Dengue infection - mechanisms, epidemiology, pathogenesis, diagnosis and management !

DENGUE:

"Dengue is the leading mosquito-borne viral illness infecting humans !"

Dengue is caused by infection with any of the four dengue virus serotypes. This review highlights the mechanisms underlying the clinical course of a dengue infection, which can range from mild febrile illness through to hemorrhagic fever and circulatory shock. It also outlines the epidemiology, pathogenesis, diagnosis and management of dengue infection.

Key phases of dengue infection

Dengue is a mosquito-borne disease caused by infection with dengue virus (DENV). Clinically, the disease can range from a mild febrile illness (previously called dengue fever) through to dengue with warning signs and severe dengue, which includes what were previously called dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).

 

DENVs belong to the genus Flavivirus of the Flaviviridae family. The four serotypes are enveloped, spherical viral particles with a diameter of approximately 500 Å20. The genome of each serotype comprises approximately 11 kb of positive-sense, single-stranded RNA that encodes ten proteins. The three structural proteins encoded by the genome are the membrane (M) protein, envelope (E) protein and capsid (C) protein; the non-structural (NS) proteins are NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5.

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Mechanism how SARS-CoV-2 causes COVID-19 progression !

COVID-19:

"The viral receptor on human cells plays a critical role in disease progression !"

Viruses enter cells and initiate infection by binding to their cognate cell surface receptors. The expression and distribution of viral entry receptors therefore regulates their tropism, determining the tissues that are infected and thus disease pathogenesis. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third human coronavirus known to co-opt the peptidase angiotensin-converting enzyme 2 (ACE2) for cell entry. The interaction between SARS-CoV-2 and ACE2 is critical to determining both tissue tropism and progression from early SARS-CoV-2 infection to severe coronavirus disease 2019 (COVID-19). Understanding the cellular basis of SARS-CoV-2 infection could reveal treatments that prevent the development of severe disease, and thus reduce mortality.

Key phases of disease progression

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to angiotensin-converting enzyme 2 (ACE2). Initial infection of cells in the upper respiratory tract may be asymptomatic, but these patients can still transmit the virus. For those who develop symptoms, up to 90% will have pneumonitis, caused by infection of cells in the lower respiratory tract. Some of these patients will progress to severe disease, with disruption of the epithelial-endothelial barrier, and multi-organ involvement.

 

As with all coronaviruses, SARS-CoV-2 cell entry is dependent on its 180-kDa spike (S) protein, which mediates two essential events: binding to ACE2 by the amino-terminal region, and fusion of viral and cellular membranes through the carboxyl-terminal region. Infection of lung cells requires host proteolytic activation of spike at a polybasic furin cleavage site. To date, this cleavage site is found in all spike proteins from clinical SARS-CoV-2 isolates, as well as some other highly pathogenic viruses (e.g., avian influenza A), but it is absent from SARS-CoV and is likely to have been acquired by recombination between coronaviruses in bats. Cleavage by the furin protease therefore expands SARS-CoV-2 cell tropism and may have facilitated transmission from bats to humans. Membrane fusion also requires cleavage by additional proteases, particularly transmembrane protease serine 2 (TMPRSS2), a host cell surface protease that cleaves spike shortly after binding ACE2. SARS-CoV-2 tropism is therefore dependent on expression of cellular proteases, as well as ACE2.

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Validation of Hematology Analyzers

Perhaps the most common laboratory procedure performed for hospital patients and outpatients is complete blood count (CBC) or CBC with differential. CBC serves as a screening and diagnostic test for a wide range of conditions and diseases as well as a monitoring tool for treatment and disease status. Given its foundational nature and despite its relative simplicity, the veracity of this basic blood testing is essential. Therefore, thorough validation testing on all new hematology analyzers must be performed to ensure patient safety.

It is reasonable to assume that a newly acquired piece of diagnostic equipment would run as intended, as manufacturers perform their own validation testing to prove intended use and to fulfill regulatory requirements prior to launching a product in the market. However, the ultimate responsibility of verifying instrument performance specifications and characteristics prior to the patient testing falls to the end-user laboratory.

Read more: Validation of Hematology Analyzers

Source: MedLabMag

Sensation of Touch Restored After More Than a Decade of Paralysis

Surgeons have restored the sensation of touch to a paralyzed man using a robotic arm connected to electrodes in his brain.

Twelve years ago a promising science student, Nathan Copeland, was involved in a car accident that left him paralyzed from the neck down. He went from being an active 18-year old to being quadriplegic. He was unable to feel anything from the chest down and could not move his lower arms and legs, so needed assistance with all his daily activities.

