By T. Phil. Barnard College.
Materials Required : Stock solution of Zn (5000 mcg ml–1) : Dissolve Zn metal (Anala-R-Grade) 2 buy 100mcg proventil with mastercard. Spray the solution by adopting the standard procedure and read off the concentration of zinc from a calibration curve prepared with solution containing 0 purchase proventil 100 mcg without prescription. Heat purchase proventil 100 mcg on line, gently at first, then more strongly until all carbon is removed and a white ash is obtained. Allow to cool and add 5 ml of a mixture of nitric acid and hydrochloric acid and evaporate to dryness on a water-bath. Add 3 ml of hydrochloric acid, warm to dissolve and add sufficient water to produce 25 ml. Place in each of three similar graduated flasks equal volumes of the solution of the substance pre- pared as above. Add to all but one of these flasks a measured quantity of the specified standard solution of palladium to produce a series of solutions containing increases amounts of Pd. After calibrating the instrument as stated above, introduce each solution into the generator 3 times and record the steady reading at 248 nm. Plot the mean of the readings against concentration on a graph the axes of which intersect at zero added Pd and zero reading. Extrapolate the straight line joining the points until it meets the extrapolated concentration axis. The distance between this point and the intersection of the axes represents the concentration of Pd present in the prepared solution of carbenicillin sodium. How would you explain the mathematical expression derived from the total amount of light absorbed? How do the following three types of interferences affect the atomic absorption spectroscopic methods : (a) Spectral interferences, (b) Chemical interferences, and (c) Ionisation interferences. Discuss the assay of the following medicinal compounds in an elaborated manner : (i) Total Zn in insulin Zn suspension, (ii) Pd in carbenicillin sodium, (iii) Ag in cisplatin, (iv) Fe in Ascorbic acid, (v) Pb in Oxprenolol hydrochloride, and (vi) Ni in Prazosin hydrochloride. Sargent, ‘Atomic Absorption and Fluorescence Spectroscopy, New York, Academic Press, 1974. The normal-feasible separations which can thus be achieved are found to be rather easy, fast, convenient and effective resonably. Invariably such separations may be performed by shaking the two liquids in a separatory funnel for a few minutes ; and may be extended either to large quantities of pharmaceutical substances or trace levels. In the case of pharmaceutical chemicals that are mostly ‘organic solutes’, the liquid-liquid extraction system may very often make use of two immiscible organic solvents (e. On the contrary, the ‘inorganic solutes’ normally encountered are in- variably in aqueous solutions ; therefore, it has become absolutely necessary to produce such neutral sub- stances out of them, for instance ion-association complexes and metal-chelates (using organic-ligands) that may be extracted into an appropriate organic solvent. In short, liquid-liquid extraction has been employed predominantly and effectively not only for the pre-concentration and isolation of a ‘single’ chemical entity just before its actual estimation, but also for the extraction of classes of organic compounds or groups of metals, just prior to their usual estimation either by chromatographic techniques or by atomic-absorption methods. Now, if a third substance is made to dissolve in a two-phase mixture of the solvents (i. Therefore, under these prevailing experimental parameters the ratio of the mole fractions of the solute in the two respective immiscible phases (‘a’ and ‘b’) is found to be a constant which is absolutely independent of the quantity of solute present. It is termed as the Nernst Distribution Law or the Partition Law and may be expressed as follows : A a Concentration of solute in solvent ‘a’ Kp = =... The constant (Kp) is also known as the distribution coefficient or the partition coefficient. However, the Partition Law offers the following two limitations, namely : (a) It is not thermodynamically rigorous i. In other words, it is solely applicable to very dilute solutions in which case the ratio of the activities almost approaches unity, and (b) It does not hold good when the distributing substances encounters association or distribution in either phases (i. Consequently, a more rigorous treatment particularly specifies Kp as the ratio of the activities of the substance (A) in the two solvents instead of their concentrations. Hence, for dilute solutions, at a specified constant pressure and