Does the effect of herbicide pulse exposure on aquatic plants depend on Kow or mode of action?

The highest concentrations of herbicides measured in flowing surface waters are often only present for short periods of time. These herbicide pulses can reach concentrations that would affect aquatic plants if present over a long time. The aim of this study was to assess the effect of a 3-h herbicide pulse relative to the effects of long-term (4 and 7 days) exposure of six herbicides with different sites of action and different K(ow) on the growth of the floating macrophyte Lemna minor. The herbicides were the two photosynthetic inhibitors: diquat and terbuthylazine, the inhibitors of acetolactate syntase (ALS), imazamox and metsulfuron-methyl and the microtubule assembly inhibitors propyzamide and pendimethalin. The log K(ow) ranged from -4.6 to 5.2. For imazamox, metsulfuron-methyl, propyzamide and pendimethalin a 3-h pulse induced the effect on area-specific growth as did a 4-day exposure at an approximate 10-fold higher concentration. For diquat and terbuthylazine a concentration closer to a factor of 100 or more was needed for a 3-h pulse to induce an effect similar to that of a 4-day exposure. For diquat, the low pulse-effect was most likely due to a slow uptake of the hydrophilic ion (log K(ow) = -4.6), as no effect was observed on chlorophyll fluorescence within 8 h after exposure. The chlorophyll fluorescence parameters are expected to respond quickly to a PSI inhibitor as diquat. For terbuthylazine, fluorescence measurements showed an effect on photosynthesis within 1h of exposure, and reached a minimum after 3 h. Recovery was fast, and initial fluorescence was restored within 24 h. Hence, the small pulse effect on area-specific growth was due to rapid recovery of photosynthesis. In contrast to terbuthylazine, the stop in area-specific growth observed for the ALS-and microtubule assembly inhibitors, took up to 4 days to recover from. Such a long recovery time after a pulse of only 3 h indicate that at realistic pulse exposures of up to a day or two, pulse-effects will approach the effects obtained in long-term studies. When investigating the effects of pulse exposures on aquatic plants, we should therefore focus more on non-photosynthetic inhibitors, which might not appear in pulses in as large concentrations as the PSII inhibitors investigated up till now, but whose effect, even in a shorter pulse, can be more damaging.     

A study of the effect of sulphinpyrazone (‘Antman’) on blood viscosity

Summary

A double-blind, placebo-controlled crossover study oj the effect of sulphinpyrazone on blood viscosity and its determinants (haematocrit, plasma fibrinogen and plasma viscosity) was carried out in 7 healthy male volunteers. Apart from a transient rise in fibrinogen (p<0.05) after 3 days of sulphinpyrazone treatment, no significant change in viscosity factors was seen over a 14-day period.     

A systematic review of the literature on ‘medication wastage’: an exploration of causative factors and effect of interventions

Introduction Reducing any wastage, including that of medications, is a paramount objective in promoting appropriate utilisation of finite resources. The objective was to systematically review the published literature, the possible causative factors associated with medication wastage and the effectiveness of any interventions to reduce wastage. Method A systematic review of studies published in English was identified from the following databases: Cumulative Index to Nursing and Allied Health Literature, Embase, Medline, PubMed, Science Citation Index and The Cochrane Library. Data extraction and critical appraisal was undertaken independently by two researchers. Results and discussion Title, abstract and full paper screening reduced the 14,157 studies to 42. A general definition of medication wastage was reported in one paper only. ‘Medication changed’, ‘patient death’, ‘resolution of patient’s condition’ and ‘expired medications’ were most commonly cited reasons for wastage. Only two studies were identified reporting wastage as a research outcome measure following intervention. Conclusion The systematic review has identified a limited literature on medication wastage with a lack of consistency of terms. There is a paucity of robust research focusing on the impact of healthcare interventions on outcomes around medication wastage.     

