24 research outputs found
Smoking prevalence, knowledge and attitudes among medical students in Karachi, Pakistan
A survey of smoking prevalence and attitudes was made among medical students randomly selected from classes at the Aga Khan University, Karachi, Pakistan. Of 271 respondents, 14.4% were current smokers (22.0% male and 3.8% females) and 3.3% ex-smokers. A majority of students recognized the dangers associated with active as well as passive smoking although only 55% of current smokers planned to quit in the near future. Most smokers (96%) believed that they as well as other health professionals needed training on smoking cessation and 95% of all students believed that doctors should play a role model in smoking cessation by not smoking themselves. Specific training and counselling should be a part of the required curriculum at medical schools
Simple and effective bacterial-based intratumoral cancer immunotherapy
Background
We describe intratumoral injection of a slow-release emulsion of killed mycobacteria (complete Freund’s adjuvant (CFA)) in three preclinical species and in human cancer patients.
Methods
Efficacy and safety were tested in mammary tumors in mice, in mastocytomas in mice and dogs, and in equine melanomas. In mice, survival, tumor growth, and tumor infiltration by six immune cell subsets (by flow cytometry) were investigated and analyzed using Cox proportional hazards, a random slopes model, and a full factorial model, respectively. Tumor growth and histology were investigated in dogs and horses, as well as survival and tumor immunohistochemistry in dogs. Tumor biopsies were taken from human cancer patients on day 5 (all patients) and day 28 (some patients) of treatment and analyzed by histology. CT scans are provided from one patient.
Results
Significantly extended survival was observed in mouse P815 and 4T1 tumor models. Complete tumor regressions were observed in all three non-human species (6/186 (3%) of mouse mastocytomas; 3/14 (21%) of canine mastocytomas and 2/11 (18%) of equine melanomas). Evidence of systemic immune responses (regression of non-injected metastases) was also observed. Analysis of immune cells infiltrating mastocytoma tumors in mice showed that early neutrophil infiltration was predictive of treatment benefit. Analysis of the site of mastocytoma regression in dogs weeks or months after treatment demonstrated increased B and T cell infiltrates. Thus, activation of the innate immune system alone may be sufficient for regression of some injected tumors, followed by activation of the acquired immune system which can mediate regression of non-injected metastases. Finally, we report on the use of CFA in 12 human cancer patients. Treatment was well tolerated. CT scans showing tumor regression in a patient with late-stage renal cancer are provided.
Conclusion
Our data demonstrate that intratumoral injection of CFA has major antitumor effects in a proportion of treated animals and is safe for use in human cancer patients. Further trials in human cancer patients are therefore warranted. Our novel treatment provides a simple and inexpensive cancer immunotherapy, immediately applicable to a wide range of solid tumors, and is suitable to patients in developing countries and advanced care settings.g Canberra trial: Canberra Hospital Private Practice Fund, Janice and
Ron Parker Fund. Mouse preclinical studies: Lea Chapuis Memorial Fund. Canine preclinical studies: The John and Mary Kibble Trust (grants CT22492, CT21335) and the William Peter Richards Bequest for research into veterinary pathology. CSEC, ERA, and AAA was supported by Australian Government Research Training Program Stipend Scholarships. CSEC and K-MS were supported by Max Lindemann Memorial Foundation, Miam
Novel sulfonated and fluorinated PEEK membranes for CO2 separation
Polymeric membranes containing sulfonated and fluorinated poly (ether ether ketone) were prepared by solution casting method. The monomers were pre-sulfonated before the polymerization to avoid the side effects of polymer post-sulfonation, like low degree of sulfonation and poor mechanical and thermal properties. The degree of sulfonation was varied from 20% to 40% to study its influence on the membrane performance. Pure and mixed gas permeation experiments were performed to evaluate the potential of this novel polymer in separation of CO2 from mixtures containing CH4 and N-2. Increasing degree of sulfonation improved the CO2 permeability and selectivity for both gas pairs. The incorporation of fluorinated groups further enhanced the performance of membranes by simultaneous increase in gas permeability and selectivity. Diffusion and solubility measurements were also performed in order to get further insight into the role of sulfonic and fluorinated groups in membrane performance. The comparison of results with literature revealed the promising characteristics of the polymer in industrially relevant gas separations. (C) 2016 Elsevier B.V. All rights reserved
Tuning the gas separation performance of fluorinated and sulfonated PEEK membranes by incorporation of zeolite 4A
