Zebrafish as a genetic model in pre-clinical drug testing and screening

The traditional drug discovery pipeline for the identification and development of compounds that selectively target specific molecules to ameliorate disease remains a major focus for medical research. However, the zebrafish is increasingly providing alternative strategies for various components of this pipeline. Zebrafish and their embryos are small, easily accessible and relatively low cost, making them applicable to high-throughput, small molecule screening. Zebrafish can also be manipulated by a range of forward and reverse genetics techniques to facilitate gene discovery and functional studies. Moreover, their physiological and developmental complexity provides accurate models of human disease to underpin mechanism of action and in vivo validation studies. Finally, several of these biological characteristics make zebrafish eminently suitable for toxicity testing, including eco-toxicology. Here we review the application of zebrafish to preclinical drug development and toxicity testing, including recent advances in mutant generation, drug screening and toxicology that serve to further enhance the capabilities of this valuable model organism in drug discovery.

A rapid test for heroin (3,6-Diacetylmorphine) based on two chemiluminescence reactions

A rapid method for screening drug seizure samples for 3,6-diacetylmorphine (heroin), which consists of a simple hydrolysis procedure and flow-injection analysis with two chemiluminescence reagents, is described. Before hydrolysis, 3,6-diacetylmorphine evokes an intense response with a tris(2,2'-bipyridyl)ruthenium(III) reagent (prepared by dissolving the perchlorate salt in acetonitrile), and a relatively weak chemiluminescence response with a second reagent: potassium permanganate in an aqueous acidic polyphosphate solution. However, the permanganate reagent is extremely sensitive toward the hydrolysis products of 3,6-diacetylmorphine (i.e., 6-monoacetylmorphine and morphine). Some compounds commonly found in drug laboratories may cause false positives with tris(2,2'-bipyridyl)ruthenium(III), but do not produce the markedly increased response with the permanganate reagent after the hydrolysis procedure. The combination of these two tests therefore provides an effective presumptive test for the presence of 3,6-diacetylmorphine, which we have verified with 14 samples obtained from a forensic science laboratory.

Apoptosis goes on a chip : advances in the microfluidic analysis of programmed cell death

Recent years have brought enormous progress in cell-based lab-on-a-chip technologies, allowing dynamic studies of cell death with an unprecedented accuracy. As interest in the microfabricated technologies for cell-based bioassays is rapidly gaining momentum, we highlight the most promising technologies that provide a new outlook for the rapid assessment of programmed and accidental cell death and are applicable in drug discovery, high-content drug screening, and personalized clinical diagnostics.

Integrated RNA extraction and RT-PCR for semi-quantitative gene expression studies on a microfluidic device

This paper describes the development of a microfluidic methodology, using RNA extraction and reverse transcription PCR, for investigating expression levels of cytochrome P450 genes. Cytochrome P450 enzymes are involved in the metabolism of xenobiotics, including many commonly prescribed drugs, therefore information on their expression is useful in both pharmaceutical and clinical settings. RNA extraction, from rat liver tissue or primary rat hepatocytes, was performed using a silica-based solid-phase extraction technique. Following elution of the purified RNA, amplification of target sequences for the housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the cytochrome P450 gene CYP1A2, was carried out using a one-step reverse transcription PCR. Once the microfluidic methodology had been optimized, analysis of control and 3-methylcholanthrene-induced primary rat hepatocytes were used to evaluate the system. As expected, GAPDH was consistently expressed, whereas CYP1A2 levels were found to be raised in the drug-treated samples. The proposed system offers an initial platform for development of both rapid throughput analyzers for pharmaceutical drug screening and point-of-care diagnostic tests to aid provision of drug regimens, which can be tailor-made to the individual patient.

Medulloblastoma Down Under 2013 : a report from the third annual meeting of the International Medulloblastoma Working Group.

Medulloblastoma is curable in approximately 70% of patients. Over the past decade, progress in improving survival using conventional therapies has stalled, resulting in reduced quality of life due to treatment-related side effects, which are a major concern in survivors. The vast amount of genomic and molecular data generated over the last 5-10 years encourages optimism that improved risk stratification and new molecular targets will improve outcomes. It is now clear that medulloblastoma is not a single-disease entity, but instead consists of at least four distinct molecular subgroups: WNT/Wingless, Sonic Hedgehog, Group 3, and Group 4. The Medulloblastoma Down Under 2013 meeting, which convened at Bunker Bay, Australia, brought together 50 leading clinicians and scientists. The 2-day agenda included focused sessions on pathology and molecular stratification, genomics and mouse models, high-throughput drug screening, and clinical trial design. The meeting established a global action plan to translate novel biologic insights and drug targeting into treatment regimens to improve outcomes. A consensus was reached in several key areas, with the most important being that a novel classification scheme for medulloblastoma based on the four molecular subgroups, as well as histopathologic features, should be presented for consideration in the upcoming fifth edition of the World Health Organization's classification of tumours of the central nervous system. Three other notable areas of agreement were as follows: (1) to establish a central repository of annotated mouse models that are readily accessible and freely available to the international research community; (2) to institute common eligibility criteria between the Children's Oncology Group and the International Society of Paediatric Oncology Europe and initiate joint or parallel clinical trials; (3) to share preliminary high-throughput screening data across discovery labs to hasten the development of novel therapeutics. Medulloblastoma Down Under 2013 was an effective forum for meaningful discussion, which resulted in enhancing international collaborative clinical and translational research of this rare disease. This template could be applied to other fields to devise global action plans addressing all aspects of a disease, from improved disease classification, treatment stratification, and drug targeting to superior treatment regimens to be assessed in cooperative international clinical trials.