A test of the concept of ‘underlying depressive illness’ in the treatment of anxiety states

Summary

In order to test the validity of the concept of anxiety states masking an underlying depressive illness, patients clinically diagnosed as suffering from anxiety or tension states were treated on a random double-blind basis for 4 weeks with either a pure anxiolytic, lorazepam, or an anxiolytic / antidepressant preparation, fluphenazine with nortriptyline. Patients' self ratings were very similar to the physicians' ratings which showed that fluphenazine / nortriptyline was associated with significantly greater overall improvement (p<0.01), as well as significantly greater improvement in the group of symptoms specifically related to depression (p<0.05). These results suggest that a depressive element is present in an appreciable proportion of patients presenting with apparent anxiety states, and antidepressant as well as anxiolytic treatment is required.

Patients selected on the basis that they had improved satisfactorily at the end of the 4-weeks' treatment were followed up for a further 3 months without medication, and the relapse rate was 24%, irrespective of previous treatment. More of the patients treated with lorazepam had to be excluded from the follow-up because of failure to improve, and these probably represented the proportion (19%) of this population with an appreciable depressive element to their illness.     

Are drinking habits really changing? A cross-generational test of the ‘new’ phenomenon of ‘binge-drinking’

Aims: To investigate whether ‘binge-drinking’ is new by comparing the behaviour and attitudes of two generations at the same age and of one generation at different ages.

Methods: Fifty-six student/parent pairs completed questionnaires partially based on the Adolescent version of the Alcohol Expectancy Questionnaire (Brown, S.A., Christiansen, B.A., & Goldman, M.S. (1987). The alcohol expectancy questionnaire: An instrument for the assessment of adolescent and adult alcohol expectancies. Journal of Studies on Alcohol, 48, 483–491). Students’ reports of their behaviour and attitudes were compared to their parents’ memories of their behaviour and attitudes at 18. Parents’ memories were compared to their current behaviour and attitudes to explore possible lifespan effects. Data regarding the groups’ attachment to aspects of society were drawn on as a possible explanation of differences between generations.

Findings: Parents recalled consuming more alcohol more frequently, having more favourable attitudes towards alcohol and having fewer ties with their communities when they were 18 than their children. They drank less and had a less favourable attitude towards alcohol at the time of the research than in their youth.

Conclusions: Despite contrary ‘evidence’, it may be that today's young people are less prone to ‘binge-drinking’ than previous generations. Whilst it is recognized that data may be contaminated by parents’ ‘forgetting’, the study highlights the possibility that the ‘binge-drinking’ crisis is merely media hype, spurious, or both.     

A review of tinnitus symptoms beyond ‘ringing in the ears’: a call to action

Abstract

Background:

Tinnitus, often referred to as ‘ringing in the ears’, is highly prevalent. However, patients may also present with a number of other symptoms.     

The misuse of the ‘Gateway Theory’ in US policy on drug abuse control: A secondary analysis of the muddled deduction

Much research (mostly from general population surveys) suggests that people typically use alcohol, tobacco and then marijuana, so called ‘gateway drugs’, prior to any potential use of ‘hard drugs’ like cocaine powder, crack and heroin. Other research (mostly with surveys of special populations) indicates that hard-drug use is associated with numerous social problems such as crime, routine violence, and lower productivity. A muddled interpretation of these separate findings has been widely misused in support of the US drug abuse prevention policies to suggest that gateway drugs cause hard-drug use and its associated problems. This paper superimposes secondary analyses of data from the National Household Survey on Drug Abuse (NHSDA) and the Arrestee Drug Abuse Monitoring (ADAM) program. The findings indicate that (1) extremely few members of the general population become persistent daily hard-drug-using criminal offenders; and (2) an increasing percentage of daily hard-drug-using criminal offenders did not follow the gateway sequence of substance use progression. These results strongly suggest that the use of gateway drugs by youths is not the central cause of hard-drug use and its associated problems. Thus, fighting the use of gateway drugs by youths may not be a particularly appropriate approach to drug abuse prevention.     