temperature, the mole fraction of a solute is directly proportional to its concentration in molarity or mass per unit volume ; which implies that these may be employed instead of mole-fraction in Eq. Thus, the Partition Coefficient Kp is also given by the following expression : S1 Kp =... Adequate precaution and care must be exercised in determining partition coefficients based on the solubility data as S1 is not the solubility of substance ‘A’ in pure Solvent ‘a’, but rather the solubility in Solvent ‘a’ saturated with Solvent ‘b’. Example : In order to determine the exact partition coefficient of substance ‘A’ between water and ethyl acetate, the appropriate solubilities would be those of the substance ‘A’ in 3. Solvent Pair tion Phases of Azeotrope of Azeotrope of Solvents (%) (°C) (°C) Upper Lower 1. Therefore, a number of procedures have been adopted to avoid ‘error due to the volume change’ incurred thereby, namely : (i) Measure the volume of the phase employed for the analysis and incorporate this volume in the calculations, (ii) Separate the phase quantitatively and subsequently dilute to a known volume, (iii) Separate the phase quantitatively and make use of the entire volume in the remaining steps of the ongoing analysis, and (iv) Carry a marker substance through the extraction to automatically compensate for volume changes. However, the latter procedure finds its abundant use in chromatographic methods of analysis. Let us assume that ‘x’ moles of solute present initially in a volume V2 of Solvent ‘b’. Now, this particular sample undergoes extraction with a volume V1 of Solvent ‘a’ and subsequently ‘y’ moles of com- pound are left in V2 at equilibrium. Hence, the fraction left unextracted after ‘n’ extraction may be given by the following expression : − n F V1 I fn = G Kp + 1J...... Therefore, it is absolutely necessary to take this into consideration while selecting an appropriate extraction-system. Thus, the effect of temperature on the partition coefficient may be estimated conveniently from its effect on the solubilities of the substance in the two respective solvents.
Interestingly buy generic proventil 100 mcg, the promastigote treatment with ill effects on the microtubules or the organisms  effective proventil 100 mcg. Gene 363 proventil 100 mcg, 85–96 (1998) Leishmania major: cell type dependent distribution of a 43kDa antigen related to 31 Freitas-Junior, L. Cytoskeleton 42, 48–59 (2002) Biogenesis of Leishmania-harbouring parasitophorous vacuoles following 46 Palazzo, A. In the case of protozoan species that are causative agents of important human diseases such as Leishmaniasis, an exogenous supply of polyamines supports parasite proliferation. A significant reduction of promastigotes and axenic amastigotes growth was observed in the presence of increasing concentrations of the drugs, although the mechanisms leading to the parasite growth arrest seems to be different. Indeed, by using a number of biochemical approaches to analyse the alterations that occurred during early stages of parasite-drug interaction (i. The drug inhibitory effect on amastigotes growth and the absence of propidium iodide labelling may suggest that the compounds are acting as cytostatic substances. Although, the mechanisms of action of these compounds have yet to be elucidated, the above data show for the first time that polyamine derivatives may act differentially on the Leishmania parasite stages. Further chemical modifications are needed to make the polyamine derivatives as well as other analogues able to target the amastigote stage of the parasite. In the case of protozoan species that are causative agents of important human diseases such as Leishmaniasis, an exogenous supply of polyamines supports parasite proliferation. A signiﬁcant reduction of promastigotes and axenic amastigotes growth was observed in the presence of increasing concentrations of the drugs, although the mechanisms leading to the parasite growth arrest seems to be different. Indeed, by using a number of biochemical approaches to analyse the alterations that occurred during early stages of parasite-drug interaction (i. The drug inhibitory effect on amastigotes growth and the absence of propidium iodide labelling may suggest that the compounds are acting as cytostatic substances. Although, the mechanisms of action of these compounds have yet to be elucidated, the above data show for the ﬁrst time that polyamine derivatives may act differentially on the Leishmania parasite stages. Further chemical modiﬁcations are needed to make the polyamine derivatives as well as other analogues