Critical Factors in Sample Collection and Preparation for Clinical Metabolomics of Underexplored Biological Specimens

This review article compiles critical pre-analytical factors for sample collection and extraction of eight uncommon or underexplored biological specimens (human breast milk, ocular fluids, sebum, seminal plasma, sweat, hair, saliva, and cerebrospinal fluid) under the perspective of clinical metabolomics. These samples are interesting for metabolomics studies as they reflect the status of living organisms and can be applied for diagnostic purposes and biomarker discovery. Pre-collection and collection procedures are critical, requiring protocols to be standardized to avoid contamination and bias. Such procedures must consider cleaning the collection area, sample stimulation, diet, and food and drug intake, among other factors that impact the lack of homogeneity of the sample group. Precipitation of proteins and removal of salts and cell debris are the most used sample preparation procedures. This review intends to provide a global view of the practical aspects that most impact results, serving as a starting point for the designing of metabolomic experiments.

Analysis of Cannabinoids in Biological Specimens: An Update

Cannabinoids are still the most consumed drugs of abuse worldwide. Despite being considered less harmful to human health, particularly if compared with opiates or cocaine, cannabis consumption has important medico-legal and public health consequences. For this reason, the development and optimization of sensitive analytical methods that allow the determination of these compounds in different biological specimens is important, involving relevant efforts from laboratories. This paper will discuss cannabis consumption; toxicokinetics, the most detected compounds in biological samples; and characteristics of the latter. In addition, a comprehensive review of extraction methods and analytical tools available for cannabinoid detection in selected biological specimens will be reviewed. Important issues such as pitfalls and cut-off values will be considered.

Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid-liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.

Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

A Brief Review on Determination of Acenocoumarol in Biological and Pharmaceutical Specimens: Analytical Methodologies

Acenocoumarol is an oral anticoagulant medicinal agent is frequently prescribed for the prophylaxis and the management of thromboembolic events. Acenocoumarol is prescribed in the form of racemic mixture and S- form is a more influential isomer. Acenocoumarol starts quickly with action and absorption, and the effect lasts for 15-20 h. In most patients, the therapeutic prothrombin range is caused 36 h after the primary dose. This review offers a detailed overview of the various analytical methodologies published in the literature from 1976 to uptil now for evaluation acenocoumarol and its combinations in specimens. The present review also stated the chiral analytical methods for the quantification of its enantiomers. A detailed study of the work revealed several analytical methodologies are routinely used for estimation of acenocoumarol includes UV/Vis-Spectrophotometry, liquid chromatography-mass spectrophotometry, high-performance liquid-chromatography, gas chromatography, high-performance thin-layer chromatography, capillary electrophoresis, Fourier-transform infrared spectroscopy and many miscellaneous techniques. Pharmaceutical analysis carried out the prominent task to understand the knowledge of the physicochemical properties of the medicinal agent; since the establishment of a new analytical method is still a challenging task for a research scientist. Thus, the present review will help to research scientist for the development of new analytical methods for the acenocoumarol.

Novel synthetic opioids - toxicological aspects and analysis

Over the past few years, there has been an emerging number of new psychoactive drugs. These drugs are frequently mentioned as "legal highs", "herbal highs", "bath salts" and "research chemicals". They are mostly sold and advertised on online forums and on the dark web. The emerging new psychoactive substances are designed to mimic the effects of psychoactive groups, which are often abused drugs. Novel synthetic opioids are a new trend in this context and represent an alarming threat to public health. Given the wide number of fatalities related to these compounds reported within the last few years, it is an important task to accurately identify these compounds in biologic matrices in order to administer an effective treatment and reverse the respiratory depression caused by opioid related substances. Clinicians dealing with fentanyl intoxication cases should consider that it could, in fact, be a fentanyl analogue. For this reason, it is a helpful recommendation to include synthetic opioids in the routine toxicological screening procedures, including analysis in alternative matrices, if available, to investigate poly-drug use and possible tolerance to opioids. To address this public health problem, better international collaboration, effective legislation, effective investigation, control of suspicious "research chemicals" online forums and continuous community alertness are required. This article aims to review diverse reported fatalities associated with new synthetic opioids describing them in terms of pharmacology, metabolism, posology, available forms, as well as their toxic effects, highlighting the sample procedures and analytical techniques available for their detection and quantification in biological matrices.