A critical examination of the definition of ‘psychoactive effect’ in Australian drug legislation

As the number of new ‘psychoactive substances’ detected globally has risen exponentially, the policy response of assessing and prohibiting each new substance individually has become increasingly unworkable. In an attempt to disrupt the availability of new as-yet-unscheduled substances, Ireland (2010), Poland (2011), Romania (2012), New Zealand (2013), Australia (2015) and the United Kingdom (2016) have enacted generic or blanket ban legislation that prohibits all ‘psychoactive substances’ that are not already regulated or belong to exempt categories. How such generic legislation defines ‘psychoactive substance’ is therefore crucial. While there is a growing critical literature relating to blanket bans of ‘psychoactive substances’, the Australian legislation is yet to be described or critically analysed. In this commentary, we aim to draw the attention of local and international drug policy scholars to Australia’s newest legislative approach to ‘psychoactive substances’. Using the Australian experience as a case study, we first describe and trace the origins of this generic banning approach, especially focusing on how ‘psychoactive effect’ came to be defined. Then, we critically examine the assumptions underpinning this definition and the possibilities silenced by it, drawing on the work of poststructuralist and critical scholars. In doing so, we explore and raise a series of questions about how this legislation works to stabilise drugs, drug harms and drug effects, as well as addiction realities; how the category of ‘psychoactive substances’ is produced through this legislation; and some of the material-discursive effects which accompany this rendering of the ‘problem’. We offer this commentary not as a comprehensive discussion of each of these elements but rather as a starting-point to promote further discussion and debate within the drug policy field. To this end, we conclude with a suggested research agenda that may help guide such future work.     

The effect of mandatory generic substitution on the safety of alendronate and patients’ adherence

Abstract

Objective:

Generic medicines are often used in public hospitals. However, data on the quality of generic alendronate, its efficacy, side-effects and medication adherence in clinical practice is scarce. Therefore, this study aimed to compare the side-effects and medication adherence of generic (apo-alendronate) and proprietary alendronate (Fosamax).     

How persistent is the effect of smoking urges on cognitive performance?

Several studies have provided empirical support for S. T. Tiffany's (1990) hypothesis that drug urges interfere with cognitive performance. The authors examined the persistence of this effect. Results from an experiment involving 48 smokers and 46 nonsmokers, using a paradigm developed by R. A. Zwaan and T. P. Truitt (1998), suggest that the effect of smoking urges in cognitive performance dissipates over time. The implications of this finding for cognitive theories of drug urges and for future research on the effects of smoking urges are discussed.     

A placebo-controlled study of sertraline’s effect on cortisol response to the dexamethasone/corticotropin-releasing hormone test in healthy adults

Rationale  

The dexamethasone/corticotropin-releasing hormone (Dex/CRH) test is a neuroendocrine probe involving serial blood sampling of cortisol during a standardized pharmacological challenge without inducing psychological distress in humans. Some past studies in depressed patients have shown a “normalization” or decrease in cortisol response to the Dex/CRH test following successful treatment with an antidepressant. Studies in nondepressed healthy adult samples have also shown aberrant cortisol reactivity to be associated with depression risk factors. These findings prompted research into the use of the Dex/CRH test as a tool for developing antidepressant drugs.     

The bacterial genotoxicity test：issues to be considered in the performance of the test and their recent advances

The bacterial genotoxicity test is widely used as an initial screening to determing the genotoxic potential of chemicals for hazard identification.Firstly,I will state about technical issues in the performance of the test,which may largely affect the results of the mutagenicity of test compounds of lead to low concordance with the results between inter-and intra-laboratories.The second issue of my speech will be a brief review on bacterial tester strains that are highly sensitive to the mutagenicity of particular classes of mutagens.These strains are often used to efficiently explore environmental mutagens and to study the mechanisms of mutagenesis.Finally,I will present our recent study on the use of human S9 fractions in the genotoxicity tests to comprehensively evaluate the genotoxic effect to humans.In addition,genetically-engineered tester strains expressing human drug-metabolizing enzymes will be introduced.     

