Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Potential early indicator of kidney injury identified

13.03.2013
A guidance cue that helps kidneys form may also be a red flag that they are in danger, researchers report

A guidance cue that helps kidneys form may also be a red flag that they are in danger, researchers report.

Acute kidney injury, a common and serious complication of hospitalization, is on the increase worldwide, affecting an estimated 6 percent of all hospitalized patients and 30-40 percent of adults and children having cardiopulmonary bypass surgery.

About 10-15 percent of acute injuries translate to chronic kidney damage or failure that may require dialysis or a kidney transplant, said Dr. Ganesan Ramesh, kidney pathologist in the Vascular Biology Center at the Medical College of Georgia at Georgia Regents University.

Now, animal and human studies have shown that within a few hours of injury, a significant amount of the protein semaphorin 3A is detectable in the urine, Ramesh and his colleagues report in the journal PLOS ONE.

"Semaphorin 3A appears to be a sensitive biomarker that we believe will give physicians an early and accurate heads-up that their patient's kidneys have been injured so that damage can be minimized and potentially reversed with rapid intervention," said Ramesh, the study's corresponding author.

The protein, which is not usually measurable in urine, was quickly detected in a group of 60 pediatric patients following cardiopulmonary bypass surgery at Cincinnati's Children's Hospital. High levels of the protein were about 90 percent accurate at identifying the 26 children with acute kidney injury. In those patients, urine levels were high within two hours, peaked at six hours and essentially normalized 12 hours after surgery.

Probably because of the kidney's significant reserve capacity, it's more like 48 hours before the current biomarker creatinine, a byproduct of muscle metabolism typically excreted by the kidneys, is elevated in the blood. By then, it's often too late for strategies such as massive fluid volumes, antibiotics and other interventions to yield significant improvement, he said

In the study group, creatinine levels were essentially the same in all 60 children for 24 hours. By 48 hours, levels were significantly elevated in the acute kidney injury group and stayed up for five days.

The researchers initially identified semaphorin 3A in an animal model of temporarily compromised oxygen levels, or ischemia, to the kidneys. When they eliminated the protein's expression in a mouse, it reduced ischemia-related kidney damage.

The hard-working, high-energy kidneys are particularly vulnerable to any decreases in the usual oxygen levels that may result from life-saving strategies such as cardiopulmonary bypass and mechanical ventilation, Ramesh said. Over the course of the day, the kidneys filter the body's total blood volume several times, resorbing needed components like nutrients and eliminating toxins, excess sodium and more. When they stop filtering properly, the body starts dumping both good and bad products into the urine.

Children with congenital heart defects who need multiple surgeries to repair their hearts may be at particular risk for acute kidney injury. In the study, children who developed the injury spent the longest time on bypass and in the hospital.

Many unknowns persist about semaphorin 3A including the role of the guidance cue in the healthy developed kidney and why it's levels shoot up then drop down so dramatically with injury. He notes that there is fairly significant cell turnover in the kidneys so it may have a role in regeneration. Ramesh has already worked with Japanese physicians to look at the levels in 350 older patients in intensive care for a variety of maladies. He's also working on an antibody that will screen specifically for semaphorin 3A.

The study was funded by the National Institutes of Health.

Toni Baker | EurekAlert!
Further information:
http://www.gru.edu

More articles from Health and Medicine:

nachricht Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin

nachricht Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>