Implementation and evaluation of brief depression and anxiety screening in clients contacting a drug and alcohol service

Introduction and Aims. High prevalence mental health (HPMH) comorbidity is common in clients seeking alcohol and other drug (AOD) treatment yet can remain undetected. Although research has reported on the introduction of screening into AOD services, little research has reported on the processes surrounding the introduction or evaluated its effectiveness.This study reports on the implementation and evaluation of brief anxiety and depression screening within a specialised, publicly funded AOD service in South-East Victoria.
Design and Methods. Study one examined the implementation of standardised HPMH screening with 114 adult clients (Mean age = 35.49, SD = 9.53; 64% male) telephoning an AOD service over a 5 week period. Measures included severity of HPMH problems,AOD use, care plans and referrals. Study two used semistructured interviews with nine staff/managers to evaluate the effectiveness of screening and its impact on service delivery.
Results. Ninety-four per cent of clients were identified at risk of anxiety or depression. Most care plans incorporated counselling, and concurrent referrals commonly involved a general practitioner. Staff and management found systematic screening increased identification and understanding of comorbid issues and enhanced client interaction but impacted on resource requirements.
Discussion and Conclusions. Most AOD treatment seekers were identified HPMH comorbid and care plans generally included counselling.Adjunctive referrals were more common for severely depressed clients. Screening was effective and enhanced client rapport.Evaluations revealed low confidence in treating HPMH issues in-house.Training may increase worker confidence in managing mental health interventions with subclinical cases, enhancing services’ ability to move towards dual diagnosis capability.

Screening and intervention for mental health problems in alcohol and other drug settings: Can training change practitioner behaviour?

Aims: The comorbidity of substance use and mental health problems poses a significant challenge for alcohol and other drug (AOD) treatment services. In many cases, AOD practitioners do not have experience or training in identifying or managing mental health conditions. Methods: This project examined the implementation of screening and intervention practices for mental health disorders among AOD clients. Training and supervision was provided to 20 AOD practitioners across five sites in four agencies with a focus on enhancing skills in detection of, and intervention for, mental health conditions among their clients. A package developed for this purpose, known as PsyCheck, was used. A random file audit was undertaken to examine changes in detection of mental health conditions. Findings: There were significant improvements in detection after training and supervision, with detection rates almost doubling in this time. Conclusions: Training and supervision using the PsyCheck package appears to have the potential to improve mental health detection and intervention in AOD services. This study shows promise for the implementation of mental health intervention in AOD services.

A screening test for heroin based on sequential injection analysis with dual-reagent chemiluminescence detection

A sequential injection analysis procedure with dual-reagent chemiluminescence detection was applied to the screening of street drug seizure samples for the presence of heroin. The chemiluminescence reagents (acidic potassium permanganate and tris(2,2′-bipyridine)ruthenium(III)) were aspirated from either side of a sample aliquot that was sufficiently large to prevent interdispersion of the reagent zones, and therefore two different chemical reactions could be performed simultaneously at either end of the sample zone. The presence of heroin in seizure samples was indicated by a strong response with the tris(2,2′-bipyridine)ruthenium(III) reagent and confirmed by a significant increase in the response with the permanganate reagent when the sample was treated with sodium hydroxide to hydrolyse the heroin to morphine. Nicomorphine (a morphine-derived pharmaceutical) was synthesised and tested under the same conditions. The responses with the permanganate reagent were similar to those for heroin, which supports the proposed chemical basis for the test. However, the responses with tris(2,2′-bipyridine)ruthenium(III) were far lower for nicomorphine than heroin (approximately 5-fold for the samples that had not been hydrolysed).

Evaluation of a community-based mental health drug and alcohol nurse in the care of people living with HIV/AIDS

There is a growing need for advanced practice mental health and drug and alcohol nursing roles in the care of people living with HIV/AIDS; however, limited publications address these domains. This study evaluated a community-based mental health drug and alcohol nurse role caring for people living with HIV/AIDS (Mental Health D&A Nurse) in a large not-for-profit district nursing organization providing care to people living with HIV/AIDS in an Australian city. Outcomes from a client assessment and 6–8-week follow-up by the Mental Health D&A Nurse are presented as captured by the Depression Anxiety Stress Scales (DASS 21), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), Health of the Nation Outcome Scales (HONOS) and WHOQoL BREF. Mean scores and caseness were analysed, and significant differences were found on the 'impairment' and 'social problems' subscales of the HONOS. Results of semi-structured interviews with clients describe effective and supportive mental health care and health-promoting education following visits by the Mental Health D&A Nurse. These positive findings support continuing implementation of the role within this community setting and indicate that even greater benefits will ensue as the role develops further. Findings are of interest to clinicians and policy makers seeking to implement similar roles in community-based HIV/AIDS care.

