and (iii) adapting to difference. Increasing nurses' understanding of the experiential aspects of oral cancer in this population is required if nurses are to develop successful health promotion programmes and nursing interventions to meet these patients' needs.

Drag coefficient in a crystal suspension

A single air bubble rising in xanthan gum crystal suspension has been studied experimentally. The suspension was made by different concentrations of xanthan gum solutions with 0.23 mm polystyrene crystal particles. Drag co-efficient data and a new correlation of drag coefficient is presented for spherical and nonspherical bubbles in non-Newtonian crystal suspension. The correlation is developed in terms of the Reynolds number, Re and the bubble shape factor, � (the ratio between the surface equivalent sphere diameter to the volume equivalent sphere diameter). The experimental drag coefficient was found to be consistent with this new predicted correlation and published data over the ranges, 0.1

Cancer risk in persons with HIV/AIDS in India: a review and future directions for research

Background India has a large and evolving HIV epidemic. Little is known about cancer risk in Indian persons with HIV/AIDS (PHA) but risk is thought to be low. Methods To describe the state of knowledge about cancer patterns in Indian PHA, we reviewed reports from the international and Indian literature. Results As elsewhere, non-Hodgkin lymphomas dominate the profile of recognized cancers, with immunoblastic/large cell diffuse lymphoma being the most common type. Hodgkin lymphoma is proportionally increased, perhaps because survival with AIDS is truncated by fatal infections. In contrast, Kaposi sarcoma is rare, in association with an apparently low prevalence of Kaposi sarcoma-associated herpesvirus. If confirmed, the reasons for the low prevalence need to be understood. Cervical, anal, vulva/vaginal and penile cancers all appear to be increased in PHA, based on limited data. The association may be confounded by sexual behaviors that transmit both HIV and human papillomavirus. Head and neck tumor incidence may also be increased, an important concern since these tumors are among the most common in India. Based on limited evidence, the increase is at buccal/palatal sites, which are associated with tobacco and betel nut chewing rather than human papillomavirus. Conclusion With improving care of HIV and better management of infections, especially tuberculosis, the longer survival of PHA in India will likely increase the importance of cancer as a clinical problem in India. With the population's geographic and social diversity, India presents unique research opportunities that can be embedded in programs targeting HIV/AIDS and other public health priorities.

Mass transfer properties (permeability and mass diffusivity) of four australian hardwood species

Characterization of mass transfer properties was achieved in the longitudinal, radial, and tangential directions for four Australian hardwood species: spotted gum, blackbutt, jarrah, and messmate. Measurement of mass transfer properties for these species was necessary to complement current vacuum drying modeling research. Water-vapour diffusivity was determined in steady state using a specific vapometer. Permeability was determined using a specialized device developed to measure over a wide range of permeability values. Permeability values of some species and material directions were extremely low and undetectable by the mass flow meter device. Hence, a custom system based on volume evolution was conceived to determine very low, previously unpublished, wood permeability values. Mass diffusivity and permeability were lowest for spotted gum and highest for messmate. Except for messmate in the radial direction, the four species measured were less permeable in all directions than the lowest published figures, demonstrating the high impermeability of Australian hardwoods and partly accounting for their relatively slow drying rates. Permeability, water-vapour diffusivity, and associated anisotropic ratio data obtained for messmate were extreme or did not follow typical trends and is consequently the most difficult of the four woods to dry in terms of collapse and checking degradation. © The State of Queensland, Department of Agriculture, Fisheries and Forestry, 2012.

Comparison of two methods to assess malnutrition in community-dwelling people with Parkinson's disease

Nutritional status in people with Parkinson’s disease (PD) has previously been assessed in a number of ways including BMI, % weight loss and the Mini-Nutritional Assessment(MNA). The symptoms of the disease and the side effects of medication used to manage them result in a number of nutrition impact symptoms that can negatively influence intake. These include chewing and swallowing difficulties, lack of appetite, nausea, and taste and smell changes, among others. Community-dwelling people with PD, aged >18 years, were recruited (n=97, 61 M, 36 F). The Patient-Generated Subjective Global Assessment(PG-SGA) and (MNA) were used to assess nutritional status. Weight, height, mid-arm circumference(MAC) and calf circumference were measured. Based on SGA, 16(16.5%) were moderately malnourished (SGA B) while none were severely malnourished (SGA C). The MNA identified 2(2.0%) as malnourished and 22(22.7%) as at risk of malnutrition. Mean MNA scores were different between the three groups,F(2,37)=7.30,p<.05 but not different between SGA B (21.0(2.9)) and MNA at risk (21.8(1.4)) participants. MAC and calf circumference were also different between the three groups,F(2,37)=5.51,p<.05 and F(2,37)=15.33,p<.05 but not between the SGA B (26.2(4.2), 33.3(2.8)) and MNA at risk (28.4(5.6), 36.4(4.7)) participants. The MNA results are similar to other PD studies using MNA where prevalence of malnutrition was between 0-2% with 20-33% at risk of malnutrition. In this population, the PG-SGA may be more sensitive to assessing malnutrition where nutrition impact symptoms influence intake. With society’s increasing body size, it might also be more appropriate as it does not rely on MAC and calf circumference measures.