Mixed matrix membranes (MMMs) containing fluorinated-sulfonated poly(ether ether ketone) (F-SPEEK) and zeolite 4A filler, were prepared by solution casting. F-SPEEK with a fixed degree of sulfonation (40%) was used for membrane synthesis. The SEM pictures showed good interfacial adhesion between filler particles and polymer, which was also confirmed by the increase in glass transition temperature of MMMs with increase in filler particles. Pure and mixed gas permeation experiments were carried out to investigate the potential of this membrane material. The results revealed that addition of zeolite 4A fillers enhanced both permeability and selectivity owing to the intrinsic nature of polymer and modified membrane morphology due to filler. The highest permeability obtained for CO2 at 30% filler loading was 49.2 Barrer, while highest selectivities obtained for CO2/CH4 and CO2/N-2 were 55 and 58 compared to 47 and 51 for the unfilled polymer, respectively. Intrinsic CO2 solubility of F-SPEEK was observed to be decreased from 10.7 to 1.9 (10(-2)) cm(3) (STP)/cm(3) cmHg with the addition of Zeolite 4A. (C) 2017 Wiley Periodicals, Inc
Onion Peel Ethylacetate Fraction and Its Derived Constituent Quercetin 4′-O-β-D Glucopyranoside Attenuates Quorum Sensing Regulated Virulence and Biofilm Formation
The resistance and pathogenesis of bacteria could be related to their ability to sense and respond to population density, termed quorum sensing (QS). Inhibition of the QS system is considered as a novel strategy for the development of antipathogenic agents, especially for combating drug-resistant bacterial infections. In the present study, the anti-QS activity of Onion peel ethylacetate fraction (ONE) was tested against Chromobacterium violaceum CV12472 and Pseudomonas aeruginosa PAO1. ONE inhibit the QS-mediated virulence factors production such as violacein in C. violaceum and elastase, pyocyanin in P. aeruginosa. Further, the treatment with sub-MICs of ONE significantly inhibited the QS-mediated biofilm formation, EPS (Extracellular polymeric substances) production and swarming motility. Further, quercetin 4′-O-β-D glucopyranoside (QGP) was isolated from ONE and its anti-QS potential was confirmed after observing significant inhibition of QS-controlled virulence factors such as violacein, elastase, pyocyanin and biofilm formation in test pathogens. Molecular docking analysis predicted that QGP should be able to bind at the active sites of Vfr and LasR, and if so blocks the entry of active sites in Vfr and LasR
Separation of Carbon Dioxide from Nitrogen or Methane by Supported Ionic Liquid Membranes (SILMs): Influence of the Cation Charge of the Ionic Liquid
Supported
ionic liquid membranes (SILMs) are promising tools for the separation
of carbon dioxide from other gases. In this paper, new imidazolium,
pyrrolidinium, piperidinium, and morpholinium ionic liquids with a
triethylene glycol side chain and tosylate anions, as well as their
symmetrical dicationic analogues, have been synthesized and incorporated
into SILMs. The selectivities for CO<sub>2</sub>/N<sub>2</sub> and
CO<sub>2</sub>/CH<sub>4</sub> separations have been measured. The
selectivities exhibited by the dicationic ionic liquids are up to
two times higher than the values of the corresponding monocationic
ionic liquids. Quantum chemical calculations have been used to investigate
the difference in the interaction of carbon dioxide with monocationic
and dicationic ionic liquids. The reason for the increased gas separation
selectivity of the dicationic ionic liquids is two-fold: (1) a decrease
in permeance of nitrogen and methane through the ionic liquid layer,
presumably due to their less favorable interactions with the gases,
while the permeance of carbon dioxide is reduced much less; (2) an
increase in the number of interaction sites for the interactions with
the quadrupolar carbon dioxide molecules in the dicationic ionic liquids,
compared to the monocationic analogues
Highly Selective Separation of Carbon Dioxide from Nitrogen and Methane by Nitrile/Glycol-Difunctionalized Ionic Liquids in Supported Ionic Liquid Membranes (SILMs)
Novel
difunctionalized ionic liquids (ILs) containing a triethylene
glycol monomethyl ether chain and a nitrile group on a pyrrolidinium
or imidazolium cation have been synthesized and incorporated into
supported ionic liquid membranes (SILMs). These ILs exhibit ca. 2.3
times higher CO<sub>2</sub>/N<sub>2</sub> and CO<sub>2</sub>/CH<sub>4</sub> gas separation selectivities than analogous ILs functionalized
only with a glycol chain. Although the glycol moiety ensures room
temperature liquidity of the pyrrolidinium and imidazolium ILs, the
two classes of ILs benefit from the presence of a nitrile group in
different ways. The difunctionalized pyrrolidinium ILs exhibit an
increase in CO<sub>2</sub> permeance, whereas the permeances of the
contaminant gases rise negligibly, resulting in high gas separation
selectivities. In the imidazolium ILs, the presence of a nitrile group
does not always increase the CO<sub>2</sub> permeance nor does it
increase the CO<sub>2</sub> solubility, as showed in situ by the ATR-FTIR
spectroscopic method. High selectivity of these ILs is caused by the
considerably reduced permeances of N<sub>2</sub> and CH<sub>4</sub>, most likely due to the ability of the −CN group to reject
the nonpolar contaminant gases. Apart from the CO<sub>2</sub> solubility,
IL–CO<sub>2</sub> interactions and IL swelling were studied
with the in situ ATR-FTIR spectroscopy. Different strengths of the
IL–CO<sub>2</sub> interactions were found to be the major difference
between the two classes of ILs. The difunctionalized ILs interacted
stronger with CO<sub>2</sub> than the glycol-functionalized ILs, as
manifested in the smaller bandwidths of the bending mode band of CO<sub>2</sub> for the latter