Biomedical Laboratory Science

Wednesday, March 30, 2016

Clinical Considerations for High-Sensitivity Cardiac Troponin Assays.

Cardiac troponins (cTn) have been available for nearly 2 decades in clinical laboratories and are now considered the gold standard for biochemical detection of myocardial infarction (MI). Furthermore, multiple organizations have endorsed the biomarkers’ use in both clinical and analytical guidelines. Today, the universal definition of MI includes the typical rise and/or fall of cTn with at least one value above the 99th percentile of a healthy reference population accompanied by at least one of the following clinical factors: presence of ischemic symptoms; electrocardiographic changes; or imaging evidence of loss of viable myocardium or a new wall motion abnormality.

However, a growing body of evidence now suggests that very low cTn values are clinically important. Investigators have found that patients who have cTn elevations considered normal, but near the 99th percentile, have worse prognoses and require more aggressive clinical management. These findings have prompted the search for newer techniques to enhance precision and enable measurements of cTn at or even below the 99th percentile cutoff.

Recently, researchers and commercial manufacturers have developed several high-sensitivity assays for cardiac troponin (hs-cTn) that are expected to be available soon for routine clinical use in the U.S. Understanding their analytical and clinical performance will be extremely important because under the current MI definition, a significant proportion of the general population would have evidence of myocardial injury. In this article, we will review the basic analytical and clinical characteristics of hs-cTn assays that are important for laboratory professionals to understand and describe how best to help clinicians employ these powerful assays.

Source: aacc, shutterstock

Tuesday, March 29, 2016

Tweaking Gut Bacteria Could help Prevent Brain Strokes

Recent research has shown how fundamentally important the bacteria in our gut are to the rest of our mental and physical health, affecting everything from our appetite to our state of mind.

Now a new study suggests that our gut bacteria could even play a role in protecting us from brain damage, with an experiment involving mice showing that certain types of stomach microbes can actually help reduce the severity of strokes.

"Our experiment shows a new relationship between the brain and the intestine,"said neuroscientist Josef Anrather from the Feil Family Brain and Mind Research Institute at Cornell University. "The intestinal microbiota shape stroke outcome, which will have an impact [on] how the medical community views stroke and defines stroke risk."

Anrather and his colleagues analyed two groups of mice – one received a combination of antibiotics that tweaked their gut microbiota, and the other acted as a control group, with no alterations made to their gut microbiota over the course of the experiment.

Source: anufrench

Biochemical Markers of Alcohol Consumption

Biochemical markers of alcohol intake can be separated into two categories: direct markers of ethanol metabolism and indirect markers. The different alcohol markers have varying time windows of detection and are a useful additional tool to detect alcohol intake in alcohol-dependent clients.

Introduction

Alcohol dependence is characterized by craving, tolerance, a preoccupation with alcohol and continued drinking in spite of harmful consequences. The World Health Organization Alcohol Use Disorders Identification Test (AUDIT) is recommended for the identification of individuals that are dependent on alcohol [1]. The prevalence of alcohol use disorders (including dependence and harmful use of alcohol) is 11.1% in the UK compared to 7.5% across Europe [2]. In England, 250 000 people are believed to be moderately or severely dependent and require intensive treatment [3].

Figure 1. The metabolism and excretion of ethanol. The size of the arrow demonstrates the proportion of the ethanol consumed that is excreted via each mechanism. Over 95% is metabolized to acetaldehyde and acetic acid. Less than 0.1% is metabolized to ethyl glucuronide and ethyl sulphate.

Alcohol use is the third leading risk factor contributing to the global burden of disease after high blood pressure and tobacco smoking [4]. In 2012, 3.3 million deaths (5.9% of all global deaths) were attributable to alcohol consumption [2]. It is estimated that the UK National Health Service (NHS) spends £3.5 billion/year in costs related to alcohol and the number of alcohol-related admissions has doubled over the last 15 years [3].

Table 1. Alcohol markers: time window of detection and limitations. GGT, gamma glutamyl transferase; MCV, mean corpuscular volume; PEth, phosphatidylethanol.

Source: Cli-Online

A Typical Day of a Biomedical Scientist in Biochemistry Lab

It’s 8 p.m. on Sunday night and I’ve just taken over from my colleague who had a busy day and was very pleased to see me!

For the next 12 hours I shall be the on-call biomedical scientist for the department of Biochemistry at St. Peter’s Hospital, Ashford performing diagnostic blood tests on urgent samples taken from those patients who are in need of urgent medical attention. I expect to receive samples from the Accident and Emergency Department (A/E), from ITU, the Special Care Baby Unit, the Maternity Unit, the children’s’ wards and from everywhere else in the hospital.