Read more: Sensation of Touch Restored After More Than a Decade of Paralysis

Source: NewsMedical

A Lab Manager's Guide to Getting Ahead

Being motivated and showing resourcefulness are what separate a star from the pack

Hard Work, Resourcefulness, and Great Mentors Required

When Lydia Coleman was 25 years old and worked as a staff member in a laboratory, before a surveyor’s visit she asked her then-boss whether managers had done anything in advance to prepare for the survey and had thought about what kinds of questions might arise. Coleman’s boss immediately realized that her employee’s questions showed initiative and enthusiasm for making the workplace run more smoothly, and she expressed her opinion of what a good idea that was. Six years later, Coleman had showed so much enterprise and learned enough to apply for and land a laboratory supervisor’s position, and for the past 35 years she has been either a manager or a director in the health care laboratory industry.

Read more: A Lab Manager's Guide to Getting Ahead

Source: LabManager

Why Does Alcohol Burn When You Drink It?

Anyone who's ever taken a shot of hard liquor can tell you: it burns on the way down. But it's not the alcohol itself that's burning your throat. Instead, the ethanol in the liquid is making your throat's VR1 heat receptors more sensitive, prompting them to perceive your own body temperature as hot. (Of course, this doesn't mean you should do shot after shot without fear of consequences.) Learn more about the science of alcohol with the videos below.

Here's Why Taking A Shot Of Tequila Burns Your Throat

Read more: Why Does Alcohol Burn When You Drink It?

Why Does Alcohol Burn When You Drink It? from SciShow

Source: curiosity

Watch Video: Biomedical Video: Why Does Alcohol Burn When You Drink It?

'Tracking Bugs' Reveal Secret of Cancer Cell Metabolism

One of the hallmarks of cancer is a change in cellular metabolism, a series of chemical reactions so fundamental to life that their alteration makes cancer cells seem creepily malevolent.

Healthy cells take in blood sugar (glucose molecules), which they break down to extract energy. This happens in two phases—one phase that takes place in the cytoplasm and a subsequent phase that occurs inside cellular compartments called mitochondria.

Cancer cells are thought to mostly skip the mitochondrial phase, compensating for the energy they forgo by revving up the first phase and breaking down glucose rapidly to secrete large quantities of lactate—a form of partially digested glucose that has long been regarded as a "waste product.

Read more: 'Tracking Bugs' Reveal Secret of Cancer Cell Metabolism

Metabolism is nothing if not complicated. Some of the major metabolic pathways are shown in this
metro-style map.

Source: phys.org

Streamlining the E.coli Genetic Code

Scientists design a bacterial genome with only 57 codons.

The genetic code normally contains 64 codons, but researchers from Harvard University and their colleagues have designed an Escherichia coli genome with only 57 codons, replacing the others wholesale. In a paper published today (August 18) in Science, the team describes the computer-generated genome and reports on the first phases of its synthesis in the lab.

“We create something that really pushes the limit of genomes,” study coauthor Nili Ostrov, a postdoc in George Church’s lab at Harvard, told The Scientist. “The idea is that this is completely new, and we’re trying to see if it’s viable.”

In the planned 57-codon E. coli genome, each of the seven deleted codons is exchanged for a synonymous one.

Read more: Streamlining the E.coli Genetic Code

SCIENCE, CHRIS BICKEL

Source: the-scientist

Most Aggressive Form of Prostate Cancer on the Rise

A new analysis suggests infrequent screening has resulted in an increase in the number of men diagnosed with the metastatic form of the disease.

For decades, experts have said the diagnostic used to screen patients for prostate cancer is too unreliable to use routinely because it produces high rates of false positives and often results in additional unnecessary and invasive tests, as well as overtreatment. However, a new study suggests efforts to limit the use of the prostate-specific antigen (PSA) test may be partially responsible for a rise in incidences of the most aggressive form of the disease.

Read more: Most Aggressive Form of Prostate Cancer on the Rise

Source: newsweek

Pregnancy Rates Higher for Women Who Have Had Tonsils, Appendix Removed

New study has uncovered a surprising association, finding that the surgical removal of the appendix or tonsils in younger age may increase a woman's chance of pregnancy.

Study co-author Sami Shimi, clinical senior lecturer in the School of Medicine at the University of Dundee, United Kingdom, and colleagues say their findings - published in Fertility and Sterility - should ease concerns that such procedures may reduce a woman's fertility.

The surgical removal of the tonsils, known as a tonsillectomy, is normally carried out as a result of frequent infection or inflammation of the tonsils (tonsillitis) or sleep-disordered breathing.

Surgical removal of the appendix, called an appendectomy, is normally the first-line treatment when the organ becomes infected or swollen - a condition known as appendicitis.

Read more: Pregnancy Rates Higher for Women Who Have Had Tonsils, Appendix Removed

Women who underwent a tonsillectomy or appendectomy when younger
were found to have higher pregnancy rates in a new study.

Source: medicalnewstoday

Science Behind Power Naps

With a very busy schedule and too much on our plate, we are not getting enough sleep nowadays. Sleep deprivation is very bad for the health and is giving rise to a number of diseases nowadays. Diseases like heart problems, fluctuations in sugar levels, high and low blood pressures and thyroid issues have become very common in sleep deprived individuals. This is where power naps can help.