Interpreting γ-hydroxybutyrate concentrations for clinical and forensic purposes

INTRODUCTION

γ-Hydroxybutyric acid is an endogenous substance, a therapeutic agent, and a recreational drug of abuse. This psychoactive substance acts as a depressant of the central nervous system and is commonly encountered in clinical and forensic practice, including impaired drivers, poisoned patients, and drug-related intoxication deaths.

OBJECTIVE

The aim of this review is to assist clinical and forensic practitioners with the interpretation of γ-hydroxybutyric acid concentrations in blood, urine, and alternative biological specimens from living and deceased persons.

METHODS

The information sources used to prepare this review were PubMed, Scopus, and Web-of-Science. These databases were searched using keywords γ-hydroxybutyrate (GHB), blood, urine, alternative specimens, non-conventional biological matrices, saliva, oral fluid, sweat, hair, vitreous humor (VH), brain, cerebrospinal fluid (CSF), dried blood spots (DBS), breast milk, and various combinations thereof. The resulting 4228 references were screened to exclude duplicates, which left 1980 articles for further consideration. These publications were carefully evaluated by taking into account the main aims of the review and 143 scientific papers were considered relevant. Analytical methods: The analytical methods used to determine γ-hydroxybutyric acid in blood and other biological specimens make use of gas- or liquid-chromatography coupled to mass spectrometry. These hyphenated techniques are accurate, precise, and specific for their intended purposes and the lower limit of quantitation in blood and other specimens is 0.5 mg/L or less. Human pharmacokinetics: GHB is rapidly absorbed from the gut and distributes into the total body water compartment. Only a small fraction of the dose (1-2%) is excreted unchanged in the urine. The plasma elimination half-life of γ-hydroxybutyric acid is short, being only about 0.5-0.9 h, which requires timely sampling of blood and other biological specimens for clinical and forensic analysis. Endogenous concentrations of GHB in blood: GHB is both an endogenous metabolite and a drug of abuse, which complicates interpretation of the laboratory results of analysis. Moreover, the concentrations of GHB in blood and other specimens tend to increase after sampling, especially in autopsy cases. This requires the use of practical "cut-off" concentrations to avoid reporting false positive results. These cut-offs are different for different biological specimen types. Concentrations of GHB in clinical and forensic practice: As a recreational drug GHB is predominantly used by young males (94%) with a mean age of 27.1 years. The mean (median) and range of concentrations in blood from apprehended drivers was 90 mg/L (82 mg/L) and 8-600 mg/L, respectively. The concentration distributions in blood taken from living and deceased persons overlapped, although the mean (median) and range of concentrations were higher in intoxication deaths; 640 mg/L (280 mg/L) and 30-9200 mg/L, respectively. Analysis of GHB in alternative specimens: All biological fluids and tissue containing water are suitable for the analysis of GHB. Examples of alternative specimens discussed in this review are CSF, saliva, hair strands, breast milk, DBS, VH, and brain tissue.

CONCLUSIONS

Body fluids for the analysis of GHB must be obtained as quickly as possible after a poisoned patient is admitted to hospital or after a person is arrested for a drug-related crime to enhance chances of detecting the drug. The sampling of urine lengthens the window of detection by 3-4 h compared with blood samples, but with longer delays between last intake of GHB and obtaining specimens, hair strands, and/or nails might be the only option. In postmortem toxicology, the concentrations of drugs tend to be more stable in bladder urine, VH, and CSF compared with blood, because these sampling sites are protected from the spread of bacteria from the gut. Accordingly, the relationship between blood and urine concentrations of GHB furnishes useful information when drug intoxication deaths are investigated.