The first thing to do is to make checks on the huge automated analysers that are interfaced to the pathology computer. I’m running the quality controls now, which must produce results within strict ranges before I can analyse any patients’ blood tests. I’ll be making absolutely sure that the analysers are producing accurate results and that everything is documented.

My bleep has just gone off telling me to phone A/E about some bloods are coming down the air-chute syste, they are from a 2 year old with a rash and possible meningitis. I make my way along the corridor to the Pathology Reception, where samples are received and prepared, to look for the samples, and make a mental note that some time tonight they are quite likely to decide to take some cerebrospinal fluid for analysis from this patient.

I start work on this tiny blood sample, carefully separating the serum from the blood cells, and before too long it is on the analyser and I can dash back to pick up the rest of the samples which are now arriving in quick succession.

The bleep has been going crazy and there’s lot to do – a road traffic accident patient has been brought into A/E. They don’t know his name so have given him a special emergency ID with a special red ID number. Results are needed fast and they have also been talking to the on-call transfusion specialist. We are working together swiftly handling these urgent samples, checking them carefully, giving them a unique computer ID, entering data onto the computer which will interface with the analysers in both our departments. And then finally we are away back to our laboratories.

Name: Simon Andrews

Works at: Biochemistry department, St Peters and Ashford Hospital

Career: Graduated with a BSc degree in biomedical science from the University of East London (accredited by the IBMS).

Source: CampusSteps

What Does a Medical Laboratory Technician Do?

You’ve heard about the exciting career opportunity in the healthcare industry, but you don’t exactly picture yourself as a nurse. It’s important to know that not all healthcare careers involve direct patient care. There are in-demand opportunities in the field that allow you to work behind-the-scenes while still having a positive impact on people’s health.

Becoming a medical lab tech (MLT) is one of those opportunities. The bright future of this field is indicated by the 30 percent projected increase in jobs through 2022, according to the Bureau of Labor Statistics (BLS).

That stat alone should pique your interest about this career. But it’s not enough to make up your mind. Before choosing to pursue this profession, you need to be able to answer the following question: What does a medical lab tech do?

So what does a medical lab tech do? They work in laboratory settings that aid in disease and illness diagnosis – but that is merely the tip of the iceberg. The variety of duties that an MLT performs makes it an ever-changing position that demands creativity and problem-solving skills.

But before you can realize you want to become a medical lab technician, you should be able to answer the following question: what does a medical lab technician do, anyway? Keep reading to find your answer!

Source: Rasmussen College

Career Path Guide: How to Become a Clinical Chemist?

If you want to become a clinical chemist, you first need to determine if this career path is a good fit for you. If the following description sounds like you, then you’re probably well suited for a career as a clinical chemist:

Those who become clinical chemists have a keen interest in contributing to the body of knowledge of medical science, as well as helping healthcare practitioners save lives and improving the quality of life of patients by helping with early detection of various diseases and health conditions.

In order to become a clinical chemist, you will also need the emotional and intellectual capacity to complete all of the necessary academic work. You will also need a high stress tolerance, as this is required for when you don’t achieve immediate results in your work.

If you want to become a clinical chemist, you should be comfortable working in a laboratory or a clinical setting, and you should be comfortable sharing your opinions and findings with others. You will also need a good amount of manual dexterity in order to accomplish many tasks in this career, such as performing tests and using specialized equipment.

Below we've outlined what you'll need to begin a career as a clinical chemist. We've also included helpful information for this career, such as job description, job duties, salary expectations, a list of possible employers and much more!

Source: AcademicInvest

Monday, March 28, 2016

Clinical Trial Risks

Clinical trials are research studies designed to answer a specific question which would then serve to improve current medical care. These studies focus on which medical treatment works best for a specific population of people with a certain disease. Usually a clinical trial is developed after there is some pre-clinical success or promising results in studies done in the laboratory.

Clinical trials are usually categorized as phase I, phase II or phase III. Phase I studies are done very early in drug development and usually focus on patient safety and trying to find the right dose that is tolerable. Later-phase studies tend to be more disease-specific and may compare an investigational treatment approach to the standard of care to see if there is any benefit with the new treatment.

Each clinical trial has its own inclusion and exclusion criteria. This helps make sure there is uniformity within the trial and that there are no outside factors which could influence the outcome of the study. Clinical trials help improve medical care and are necessary when seeking FDA approval for use within the general population.

Plasma DNA Tissue Mapping for Cancer Diagnosis

Using blood plasma samples to detect cancer and pinpoint its anatomical location could be just a few years away from regular medical practice. Dubbed plasma DNA tissue mapping, the approach will allow doctors to ‘visualize’ which organs are affected by cancer, and at what stage, through a blood test.

