- Blood collection and testing
- Blood component description
- Preparation and usage
- Red blood cell antigens and antibodies
- Specialized component processing
- Specialized transfusion situations
- Transfusion-transmitted diseases
- Transfusion reactions
- Infectious complications of transfusion
- Therapeutic apheresis and quality
- Acute bleeding and massive transfusion
- Transfusion of the patient with a coagulopathy
- Transfusion of obstetrics, pediatric, immunocompromised, and platelet refractory patients
- Up-to-date references to all aspects of transfusion medicine
- File Name Handbook of Transfusion Medicine
- Edition 1st
- Year 2001
- Editor(s) Christopher Hillyer, Krista L. Hillyer, Frank Strobl, Leigh Jefferies, Leslie Silberstein
- ISBN-10 0123487757
- ISBN-13 978-0123487759
- Size 4.89 MB
- File Format .pdf
- Password bioscience.pk
- File Name Advances in Hematopoietic Stem Cell Research
- Edition 1st
- Year 2012
- Editor(s) Rosana Pelayo
- ISBN 978-953-307-930-1
- Publisher InTech
- Size 19.5 MB
- File Format .pdf
- Password bioscience.pk
- File Name Multiple Myeloma – A New Era of Treatment Strategies
- Edition 1st
- Year 2012
- Author(s) Klaus Podar, Kenneth C. Anderson
- ISBN 978-1-60805-297-4
- Publisher Bentham Science Publishers
- Size 10.9 MB
- File Format .pdf
- Password bioscience.pk
Two years have passed since the CDC finally published guidelines addressing HIV laboratory testing and officially endorsed the “new” HIV laboratory testing algorithm. Although many had become aware of the algorithm in the four years prior, and had adopted it to various degrees, this was the final word on this long-awaited guidance. The algorithm gained visibility prior to the official endorsement mainly because it had been heavily referenced in CDC publications and numerous scientific articles.
Advantages of the new algorithm
Why is the new algorithm superior to the old algorithm? First, the new algorithm emphasizes the use of an antigen/antibody (Ag/Ab) combination assay to screen for HIV infection, as the first step. The use of this more advanced technology (fourth generation) provides improved detection of acute HIV-1 infection because antigen/antibody combination assays not only detect established infection in those who have seroconverted, but can also diagnose HIV infection prior to seroconversion by detecting p24 antigen. Fourth generation assays detect acute HIV infections, on average, five to seven days earlier than the third generation, antibody-only assays.
Second, substituting the HIV-1/HIV-2 differentiation assay for the Western blot in the second step allows for correct identification of HIV-2 infection and earlier detection of HIV-1 infection, compared to the Western blot.
Third, the official addition of nucleic acid testing (NAT) is used to rule out acute HIV-1 infection, which is necessary because although HIV-1/HIV-2 differentiation assays can detect HIV infection on average a few days earlier than the Western blot, none of these can detect HIV infection prior to seroconversion.
There is ample evidence that the new algorithm has increased detection of acute HIV-1 infections, due to the use of Ag/Ab combination assays. This is important both for the patient, who can receive prompt treatment that improves health outcome, and also from a public health perspective, because it reduces disease transmission. Many laboratories now have access to a fourth generation assay, since they are offered by multiple vendors on a variety of automated platforms.
The data are not yet in as to whether the new algorithm has resulted in a significant increase in yield of HIV-2 diagnoses; this would provide critical information regarding prevalence and transmission of HIV-2 infections in the United States.
Challenges of the new algorithm
The new algorithm, however, has presented some real challenges for the laboratory. The biggest adjustment to adopting the new algorithm has been replacing the Western blot with an HIV-1/HIV-2 differentiation assay. The only assay with this capability until recently was the Multispot (Bio-Rad). However, the Multispot is no longer available and will be replaced with Bio-Rad’s Geenius. Although the Geenius is also a single use test (FDA-cleared) for confirming reactive HIV screen results and differentiating between HIV-1 and HIV-2 antibodies, it differs from the Multispot in a number of important aspects. The test uses either recombinant or synthetic peptides corresponding to four HIV-1 antigens, gp160, gp41, p31 and p24, and two corresponding to HIV-2 antigens, gp140 and gp36. There are eight possible interpretations based on the pattern observed. Performance characteristics are comparable to Multispot. Sensitivity is 100 percent for both assays, and specificity values are 99.1 percent and 96.3 percent for the Multispot and Geenius, respectively. The results can be read within 30 minutes and are interpreted using an automated cassette reader, therefore eliminating inter-observer subjectivity. The cassette system also allows for placement of a bar code label on each specimen, improving sample tracking. Additionally, because software is necessary for interpretation, the results are digitally captured, automatically recorded, and stored.