The utility of the Mood Disorders Questionnaire as a screening tool in a methadone maintenance treatment program

Objective. Comorbid mental illness amongst methadone maintenance therapy clients may be common and screening may be warranted. The Mood Disorders Questionnaire (MDQ) is a screening tool for bipolar disorder that has been validated in other treatment settings. Its utility for patients with substance use disorders is assessed in this study.

Methods. Clients of a methadone maintenance program were invited to complete the MDQ when they attended a public Drug and Alcohol Service for their regular scheduled appointments. Information about their history of substance use was also collected.

Results. Eighty clients (43 females, 37 males) aged 35 8.0 years (mean SD) participated in the study. Seventy-four clients completed the MDQ of which 36 (48.6%) obtained a positive screen. A check of client fi les suggested that only three of the 74 participants had a current working diagnosis of bipolar disorder. These three participants had screened positive on the MDQ.

Conclusions. There was a high prevalence of manic symptoms reported by participants, suggesting that screening for bipolar disorder in this population may be warranted. However, there is a risk of false positives with the MDQ, as it does not clearly differentiate between symptoms of mania and drug intoxication.

Introducing mental health and substance use screening into a community-based health service in Australia : usefulness and implications for service change

Mental health issues such as depression or anxiety and alcohol or other drug (AOD) problems often remain undiagnosed and untreated despite their prevalence in the community. This paper reports on the implementation and evaluation of an AOD and depression/anxiety screening programme within two Community Health Services (CHS) in Australia. Study 1 examined results from 5 weeks of screening (March–April 2008) using the Patient Health Questionnaire (two- and nine-item, Kroenke et al. 2001, 2003), the Conjoint Screen for Alcohol and other Drug Problems (Brown et al. 2001) and the Alcohol, Smoking and Substance Involvement Screening Test (Humeniuk & Ali 2006). Of the 55 clients screened, 33% were at risk of depression or anxiety, 22% reporting moderate-severe depression. Thirteen per cent were at risk of substance use disorders. A substantial proportion of at-risk clients were not currently accessing help for these issues from the CHS and therefore screening can facilitate identification and treatment referral. However, the majority of eligible clients were not screened, limiting screening reach. A second study evaluated the screening implementation from a process perspective via thematic analysis of focus group data from six managers and 14 intake/assessment workers (April 2008). This showed that when screening occurred, it facilitated opportunities for education and intervention with at-risk clients, although cultural mores, privacy concerns and shame/stigma could affect accuracy of screen scores at times. Importantly, the evaluation revealed that most decisions not to screen were made by workers, not by clients. Reasons for non-screening related to worker discomfort in asking sensitive questions and/or managing client distress, and a reluctance to spend long periods of time screening in time-pressured environments. The evaluation suggested that these problems could be resolved by splitting screening responsibilities, enhancing worker training and expanding follow-up screening. Findings will inform any community-based health system considering introducing screening.

Screening, referral and treatment for depression in patients with coronary heart disease: a consensus statement from the National Heart Foundation of Australia

In 2003, the National Heart Foundation of Australia position statement on “stress” and heart disease found that depression was an important risk factor for coronary heart disease (CHD). This 2013 statement updates the evidence on depression (mild, moderate and severe) in patients with CHD, and provides guidance for health professionals on screening and treatment for depression in patients with CHD.

The prevalence of depression is high in patients with CHD and it has a significant impact on the patient’s quality of life and adherence to therapy, and an independent effect on prognosis. Rates of major depressive disorder of around 15% have been reported in patients after myocardial infarction or coronary artery bypass grafting.

To provide the best possible care, it is important to recognise depression in patients with CHD. Routine screening for depression in all patients with CHD is indicated at first presentation, and again at the next follow-up appointment. A follow-up screen should occur 2–3 months after a CHD event. Screening should then be considered on a yearly basis, as for any other major risk factor for CHD.

A simple tool for initial screening, such as the Patient Health Questionnaire-2 (PHQ-2) or the short-form Cardiac Depression Scale (CDS), can be incorporated into usual clinical practice with minimum interference, and may increase uptake of screening.

Patients with positive screening results may need further evaluation. Appropriate treatment should be commenced, and the patient monitored. If screening is followed by comprehensive care, depression outcomes are likely to be improved.

Patients with CHD and depression respond to cognitive behaviour therapy, collaborative care, exercise and some drug therapies in a similar way to the general population. However, tricyclic antidepressant drugs may worsen CHD outcomes and should be avoided.

Coordination of care between health care providers is essential for optimal outcomes for patients. The benefits of treating depression include improved quality of life, improved adherence to other therapies and, potentially, improved CHD outcomes.