‘Surfing the Silk Road’: A study of users’ experiences

IntroductionThe online drug marketplace called ‘Silk Road’ has operated anonymously on the ‘Deep Web’ since 2011. It is accessible through computer encrypting software (Tor) and is supported by online transactions using peer to peer anonymous and untraceable crypto-currency (Bit Coins). The study aimed to describe user motives and realities of accessing, navigating and purchasing on the ‘Silk Road’ marketplace.MethodsSystematic online observations, monitoring of discussion threads on the site during four months of fieldwork and analysis of anonymous online interviews (n = 20) with a convenience sample of adult ‘Silk Road’ users was conducted.ResultsThe majority of participants were male, in professional employment or in tertiary education. Drug trajectories ranged from 18 months to 25 years, with favourite drugs including MDMA, 2C-B, mephedrone, nitrous oxide, ketamine, cannabis and cocaine. Few reported prior experience of online drug sourcing. Reasons for utilizing ‘Silk Road’ included curiosity, concerns for street drug quality and personal safety, variety of products, anonymous transactioning, and ease of product delivery. Vendor selection appeared to be based on trust, speed of transaction, stealth modes and quality of product. Forums on the site provided user advice, trip reports, product and transaction reviews. Some users reported solitary drug use for psychonautic and introspective purposes. A minority reported customs seizures, and in general a displacement away from traditional drug sourcing (street and closed markets) was described. Several reported intentions to commence vending on the site.ConclusionThe study provides an insight into ‘Silk Road’ purchasing motives and processes, the interplay between traditional and ‘Silk Road’ drug markets, the ‘Silk Road’ online community and its communication networks.     

‘Following the money’: The political economy of gambling research

Although clear relationships have been identified between dependent drug use and crime, the relationship is less evident in young offenders, particularly for less physically dependent users. This study investigated a sample of young drug-using offenders (aged 18–24; n = 36) accessing drug treatment through the criminal justice system in Birmingham, UK, using structured interviews for the collection of both qualitative and quantitative data. It identified high levels of heroin dependence, with frequency of use linked to both acquisitive crime and willingness to engage in treatment. The relationship between crack cocaine use and offending was less clear with more client ambivalence regarding desire to stop using the drug. Whilst most praised their treatment, and their workers, substitute prescribing was less positively endorsed. The study offers some support for diverting young dependent opiate users from criminal justice services into drug treatment, but presents a less positive prognosis for primary stimulant users.     

The significance ofβ-adrenoceptor down regulation in the desipramine action in the forced swimming test

Summary The present studies were undertaken to clarify whether central-adrenoceptor down regulation is responsible for the greater effect of chronic treatment with desipramine (DMI) compared with acute treatment in the forced swimming test in rats. Repetitive administration of DMI activated the rat behaviour pattern and consequently reduced the duration of immobility. The degree of activation depended on the length of treatment, i.e. no effect when given in a single dose, moderate effect when given subchronically (3 doses) and marked activation after chronic (31 doses) treatment. Chronic treatment with DMI also produced a decrease in³H-dihydroalprenolol (³H-DHA) binding site in the cerebral cortex. Acute stimulation of brain-adrenoceptors by intracerebroventricular (i.c.v.) isoprenaline significantly, though partially, attenuated the behavioural effect of chronic DMI by ₁-adrenoceptor-related mechanisms. Similarly, chronic i.c.v. co-administration of atenolol or practolol, ₁-adrenoceptor antagonists, together with DMI attenuated both-adrenoceptor down regulation and the behavioural activation by chronic DMI. On the other hand, chronic i.c.v administration of isoprenaline, supposedly leading to down regulation of-adrenoceptors, facilitated the activating behavioural effect of DMI, as a single dose became effective. Changes, however, in³H-DHA binding parameters in the cerebral cortex were not observed after chronic isoprenaline. These results suggest that down regulation of-adrenoceptors in brain is reponsible, at least in part, for the marked activatory effect of chronic DMI in the forced swimming test, possibly by reducing an inhibitory function of ₁-adrenoceptor mediated mechanisms.