However, because the new HIV-1/HIV-2 differentiation assay requires an additional investment in the reader/software component, beyond the cost of the reagents, there is some concern that some small hospital laboratories will revert to sending out supplemental HIV testing to a reference laboratory. It should also be noted that, although adoption of the new algorithm has grown significantly, there is still substantial demand for Western blot testing. Importantly, when a third or fourth generation assay was used for screening, an indeterminate or negative Western blot should also be followed up with NAAT.
There is also much confusion regarding appropriate use of the fourth generation rapid HIV test. Although at first glance it would appear that this assay can be used in lieu of the laboratory based Ag/Ab combination assay and serve as the entry point into the algorithm, that is not the current CDC recommendation. Citing insufficient evidence for such an approach, the CDC suggests that a preliminary positive result obtained with any rapid test, including an antigen/antibody combination rapid test, must be followed up with a laboratory-based antigen/antibody combination assay.
Fifth generation testing
The horizon appears even more complicated now that the “fifth generation” HIV testing is available. This technology is currently offered only by one vendor, but it has the ability to differentiate between antigen, HIV-1 and HIV-2 antibody-positive specimens. While this simplifies the answer with regard to HIV infection status for the patient, there are no guidelines as to how to proceed with follow-up testing. For example, if the sample is positive for antigen only, then the logical follow-up would be to send out for NAT testing, as there is no reason to test with the supplemental HIV-1/HIV-2 differentiation assay that only detects antibodies. If the sample is positive for HIV-2 only, is it appropriate to follow up with the HIV-1/HIV-2 differentiation assay, because the fifth generation test is FDA-approved as a screen only and a supplemental test is needed? Fifth generation technology presents further complications to the algorithm and more complexity for the laboratory in terms of appropriate follow-up and interpretation for clinicians.
Last, one unintended consequence of the new algorithm is the effect on HIV surveillance programs. Ideally for the purpose of HIV surveillance, public health departments would like to have the final answer as to whether a patient has HIV-1, HIV-2, or acute HIV-1 infection, once the HIV testing algorithm is complete. The problem is that this is almost impossible because testing is almost always fragmented and different steps of the algorithm are performed in different laboratories. Often primary institution laboratories have the ability to perform the screening, even with a fourth generation Ag/Ab combination assay, but cannot complete the remainder of the algorithm. The sample is then sent to the reference laboratory, and that laboratory has to determine how to interpret the results without having the screen results. How to report a partial result and make it clear to the clinician that additional testing is needed and also satisfy public reporting needs is much more difficult in the context of the new algorithm, for both the primary and reference laboratory.
In summary, many technological advances have been made that importantly improve detection of HIV-2 and acute HIV-1 infections. These advances are beneficial for both the patient and society. Although most clinicians and laboratories are now familiar with and support the implementation of the algorithm, laboratories are challenged more than ever to provide appropriate test result interpretation and utilization as well as adequate public health reporting for HIV.
- "Laboratory Testing for the Diagnosis of HIV Infection: Updated Recommendations". BioScience.pk Digital Library Database. Centers for Disease Control and Prevention (CDC). Published June 27, 2014.
About the author: Patricia Slev, PhD, DABCC, is Associate Professor of Pathology (Clinical), University of Utah and Medical Director of the Serologic Hepatitis and Retrovirus Laboratory, Core Immunology Laboratory and Co-Director Microbial Immunology Laboratory, at ARUP. Board certified by the American Board of Clinical Chemistry, Dr. Slev’s research interests are immunogenetics and pathogen interactions, particularly HIV and viral hepatitis.