Choh Ming-li Professor of Chemical Pathology and Assistant Dean (Research) at the Faculty of Medicine at The Chinese University of Hong Kong, Professor Rossa Chiu, says the latest developments in human plasma cancer DNA analysis are pushing new boundaries.

“We have developed a brand new technology which takes cancer DNA analysis in plasma, often referred to as ‘liquid biopsies’, to the next level. It can detect abnormal DNA caused by cancer, and also allow us to scan a blood sample in order to locate which organ it is coming from. In simple terms, it enables us to take a CT scan of the blood,” she explains.

“For instance, we might be able to identify that 10% of the DNA in the blood plasma is from the liver and so we know that person has a tumor located in the liver. In the past we have tried to find a marker for liver cancer, but every cancer is very different and no single marker is particularly useful for a specific type of cancer. That means previously we would have detected cancer in a blood sample, then we would do a radiological imaging examination to see if there are shadows in any parts of the body.”

Source: ePathWay

Ebola Virus - Amplification-free direct detection on a hybrid optofluidic platform

Low-complexity detection of infectious diseases with high sensitivity and specificity is urgently needed, especially in resource-limited settings. Optofluidic integration combines clinical sample preparation with optical sensing on a single chip-scale system, enabling the direct, amplification-free detection of single RNA from Ebola viruses. The optofluidic system fulfills all key requirements for chip-based clinical analysis, including a low limit of detection, wide dynamic range, and the ability to detect multiple pathogens simultaneously.

Illustration of a virus and blood cells (Shutterstock)

Introduction

The recent Ebola and Zika outbreaks [1, 2] have made it clear that viral infections continue to pose diverse and widespread threats to humanity. Resource-limited settings, in particular, call for diagnostic devices and technologies that are robust and feature relatively low complexity for easy handling by potentially unskilled personnel. At the same time, such instruments need to fulfill all the technical requirements for accurate and reliable diagnosis. These include a limit of detection and dynamic range that are compatible with clinically observed viral loads as well as the ability to carry out multiplexed differential detection by screening simultaneously for several pathogens with similar clinical symptoms.

Figure 1. (a) Cross-sectional view of liquid-core ARROW. (b) Schematic of Automaton integrated with ARROW chip. (c) A hybrid optofluidic ARROW system. (d) Digitized fluorescence signal counts above background. (e) Concentration-dependent RNA counts for off-chip (open squares) and using the automaton (solid circles) sample preparation. Negative controls (SUDV, MARV) did not create any counts. Dashed line indicates predicted particle count determined from initial concentration and experimental parameters. EBOV, Zaire Ebola virus; MARV, Marburg virus; SUDV, Sudan Ebola virus. (Adapted from Cai et al., 2015 [12])

The 'gold standard' test for hemorrhagic fevers as well as other infectious diseases is real-time polymerase chain reaction (RT-PCR) [3]. PCR fulfills the sensitivity and specificity requirement for clinical testing. However, it is not ideal for resource-limited environments and point-of-care applications because of to its complexity. An alternative economic and portable option is antigen-capture enzyme-linked immunosorbent assay (ELISA) testing. However, ELISA requires more highly concentrated samples and thus its clinical application, especially for early disease detection, is restricted.

For the last two decades, the lab-on-chip approach, which features a small footprint and sample volume, has been considered as a promising candidate for the next generation low-complexity medical diagnostics [4]. Among all the approaches, optofluidics, which integrates optics and microfluidics in the same platform, has received increased attention [5, 6]. Microfluidics is ideal for performing biological sample processing on a chip-scale level and leads to miniaturization and simplification of the current diagnostic system. If it can be integrated with an optical sensing/read-out platform that enables high detection sensitivity down to the single pathogen level, an analytic system for which nucleic acid amplification is no longer needed becomes possible.

Figure 2. (a) Schematic of multi-mode interferometer (MMI) waveguide intersecting with liquid-core ARROW. (b) Excitation spots, 9 (blue), 8 (green), and 7 (red), generated by the MMI at wavelength of 488nm, 553nm and 633nm, respectively. (c) Optical signal detected from various labelled single virus particles. (Adapted from Ozcelik et al., 2016 [14])

In order to detect single molecular biomarkers and bioparticles, an in-flow based detection scheme is preferred. In a typical in-flow detection scheme, bioparticles are transported to the sensing region in a stream of gas or liquid where they are detected in transient fashion as they pass an optical interrogation region [7, 8]. Therefore, fast read-out of the optical signal from single bioparticles in sequence can be achieved, and many concerns associated with traditional surface-based sensing schemes such as unwanted nonspecific binding, probe photobleaching, and diffusion-limited transportation are eliminated.

Source: cli-online.com

Biomedical Laboratory Science