able to target the amastigote stage of the parasite. Introduction donovani infantum, especially affects children and South American visceral leishmaniasis caused by Leishmania In humans, parasites from the Leishmania donovani donovani chagasi is a disease of both adults and children. Mediterranean Kala-azar, caused by Leishmania antimonials such as sodium stibogluconate (Pentostan), N-methylglucamine (Glucantime), amphotericin B or penta- midine (Murry, 2001). Address: Laboratorio de Bioquımica, Faculdade´ ´ ´ duration of therapy, causing adverse reactions and resistance de Farmacia da Universidade do Porto, Rua Anibal Cunha, 164, 4050-047 Porto, Portugal. However, analyses of the drug-induced alterations agents acting on parasite development is still warranted. In trypanosomatid protozoa, polyamines have an additional role participating in the endogenous redox equilibrium 2. Materials and methods through the compound (N1, N8-bis (glutathionyl) spermi- dine), named trypanothione T(S)2, which is maintained in 2. The parasites (10 /ml) in the logarithmic phase that selective interference with the parasitic polyamine (2 days of culture) were incubated with a serial range of metabolism will lead to an alteration of natural defence concentrations of each drug for 5 days at 28 8C. The percentage of growth inhibition amine analogues, able to mimic the natural polyamines in was calculated as (1-growth rate of the experimental their self-regulatory role, but unable to act as substitutes for culture/growth rate of the control culture)! The growth of parasites was determined by the same After several washes, the parasites were permeabilised with methods described above. Parasites were then To monitor parasite death, short incubation periods were incubated with a rabbit immune serum to a L. Flow cytometric analysis of external in Vectashield (Vector Laboratories) and analysed with a phosphatidylserine exposure ﬂuorescent microscope (Axioskop-Carl Zeiss, Germany) at 1000! Statistical analysis amastigotes treated and untreated with 10 mM of either of the three drugs during 24 h, was determined using The data were analysed using the Student’s t-test. The polyamine derivative drugs control the growth of Leishmania infantum parasites Treatment of L. It can be seen that at R12 mM all the three drugs completely blocked both promastigote and amastigote multiplication. Promastigote (closed square) and amastigote (open square) forms were incubated with a concentration range of 0. Percentages of promastigote and amastigote fragmentation in Leishmania infantum promastigotes growth inhibition were determined after 5 days by counting using a Newbauer chamber under light microscopy. Each point represents the mean In order to determine whether the observed effect was of two replicates G standard deviation. The data shown is representative of due to a leishmanicidal activity and to establish the type at least three independent experiments. The growth rate of the promastigote and amastigote parasite forms without drug treatment was 24 and 100 times related to the initial concentration, respectively. However, examination of a number of slides showed slightly different patterns of labelling. Quantiﬁcation of phosphatidylserine externalisation in gotes showed no signiﬁcant increase of Annexin-V positive Leishmania infantum promastigotes and amastigotes cells (Fig. This is likely due the translocation of phosphatidylserine from the inner side to the absence of apoptosis induction since amastigotes to the outer layer of the plasma membrane. Annexin V, 2C treated with 4 mM staurosporine, a drug known to induce aCa dependent phospholipid binding protein with apoptosis-like death in Leishmania showed around 80% afﬁnity for phosphatidylserine, is routinely used in a Annexin-V positive cells (Fig. Flow cytometry analysis of phosphatidylserine exposure to Leismania infantum after polyamine derivative compound treatment. Discussion In contrast to the promastigotes, we were unable to detect any modiﬁcation of amastiogotes mitochondrial membrane The polyamine family including putrescine, spermidine potential after 12 h, (Fig. Surprisingly, although a growth are known to be essential factors for the growth of the inhibition could be clearly demonstrated in the case of parasites in their host and that cancer cells and Leishmania drug treated axenic amastigotes, we were unable to parasites share at least one common feature, that is their observe any of the apoptosis-like features occurring in mutual capacity for rapid cell division, we attempted to the drug treated promastigote forms.