Source: Medical Laboratory Observer: The status of laboratory testing for the diagnosis of HIV infection
Description: As of 2010, an estimated 1.1 million persons in the United States were living with human immunodeficiency virus (HIV) infection, of whom an estimated 181,000 were unaware of their infection. Approximately 49,000 new HIV diagnoses are reported to CDC each year, and the estimated number of new infections has remained stable at approximately 50,000 annually from 2008 to 2010. As of 2009, an estimated 83 million adults aged 18 to 64 years reported they had been tested for HIV. Accurate laboratory diagnosis of HIV is essential to identify persons who could benefit from treatment, to reassure persons who are uninfected, and to reduce HIV transmission.
- File Name Laboratory Testing for the Diagnosis of HIV Infection: Updated Recommendations
- Year 2014
- Editor(s) Bernard M. Branson MD, S. Michele Owen PhD, Laura G. Wesolowski PhD, Berry Bennett MPH, Barbara G. Werner, PhD, Kelly E. Wroblewski MPH, Michael A. Pentella PhD
- Publisher Centers for Disease Control and Prevention (CDC)
- Size 1.31 MB
- File Format .pdf
Bioscience, Biotechnology, and Biochemistry is a monthly, peer-reviewed, scientific journal published by the Japan Society for Bioscience, Biotechnology and Agrochemistry, of which it is the official journal. It was established in 1924 as Bulletin of the Agricultural Chemical Society of Japan, which was renamed to Agriculture and Biological Chemistry in 1961. The journal took its current name in 1991.
The focus of Bioscience, Biotechnology, and Biochemistry is previously unpublished original research results on all topics and fields concerning bioscience, biotechnology, and biochemistry. In addition, articles cover basic and applied sciences regarding microorganisms, including systems supporting their production, and structure. Broad topical coverage includes organic chemistry, bioorganic chemistry, physical chemistry, analytical chemistry, enzymology, biopolymer science, microbiology (including virology), animal science, plant science, food science, and environmental science.
Research applications are directed toward human welfare in general. Hence applications are transferred to industries of fermentation, chemistry and biochemistry, medicines and pharmaceuticals, foods and feeds, and agriculture.
Abstracting and indexing
Bioscience, Biotechnology, and Biochemistry is indexed in the following databases.
- "Agricultural and Biological Chemistry". Literature / Source Database. European Virtual Institute for Speciation Analysis. Retrieved 2010-08-19.
- "Agricultural and Biological Chemistry". Library of Congress Online Catalog. Library of Congress. Retrieved 2010-08-19.
- "Bioscience, Biotechnology, and Biochemistry".Literature/Source database. European Virtual Institute for Speciation Analysis. Retrieved 2010-08-19.
- "An Introduction to the Japan Society for Bioscience, Biotechnology and Agrochemistry". Academy of Science, Fields of Research, Contributions. JSBBA. August 2010. Retrieved 2010-08-19.
Claim- Drinking a cold glass of water after a meal can harm you. The cold water will solidify the oily stuff that you have just consumed, which will line the intestines and lead to cancer.
Verdict- False. Even if you accepted these claims as truth, a statement such as "A cardiologist says if you forward this to 10 people..." should have set off any properly working bullshit meter with a host of bells and flashing red lights. When you drink cold water, it is entering a system that self regulates to keep its core temperature within about half a degree, or around 37 c (98.6 f). ( For those that are wondering, typical oral temperature readings should be slightly cooler at 36.8c (96.2f)). From the time the water first comes into contact with your body, the heat transfer will begin to warm it up, and it will equalize within a few minutes. As an added bonus, drinking a half liter of ice cold water will actually make your body burn around 17 Calories in order to keep its temperature constant. The meal that you just consumed will not be affected in any way, as it will still end up at around the same temperature right up until you... uh "drop it off at the pool", regardless if you decided to wash it down with coffee or ice water afterwards.