Entomological Collections in the Age of Big Data

With a million described species and more than half a billion preserved specimens, the large scale of insect collections is unequaled by those of any other group. Advances in genomics, collection digitization, and imaging have begun to more fully harness the power that such large data stores can provide. These new approaches and technologies have transformed how entomological collections are managed and utilized. While genomic research has fundamentally changed the way many specimens are collected and curated, advances in technology have shown promise for extracting sequence data from the vast holdings already in museums. Efforts to mainstream specimen digitization have taken root and have accelerated traditional taxonomic studies as well as distribution modeling and global change research. Emerging imaging technologies such as microcomputed tomography and confocal laser scanning microscopy are changing how morphology can be investigated. This review provides an overview of how the realization of big data has transformed our field and what may lie in store.

Success rates for consent and collection of prenatal biological specimens in an epidemiologic survey of child health

BACKGROUND

The National Children's Study (NCS) Vanguard Study began enrollment in January 2009 as an initial pilot study for a planned large-scale, longitudinal U.S. cohort study of the effect of environmental influences on child health and development, with biological and environmental sample collection conducted in seven locations from April 2009 to October 2010. We sought to determine rates of consent for, and success of collection of, maternal and paternal biospecimens before and during pregnancy in the NCS Vanguard Study.

METHODS

Samples of blood, saliva, vaginal swabs, urine, hair, and nails were collected before and during pregnancy. All specimens were sent to a central repository for processing, storage, and quality assessment.

RESULTS

Of 780 pregnant women asked to consent to sample collection, 773 (>99%) agreed, and of 295 nonpregnant women, 292 (99%) agreed. Of 440 fathers asked to consent to sample collection, 435 (99%) agreed. Frequency of successful collection of biospecimens varied depending on sample and visit type. In descending order, the ranges over all visit types of the proportion of expected samples successfully collected from women were: urine, 92.5 to 95.7%; hair, 89.6 to 92.5%; vaginal swab, 84.2 to 88.5%; blood, 74.9 to 78.5%; 2-day saliva, 65.8 to 81.6%; and nails, 76.4 to 76.7%. For fathers, rates were highest for urine (94.9%) and lowest for hair (63.0%).

CONCLUSION

High rates of consent for and collection of a wide variety of biospecimens can be achieved in prospective epidemiologic cohort studies of pregnant women. Ease of sample collection may be a primary factor influencing successful biospecimen collection.

Attitudes and beliefs toward biobehavioural research participation: voices and concerns of urban adolescent females receiving outpatient mental health treatment

BACKGROUND

Biobehavioural research methodology can be invasive and burdensome for participants - particularly adolescents with mental illnesses. Human biological researchers should consider how methodological impositions may hinder adolescent research participation. However, literature on adolescent's voices and concerns toward biobehavioural research participation is virtually non-existent.

AIM

This study was designed to determine adolescents' perceptions of participation in research involving the collection of biomarkers via blood, saliva and/or urine samples.

SUBJECTS AND METHODS

Urban adolescent females (aged 12-19) receiving outpatient mental health treatment (n = 37) participated in focus groups with concurrent survey administration to explore attitudes, beliefs and willingness/intentions toward biobehavioural research participation.

RESULTS

Participants had favourable attitudes toward biobehavioural research and were amenable to provide each specimen type. Mistrust for research emerged, however, and concerns related to privacy and confidentiality were expressed.

CONCLUSION

Participant recruitment is a critical component in study design and implementation; this includes knowledge of population-specific recruitment barriers and facilitators. This innovative paper provides a context for the research participants' decision-making process, strategies to allay fears and concerns and concrete areas to target in research-related interventions. Although the findings are from a specific, US-based sample, the implications warrant replication of the research in other geosocial settings.

Navigating the cultural geography of indigenous peoples' attitude toward genetic research: the Ohana (family) heart project

Background

Little is known about the burden of heart failure among indigenous populations, including Native Hawaiians (NH). Recent concerns about genetic research in the NH community resonate with similar concerns raised by American Indian, Alaskan Native and Canadian First Nations communities and have raised questions about the best way to proceed with studies involving biological specimens.