When you sleep during the day between 1 PM and 4 PM for a period lasting between ten to thirty minutes, it is known as a power nap. If you sleep longer than thirty minutes, you might develop sleep inertia, a groggy feeling. You should also not sleep later than 4 PM as then you will find it difficult to sleep at night.

Read more: Science Behind Power Naps

Source: boldsky

Biomedical Laboratory Automation

Improve safety and efficiency in various types of clinical laboratories with Thermo Scientific™ TCAutomation™ Laboratory Automation Solutions. This expandable and scalable, fully-featured laboratory automation solution allows labor-intensive tasks in pre- and post-analytical phases of sample management to be automated in different combinations. Depending on the floor plan and efiiciency requirements, the TCAutomation™ systems can be expanded step-by-step.

TCAutomation™ systems throughput can range from 250 up to 1000 tubes per hour. Because solutions are modular, they are easy to expand. Automating can be started from a certain function and built up towards total laboratory automation. Samples are transported in the system within dual-lane conveyors in a multitube carrier which accommodates several tube sizes. The carrier includes an embedded microchip, based on RFID technology, making sample identification fast and reliable, and enabling excellent real-time sample tracking possibilities.

Read more: Biomedical Laboratory Automation

Download: Thermo Scientific TCAutomation Laboratory Automation Solution

Source: ThermoFisherScientific

A Laboratory for Empowerment

Though women earn 50 percent of degrees in science and engineering, they only represent 27 percent of the workforce in those fields. The UCSD Guardian investigates women’s representation in STEM at UCSD, as well as the steps the university is taking to increase their presence.

Seventy-seven cents to every man’s dollar. It’s a statistic often thrown around when discussing the oppression of women in the United States, but less often understood. The number does not come from comparing one male engineer’s salary to that of a female engineer’s. Instead, 77 cents to every one male-earned dollar is a statistic that compares the total income generated by men in the U.S. to the total income generated by American women. It’s a statistic that reveals that, on average, women are employed in lower-paying careers than men are. It’s not that female engineers are being paid 23 percent less than their male counterparts. It’s that there aren’t as many female engineers as male engineers to begin with; considering that, according to Payscale.com, the top 14 paying majors in the U.S. are in science, technology, engineering and math, this is a huge missed opportunity.

This is where STEM comes in. It’s a little acronym that represents a big conversation in today’s society. According to the U.S. Department of Commerce, in 2011, women held nearly half the jobs in the U.S. economy, but filled less than a quarter of the country’s STEM-related positions. Although women today have far more opportunities in academia than in the past, there are still far more men occupying STEM-related jobs than women. According to a 2013 study compiled by the National Girls Collaborative Project, while women are earning 50 percent of bachelor’s degrees in science and engineering, only 27 percent of the science and engineering workforce is made up of women. With nearly half of science and engineering bachelor’s degrees going to women, one would expect women to be equally represented in the workforce, making these statistics surprising.

Read more: A Laboratory for Empowerment

Source: Illustration by Alex Liang

Human sperm created from mature skin cells for infertility solution

Scientists in Spain say they have created human sperm from skin cells, which could eventually lead to a treatment for infertility.

The researchers said they were working to find a solution for the roughly 15 per cent of couples worldwide who are unable to have children and whose only option is to use donated gametes (sperm or eggs).

"What to do when someone who wants to have a child lacks gametes?" asked Dr Carlos Simon, scientific director of the Valencian Infertility Institute, Spain's first medical institution fully dedicated to assisted reproduction.

"This is the problem we want to address: to be able to create gametes in people who do not have them."

The result of their research, which was carried out with Stanford University in the United States, was published on Tuesday in Scientific Reports, the online journal of Nature.

Read more: Human sperm created from mature skin cells for infertility solution

Infertile sperm cells were created by adding genes to skin cells

Source: ABC News Breakfast

Obesity, stress and even cellphone use can influence men's ability to conceive

Certain lifestyle factors are linked to higher rates of damage in the genetic material in men’s sperm. This could affect men’s ability to conceive as well as the genes they pass on to their children.

According to researchers, the damage may stem from factors such as obesity, stress and even cellphone use.

Semen analysis usually looks at the numbers and the condition of whole sperm. But the authors of a small study in Poland believe the degree of breakage, or fragmentation, in DNA strands in the sperm might be a better indicator of fertility. DNA carries the cell’s genetic information and hereditary characteristics.

Men with fragmentation have lower odds of conceiving naturally and through such procedures as in vitro fertilization, the scientists write in the International Journal of Impotence Research.

Researchers have noticed before that lifestyle factors can influence the level of sperm DNA fragmentation, said Ricardo P. Bertolla of Sao Paulo Federal University in Brazil, who was not part of the new study.

Read more: Obesity, stress and even cellphone use can influence men's ability to conceive

In a new study, older men and those with higher work stress had more fragmentation of the DNA in
their sperm, which might affect their ability to conceive as well as the genes they pass on to their children.

Source: De Agostini/Getty Images