Biomedical Laboratory Science

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Saturday, April 2, 2016

Your viruses could reveal your travel history, and much more.


The genomes of two distinct strains of the virus that causes the common lip cold sore, herpes simplex virus type 1, have been identified within an individual person --an achievement that could be useful to forensic scientists for tracing a person's history. The research also opens the door to understanding how a patient's viruses influence the course of disease.

Most people harbor HSV-1, frequently as a strain acquired from their mothers shortly after birth and carried for the rest of their lives. The new discovery was made with the help of a volunteer from the United States. The research revealed that one strain of the HSV-1 virus harbored by this individual is of a European/North American variety and the other is an Asian variety -- likely acquired during the volunteer's military service in the Korean War in the 1950s.

"It's possible that more people have their life history documented at the molecular level in the HSV-1 strains they carry," said Derek Gatherer, a lecturer in the Division of Biomedical and Life Sciences at Lancaster University in the United Kingdom and a member of the research team, which also includes scientists at Georgia State University, the University of Pittsburgh, and Princeton University.

Read more: Your viruses could reveal your travel history, and much more.

This is a reconstruction of a herpes simplex virus capsid, based on data from electron microscopy studies.
Source: sciencedaily

Human Myocardium is Bioengineered on Native Heart ‘Scaffold’.

Heart cells have been successfully grown in a human heart stripped of all cellular components by scientists at the Massachusetts General Hospital.

Using detergent, scientists removed all cells and human leukocyte antigens from 73 human hearts. The ‘matrix’ of the heart was then repopulated with pluripotent stem cells induced to differentiate into cardiac muscle. The scientists behind the work hope to create cardiac muscle to repair damaged tissue.

Professor Jacques Guyette, from the Massachusetts General Hospital (MGH) and lead author of this study, said: “Regenerating a whole heart is most certainly a long-term goal that is several years away, so we are currently working on engineering a functional myocardial patch that could replace cardiac tissue damaged due a heart attack or heart failure.”

In 2008, Dr Harold Ott, also from the MGH, developed a procedure to strip all cells from organs, leaving just the ‘scaffolding’ behind. To date, his technique has been used on hearts, lungs, livers, pancreases and kidneys.

MicroRNA molecules were used to reprogramme adult skin cells to created induced pluripotent stem cells (iPSC). It is hoped this method, as well as being more efficient, will be less likely to encounter regulatory issues.

Read more: Human Myocardium is Bioengineered on Native Heart ‘Scaffold’.


Source: labnews; thedailybeast

Friday, April 1, 2016

Your baby's Sex may be determined by ancient viral genes.

It's a boy! Or maybe it's a girl, but either way, new research suggests that the sex of mouse babies, and perhaps the sex of human babies, may be influenced by a newfound way to deactivate ancient viral genes that have been embedded in mammal genomes for more than a million years.

In the research, the scientists looked at viral DNA that is active in the mouse genome. Viral DNA can become part of an animal's genome when a kind of virus called a retrovirus infects a cell, and slips its genes into the DNA of host cells. (The most notorious retrovirus is HIV, the virus behind AIDS.)

If a retrovirus infects a sperm or egg cell — and that sperm or egg is involved in fertilization and becomes part of a person — all of the person's cells will have the viral DNA, and they will pass it on to their descendants. Hence, people and animals today carry in their cells the genetic remnants of viruses that invaded the genomes of their ancestors.

Read more: Your baby's Sex may be determined by ancient viral genes.


Source: Credit: EKS/Shutterstock

Video - Nucleotide Excision Repair of DNA.

In nucleotide excision repair (NER), damaged bases are cut out within a string of nucleotides, and replaced with DNA as directed by the undamaged template strand. This repair system is used to remove pyrimidine dimers formed by UV radiation as well as nucleotides modified by bulky chemical adducts. 

The common feature of damage that is repaired by nucleotide excision is that the modified nucleotides cause a significant distortion in the DNA helix. NER occurs in almost all organisms examined. Some of the best-characterized enzymes catalyzing this process are the UvrABC excinuclease and the UvrD helicase in E. coli. The genes encoding this repair function were discovered as mutants that are highly sensitive to UV damage, indicating that the mutants are defective in UV repair. 

Wild type E. coli cells are killed only at higher doses of UV radiation. Mutant strains can be identified that are substantially more sensitive to UV radiation; these are defective in the functions needed for UV-resistance, abbreviated uvr. By collecting large numbers of such mutants and testing them for their ability to restore resistance to UV radiation in combination, complementation groups were identified.

Four of the complementation groups, or genes, encode proteins that play major rules in NER; they are uvrA, uvrB, uvrC and uvrD.



Video Source: All About Molecular Biology

Pre-Analytical Errors in Biomedical Chemistry Laboratory

Detecting and minimizing pre-analytical variables in clinical analysis
Pre-analytical variables refers to any and all procedures that occur during sample collection, prior to sample analysis. This involves patient identification, physical sample collection, sample transportation to the testing site and sample preparation. 

Pre-analytical errors account for 32%-75% of laboratory errors1. These errors can have a significant impact on laboratory results and it is imperative that laboratory personnel are able to spot these erroneous results, rather than falsely attributing them to an underlying medical cause.

External pre-analytical variables
Some factors such as exercise, eating, drinking and medication can affect patient results. Eating and drinking affects glucose, triglycerides, alkaline phosphatase, alanine, aminotransferase, inorganic phosphate, cholesterol, folic acid, urea, potassium and more. It is recommended that a fasting sample be taken if these sensitive parameters are to be measured.

Exercise should not be undertaken immediately before blood tests such as CK, AST and LDH. In some cases, medication may be postponed for several days until a blood test can be taken, unless the blood test is for therapeutic drug monitoring purposes.