Clogged large intestines do not cause cancer, they are a sign of cancer. Cancer is an uncontrolled division of abnormal cells in a part of the body. One way to think of it is when your cells replicate, a small error suddenly occurs in the copy process. That error gets passed down to the next copy and the next copy and the next. Before you know it, that one erroneous cell is now 2, then 4, then 16, then 256... eventually replacing all the good cells with cheap knock offs, and before long you're shopping for replacement parts because the original one(s) can no longer function the way it was meant to. (Sorry for the bad analogy. I think I have been working on cars too much lately.) Don't worry too much if you're feeling a little clogged up though because there are many other reasons for blockage, and most can be solved with a little bit of fiber in your diet.
The heart attack information is reasonably accurate but a little incoherent. Jaw pain may be a symptom of a heart attack, but typically accompanying other symptoms. The American Heart Association's warning signs your ticker may be faulty include;
- Uncomfortable Pressure, a squeezing or pain in the middle of your chest lasting for more than a few minutes
- Mild to intense pain spreading to the shoulders, arms, or neck, or jaw.
- Chest discomfort, feeling light headed, fainting, sweating, nausea, shortness of breath. Anxiety, nervousness, cold or sweaty skin, irregular heart rate,
Not all of these signs will necessarily occur. If you have one or more of these signs it is recommended you seek medical attention immediately, or you're going to end up having a really bad time.
Learning the art of ECG interpretation requires intellect, commitment, effort and perhaps most importantly...an organized approach. I personally have spent thousands of hours (yes thousands) looking at 12-lead ECG tracings, studying ECGs for the cardiology boards, interpreting ECGs for direct patient care and developing the ECG tutorials and quizzes of LearnTheHeart.com.
I assume that most of you reading this blog do not have that much time...so let me share with you what I have discovered in my years teaching ECGs to make the process more simple and perhaps even enjoyable.
Read more: 10 Steps to Learn ECG Interpretation
How will samples required for PCR, ELISA, or other immunoassay applications affect which pipette should be used?
Some of these drugs, including the antibiotics ciprofloxacin and ceftriaxone, have been deemed essential by the World Health Organization for the treatment of infections. However, chemists in developing countries often do not have expensive instruments to determine whether a pill is genuine.
Now, a simple paper-based test may be the answer.
Instead of a $30,000 machine, a $1 paper card can test a drug in three minutes to determine whether the medication is inactive or of substandard quality. The tests come in 20-card packets.
Read more: Paper-based Test Identifies Bogus and Poor Quality Drugs
The findings suggest that secondary growths called metastases 'punch' their way through the walls of small blood vessels by targeting a molecule known as Death Receptor 6 (no, really, that's what it's called). This then sets off a self-destruct process in the blood vessels, allowing the cancer to spread.
According to the team from Goethe University Frankfurt and the Max Planck Institute in Germany, disabling Death Receptor 6 (DR6) may effectively block the spread of cancerous cells - so long as there aren't alternative ways for the cancer to access the bloodstream.
Approved in April 2016, the Epi proColon (Epigenomics AG) is the first blood-based colorectal screening test to get a thumbs-up from the US Food and Drug Administration (FDA).
This molecular test detects methylated Septin 9 DNA in plasma, which is increased in colorectal cancer and can be found in tumor DNA that has been shed into the bloodstream from both colon and rectal sites. This makes it a differential biomarker for the early detection of colorectal cancer, according to the manufacturer.
Available in Europe since 2012, it is also being marketed in other countries, including China.
Read more: Blood Test for Colorectal Cancer: The Last Resort?
They analysed 380 different samples from 106 women between the ages of 29 and 73. To study the impact of storage time, only samples from 50-year-old women were used in order to isolate the time effect. 108 different proteins were analysed. In addition to how long a sample had been frozen, the researchers also looked at what year the sample was taken and the age of the patient when the sample was taken.
‘We suspected that we’d find an influence from storage time, but we thought it would be much less’, says Professor Ulf Gyllensten. ‘It has now been demonstrated that storage time can be a factor at least as important as the age of the individual at sampling.’
Blood from biobanks has been used in research aimed at producing new drugs and testing new treatment methods. The results of this study are important for future drug research, but it is not possible or necessary, to repeat all previous biobank analyses.
Read more: New finding: Biobank storage time affects blood test results