A year later generic proventil 100mcg mastercard, a study of 111 amoxicillin samples collected in four Arab countries found that 56 percent failed U buy 100mcg proventil. It is diff- cult order 100mcg proventil otc, however, to draw frm conclusions about substandard drug production from these studies. Antibiotics degrade quickly in warm climates; it is hard to distinguish substandard manufacture from poor storage and handling. When researchers test only authorized products, they bias their sample against the unregistered products used by the poorest (Seear et al. Some convenience samples have compared the quality of approved and un- approved products. Between 2008 and 2012, Bate and colleagues collected samples of 2,652 anti-infective drugs from around the world: 11 African cities, 3 Indian cities, Bangkok, Beijing, Istanbul, Moscow, and São Paulo. The report mentions that the failure rates were higher among samples from Africa than among samples from middle- income nations (Bate et al. Acute malaria episodes come on quickly and often; antimalarials are bought on short notice from the most 3 Including, but not limited to, amoxicillin, ampicillin, chloroquine, rifampicin, and co-trimoxazole. For these reasons, they are often the target of criminals and unscrupulous manufacturers. Investigators found unregistered medicines least often at the central distribution level (see Figure 3-4). A recent review paper includes some higher estimates of poor-quality antimalarial drugs (Nayyar et al. The review included 28 published and unpublished studies, mostly (n = 22) from convenience samples, but also 7 that included some type of randomized design (Nayyar et al. Of the 497 samples that failed chemical testing, 34 percent had no active ingredient; 4 percent had low active ingredient. In a subset of 919 samples with intact packaging and a verifed, genuine packaging sample for comparison, 46 percent failed packaging analysis (Nayyar et al. Investigators classifed all drugs failing packaging analysis as falsifed, as well as those substandard drugs that contained no active ingredient or an ingredient not listed on the label (Nayyar et al. Nayyar and colleagues used the same criteria to categorize samples from sub-Saharan African countries (Nayyar et al. Forty-fve percent of the studies reported active ingredient test results, fnding that 121 (15 percent) had low active ingredient and 3 percent had excessive active ingre- dient (Nayyar et al. Only one study reported packaging analysis, and it found 36 percent failure (Nayyar et al. Nayyar and colleagues had fewer African samples (n = 389) from which to calculate the percentage of falsifed drugs; they found 20 percent falsifed (see Table 3-7) (Nayyar et al. A consistent problem with all convenience surveys of drug quality is that they tend to sample heavily from the formal market: licensed phar- macies and dispensaries. Results of these studies will likely underestimate the burden of falsifed and substandard drugs in places where much of the population buys essential medicines in unregulated bazaars. Sampling from these vendors is diffcult, but a convenience sample of informal and private medicine sellers in Guyana and Surinam found 58 percent of the antimalarial samples from Guyana and all the samples from Surinam to be falsifed or substandard (Evans et al. In a Burkina Faso study, Tipke and colleagues compared antimalarial drug quality in licit and illicit vendors. They found that 90 percent of samples from street vendors and open markets were substandard, and only 10 percent of samples from legal vendors were substandard (Tipke et al. This section presents the results of a few population-based random surveys of drug quality. Kaur and colleagues analyzed antimalarial quality in drugs drawn from a systematic, random sample of a range of Tanzanian retail outlets, including drug stores, general stores, street hawkers, and medicine kiosks Copyright © National Academy of Sciences. Investigators stratifed districts according to their par- ticipation in a national bed net program, chose districts at random from among the strata, and then surveyed 30 percent of wards in each study district (Kaur et al. They divided wards into major and nonmajor trading centers and drew half the samples from each type of market (Kaur et al. Between May and September 2005, investigators collected 1,080 samples from 2,474 vendors, one from each store that had them in stock on the day of the study visit (Kaur et al. After excluding 166 expired samples and 32 with no labeled expiry date, investigators had 882 samples, from which they systematically chose 301 for chemical analysis (Kaur et al. Taylor and colleagues collected 581 drugs from 35 randomly selected registered pharmacies in urban Nigeria (Taylor et al. They found 42 percent of antimalarials, 41 percent of antibacterials, and 54 percent of antituberculosis drugs outside of British Pharmacopoeia limits (Taylor et al. A stratifed random sample of medicine shops and licensed pharmacies in Laos found 90 percent of artesunate samples failed quality testing (Sengaloundeth et al. Researchers in southeast Nigeria attempted to include unlicensed private medicine dealers in their sample of antimalarial drug quality (Onwujekwe et al. They collected samples of a range of antimalari- als from patent medicine dealers, pharmacies, public and private hospitals, and primary health care centers (Onwujekwe et al. Pharmacopeia specifcations, by either not containing the active ingredient listed or containing it in low doses (Onwujekwe et al. Among the failed samples, 60 percent came from low-level shops, mostly the patent-medicine shops (Onwujekwe et al. Though most epidemiologically rigorous research on drug quality has tested antimicrobial drugs, there is some information about other essential medicines. In a 2012 study, Stanton and colleagues prepared an exhaus- tive sampling frame of formal and informal drug sellers in three districts in Ghana (Stanton et al.