Read more: Pre-Analytical Errors in Biomedical ChemistryLaboratory

Pre-analytical variables account for 32%- 75% of laboratory errors
Source: selectscience

Troponins as cardiac injury markers

Cardiac injury occurs when there is disruption of normal cardiac myocyte membrane integrity. This results in the loss into the extracellular space (including blood) of intracellular constituents including detectable levels of a variety of biologically active cytosolic and structural proteins, referred to as biomarkers, such as troponin, creatine kinase, myoglobin, heart-type fatty acid binding protein, and lactate dehydrogenase. Injury is usually considered irreversible (cell death), but definitive proof that cell death is an inevitable consequence of the process is not available. 

When a sufficient number of myocytes have died (myocyte necrosis) or lost function, acute clinical disease is apparent. Ischemia, with or without infarction, consequent to an imbalance between the supply and demand of oxygen (and nutrients) is the most common cause of cardiac injury. Other causes include trauma, toxins, and viral infection.

The biochemical characteristics and utility of troponins, the diagnosis of cardiac injury, and acute myocardial infarction (MI) in particular will be reviewed here. The other biomarkers of cardiac injury and disease states, other than an acute MI, in which elevation of biomarkers are seen are discussed separately.

Read more: Troponins as cardiac injury markers

Source: sciencsnutshell

Thursday, March 31, 2016

Neuroimmunology of multiple sclerosis

Multiple sclerosis (MS) is a neuroinflammatory condition that affects the central nervous system and presents with various neurological and cognitive symptoms. Although these symptoms and the disease course of MS can vary considerably among affected individuals, most people with this condition exhibit a progressive accumulation of disability in the later phase of the disease.

This poster provides an overview of the pathophysiological contributions of both the immune system and the nervous system to MS and how these contributions change with disease progression. The poster also highlights the sites of action of the currently available drugs for MS and briefly touches on other therapeutic strategies that are being explored.

Calliope A. Dendrou, Robin J. Franklin and Lars Fugger


Immunoneurobiology Poster of Multiple Scelerosis

Source: nature.com

Mother's microbiome influence her offspring's immune system during gestation.

During gestation, a mother's microbiome shapes the immune system of her offspring, a new study in mice suggests. While it's known that a newborn's gut microbiota can affect its own immune system, the impact of a mother's microbiota on her offspring has largely been unexplored.

Here, Mercedes Gomez de Agüero et al. infected the guts of pregnant mice with E.coli engineered to dwindle over time, allowing the mothers to become germ-free again around the time they gave birth.

This temporary colonization of E.coli in the mother affected the immune system of her offspring; after birth, the offspring harbored more innate lymphoid and mononuclear cells in their intestines compared to mice born to microbe-free pregnant mothers. Similar results were seen when pregnant mothers were temporarily colonized with a cocktail of eight other microbes.

An RNA analysis of offspring born to gestation-only colonized mothers compared with controls revealed greater expression of numerous genes, including those that influence cell division and differentiation, mucus and ion channels, and metabolism and immune function.

By transferring serum from bacteria-colonized pregnant mice to non-colonized pregnant mice, the researchers found that maternal antibodies likely facilitate the transmission and retention of microbial molecules from a mother to her offspring.

Read more: Mother's microbiome influence her offspring's immune system during gestation.
Shaping of the immune system starts with the maternal microbiota.
Source: sciencedaily

Pondering my PhD worth after graduation.

Her PhD on Parkinson’s disease didn’t go exactly as planned, but in the end the difficulties made Liesbeth Aerts a happier scientist.

One year ago today, I found myself in a lecture theatre, presenting my research to a thesis jury. During the years leading up to that moment, there were many days when I worried whether I was ever going to make it that far. When I finally did, most of all, I felt relieved.

Like many others, I had imagined my PhD differently. I was prepared for the hard work and long hours. I thought that if I gave it my all, I would be a successful scientist. My ambitions took a blow when faced with failure after failure. For well over a year, I felt like a fraud, having fooled my supervisors and myself into thinking that I had what it took to become a good scientist. Looking back, I’d tell my younger self to take it easy.

Cut yourself some slack

Even Nobel prize winners were first-year students once. They messed up their experiments, needed help and most likely suffered just as much as you did. Don’t expect to do everything right the first time around. No matter how hard you work and how motivated you are, you’ll need to accept that becoming better takes time and requires failure.

One mistake at a time, I got better, and as time went by, I realised others were making educated guesses just like I was. They too didn’t understand everything during seminars. Could it be that, just maybe, I wasn’t the dumbest person in the room?

Read more: Pondering my PhD worth after graduation.


Source: blogs.nature.com

Troponin I and Brain Natriuretic Peptide Antibodies as new Generation of Cardiac Markers.

HyTest specialists have been involved in cardiac troponin I (cTnI) studies for more than 15 years. Currently many well characterised antibodies directed to different regions of the cTnI molecule are available. Many of these antibodies are used in commercial assays. The company has determined antibody pairs and combinations useful for the development of high sensitivity cTnI assays, and also validated pairs suitable for lateral flow assays. A new generation of cTnI antibodies is currently under development.

Work with brain natriuretic peptides is ongoing, and BNP, proBNP and NT-proBNP antibodies and antigens are available. In addition a new type of BNP/proBNP immunoassay, the "single epitope" sandwich assay, has been developed, which differs from the conventional format of sandwich immunoassays. In the single epitope sandwich assay, the capture antibody recognises the antigen (BNP or proBNP), whereas the detection antibody is specific to the complex of capture antibody and antigen. The single epitope sandwich approach has great advantages compared with conventional assays, especially in the case of unstable antigen detection. HyTest holds the intellectual property rights for this invention.




Source: cli-online, bpac, stmd
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