Objective

To help us plan a study to investigate disparities in heart failure incidence and outcomes in a NH community, we performed a qualitative study to examine the community's expectations for heart failure research that includes the collection of biological specimens.

Methods

Eighty-five NH with a personal or family history of heart failure, who lived in a geographically isolated community in the state of Hawai‘i participated in 1 of 16 semi-structured interviews. Interviews were conducted in a standard manner, with open-ended questions designed to explore their expectations for a heart failure research study that included the collection of biological specimens. Interviews were analyzed thematically through iterative readings and coding.

Results

Four key themes regarding heart failure research with the use of biological specimens characterized their expectations: (a) Need to foster trust between investigator and community; (b) Establish a partnership with the community to identify needs and goals; (c) Need for mutual benefit to investigator and community; (d) Identification of a key voice to represent the community. Participants expressed strong support for research. However, the strength of that support was directly related to the strength of the relationship between the research team and the community. The collection of biological specimens for genetic analyses was not an explicit concern or barrier per se.

Conclusions

It appears feasible to conduct a heart failure research study that includes the collection of biological samples. However, success will likely require addressing the community's expectations, including the need for a long-term partnership built on trust and mutual benefit, and a key voice to represent the community.

Efficient determination of purine metabolites in brain tissue and serum by high-performance liquid chromatography with electrochemical and UV detection

The purine metabolic pathway has been implicated in neurodegeneration and neuroprotection. High-performance liquid chromatography (HPLC) is widely used to determine purines and metabolites. However, methods for analysis of multiple purines in a single analysis have not been standardized, especially in brain tissue. We report the development and validation of a reversed-phase HPLC method combining electrochemical and UV detection after a short gradient run to measure seven purine metabolites (adenosine, guanosine, inosine, guanine, hypoxanthine, xanthine and urate) from the entire purine metabolic pathway. The limit of detection (LoD) for each analyte was determined. The LoD using UV absorption was 0.001 mg/dL for hypoxanthine (Hyp), inosine (Ino), guanosine (Guo) and adenosine (Ado), and those using coulometric electrodes were 0.001 mg/dL for guanine (Gua), 0.0001 mg/dL for urate (UA) and 0.0005 mg/dL for xanthine (Xan). The intra- and inter-day coefficient of variance was generally <8%. Using this method, we determined basal levels of these metabolites in mouse brain and serum, as well as in post-mortem human brain. Peak identities were confirmed by enzyme degradation. Spike recovery was performed to assess accuracy. All recoveries fell within 80-120%. Our HPLC method provides a sensitive, rapid, reproducible and low-cost method for determining multiple purine metabolites in a single analysis in serum and brain specimens.

Liquid Chromatography-Tandem Mass Spectrometry Analysis of Opioids, Benzodiazepines, Cannabinoids, Amphetamines, and Cocaine in Biological and Other Specimens

The use of liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) or single-stage mass spectrometry (MS) is making significant inroads in the analyst's compendium of instrumentation available for the analysis of drugs in biological fluids, tissues, and other specimens of interest. LC/MS(/MS) has the unique capability of analyzing substances frequently not analyzable by any other means. Furthermore, LC/MS(/MS), particularly LC/MS/MS instrumentation, has shown a precipitous drop in cost, making it more accessible to the smaller laboratories. As such, an increasing number of methods for the analysis of drugs of abuse have been published using LC/MS(/MS) - in particular, those methods associated with LC/MS/MS. However, these methods are not without certain endemic problems/limitations such as ion source selection, matrix effects, endogenous interferences, and interlibrary matching of spectra. This review seeks to show what progress is being made to circumvent the perceived limitations of LC/MS(/MS). It presents methodologies for selected drugs of abuse (opioids, benzodiazepines, cannabinoids, cocaine, and the amphetamines) that have been developed in recent years for analysis in blood, urine, hair, and oral fluids, as well as certain other specimens. Emphasis is primarily directed toward those methodologies that have been developed recently for LC/MS/MS, but LC/MS methods are also addressed where appropriate.