These were based on the hypothesis that drug use stems from direct or indirect social influences from peers and the media buy proventil 100 mcg lowest price. There is little evidence of reduction in the use of illicit drugs as a result of these programmes buy proventil 100 mcg without prescription. Research cheap proventil 100 mcg overnight delivery, including the 2005 Cochrane review,11 has found that these high-quality school-based multifaceted programmes show a marked improvement in young people’s knowledge and skills, which can have a small impact on illicit drug use, and drug behaviour, most notably in delaying the onset of use. Programmes that change the environment of a classroom or school are thought to be more effective than those that try to change individual behaviour. Stronger effects were found in boys who were identified as aggressive and disruptive at a young age. The long-term effects of this intervention appear to compare well with the best school- based programmes aimed specifically at drug prevention. Research has demonstrated that factors that predict development of a drug problem are also predictive of school failure, social isolation, aggression and other problems. It should be noted that, despite this limited evidence base, large amounts of pupil and staff time are invested in these types of intervention. This guidance also states that all schools should have a drug policy that sets out the school’s role in relation to all drug matters, which includes the content and organisation of any drug education programme. Box 7 – Combating the psychological attractiveness and social acceptance of drugs As identified in Chapter 4, heavy exposure to substance use in popular media may influence drug use. Universal interventions aimed at reducing the use of drugs may need to be rethought by policy makers. These lessons take place for finite number of hours a year, with information on health behaviours such as drug use often competing with other modules. Over the same time period, the average person is likely to be exposed to a larger number of hours of drug-promoting references in film, television, popular music, video games and the internet. This large disparity between the exposure to drugs in popular media, and interventions to reduce the use of illicit drug use, may result in the efficacy of interventions to reduce the use of drugs being diluted by the widespread exposure to drug imagery. Appendix 7 explores current and possible policy options to counter the psychological attractiveness and social acceptance of drug use within popular media. The Home Office’s Blueprint drugs education programme,19 which ran from 2003 to 2007, was the largest drugs education programme that has ever been run in Britain. The programme provided drug education lessons to school children aged 11 and 12 years, across 23 different schools in England. It aimed to equip pupils with the knowledge and experiences necessary to make informed choices about drug use. Those who had never taken drugs were more likely to say that lessons had helped them to avoid drugs, and to think about what to do if they were offered drugs. The guidance also advises that drug testing should be placed within the wider context of educating children about the risks, effects and consequences of drug use. Since the publication of this guidance in 2004, the uptake of drug testing in schools has been limited. Research has demonstrated that drug use does not differ between schools with and without drug testing. In 2006, the Cochrane Collaboration published a systematic review of interventions for the prevention of drug use delivered to young people in non-school settings. The lack of research in this area meant the authors were unable to carry out a meta- analysis and pool results across similar interventions. It was suggested that further high-quality research was needed before any conclusions could be made on the efficacy of non-school-based prevention strategies. Significant effects on reducing drug use were detected for individual family interventions. Education and skills training were found to have little effect on reducing drug use. Mass media and social marketing approaches Mass media campaigns are commonly used as part of universal strategies to reduce drug use. Friendly confidential drugs advice) is the most recent example of a mass media prevention initiative. This was established by the Department of Health and the Home Office in 2003 and included an online information source. An analysis of 13 review papers concluded that the use of mass media alone improved awareness of drug harms in some cases, but overall was not effective in reducing illicit drug use. Using social marketing to enhance mass media approaches may be a useful way of increasing the efficacy of mass media campaigns. Social marketing differs from commercial marketing, in that it tries to sell ‘ideas’ to consumers, as opposed to products. Social marketing seeks to influence social behaviours and benefit the target audience. Using social marketing to deliver health messages presents a developing area in reducing the uptake of drugs. An evaluation of social marketing to reduce alcohol and cannabis use found a significant effect in terms of lifetime cannabis use. Selective and indicated prevention strategies overcome this by targeting specific groups at heightened risk of using drugs. Research has demonstrated that these groups commonly include the homeless, those looked after by local authorities or in foster care, sex workers, truants and those excluded from school, young offenders, children from substance-using families, and young people with conduct or depressive disorders (see Section 4. There is a limited amount of high-quality research in this area, but the evidence that is available suggests these interventions have some effect at reducing drug use among vulnerable groups. The age at which interventions take place among vulnerable young people appears to have a significant impact on illicit drug use. The 2005 review discussed above identified the age range 11 to 13 years as a crucial period for interventions. For vulnerable children at high risk, interventions in non-school settings may need to be explored, as these children may have higher levels of school truancy.