A research team led by the University of Iowa has created the most detailed, three-dimensional rendering of a mammal lung…Amidst the extraordinarily dense network of pathways in a mammal lung is a common destination. There, any road leads to a cul-de-sac of sorts called the pulmonary acinus. This place looks like a bunch of grapes attached to a stem (acinus means ‘berry’ in Latin).
Scientists have struggled to understand more specifically what happens in this microscopic, labyrinthine intersection of alleys and dead ends. To find out, a research team led by the University of Iowa created the most detailed, three-dimensional rendering of the pulmonary acinus. The computerised model, derived from mice, faithfully mimics each twist and turn in this region, including the length, direction and angles of the respiratory branches that lead to the all-important air sacs called alveoli.
　
The model is important, because it can help scientists understand where and how lung diseases emerge as well as the role the pulmonary acinus plays in the delivery of drugs, such as those commonly administered with inhalers.
‘These methods allow us to understand where in the lung periphery disease begins and how it progresses,’ says Eric Hoffman, professor in the departments of radiology, medicine, and biomedical engineering at the UI and corresponding author on the paper. ‘How do gases and inhaled substances get there and do they accumulate in one or another acinus? How do they swirl around and clear out? We just don’t have a complete understanding how that happens.’
As an example, Hoffman said the model could be used to determine how smoking-induced emphysema originates. ‘It has been hypothesised recently that it begins with the loss of peripheral airways rather than the lung air sacs,’ he says, citing ongoing research by James Hogg at the University of British Columbia, who was not involved in this study. It also could shed light and lead to more effective treatment of chronic obstructive pulmonary disease, which causes irreversible damage to the lung, says Dragos Vasilescu, first author on the paper who based his thesis on the research while a graduate student at the UI.
For years, the best that lung anatomy pioneers such as study co-corresponding author Ewald Weibel, professor emeritus of anatomy at the University of Bern, could do to study specific areas of a lung was to make measurements in two dimensions or create 3D casts of a lung’s air spaces. The techniques, while giving the earliest insights into a lungs’s makeup and functioning, had their limitations. For one, they did not directly replicate a lung’s structure in real life, and they could not convey how various parts act together as a whole. Yet advances in imaging and computation have enabled researchers to more fully explore how gases and other inhaled substances act in the lung’s furthest recesses.
In this study, the team worked with 22 pulmonary acini culled from young and old mice. They then set to ‘reconstruct’ the acini based on micro computed tomography imaging of scanned lungs in mice and extracted from them. The extracted lungs were preserved in a way that kept the anatomy intact—including the tiny air spaces required for successful imaging. From that, the researchers were able to measure an acinus, estimate the number of acini for each mouse lung and even count the alveoli and measure their surface area.
The mouse lung, in its structure and function, is remarkably similar to the human lung. That means researchers can alter the genetics of a mouse and see how those changes affect the peripheral structure of the lung and its performance.
Already, the researchers found in the current study that mouse alveoli increase in number long past the two weeks that at least one previous study had indicated. Hoffman adds that a separate study is needed to determine whether humans, too, increase the number of air sacs past a certain, predetermined age.
The researchers next aim to use the model to more fully understand how gases interact with the bloodstream within the acini and the alveoli. University of Iowa

A fast, accurate diagnosis is essential for efficient treatment, especially in patients with complications. The Rapid Influenza Diagnostic Tests (RIDTs) for influenza detection have been developed to subtype the influenza virus, but rapid testing is no good unless it is accompanied by high levels of selectivity, specificity and accuracy. Over the course of a year, this study obtained over 1,000 nasal aspirate samples from patients with symptoms of influenza-like illness and evaluated by 2 types of RIDTs, Standard Diagnosis (SD) and QuickVue (QV) Rapid tests followed by real-time RT-PCR. The results showed that the SD rapid test appeared to be more sensitive than the QV test during high season activity, whereas the QV test was more sensitive during the period of low influenza virus activity. The conclusion was that due to persistent genetic drift of the influenza virus, the available RIDTs should be re-evaluated each year.

^{Makkoch J. et al. Clin. Lab. 2012; 58(9-10): 905-910. DOI: 10.7754/Clin.Lab.2011.111003}

Vitamin D, best known for its role in calcium uptake and bone density has also been shown to have beneficial effects on the immune system, with some studies demonstrating a correlation between higher vitamin D intake and a lower incidence of cancer, and that adequate vitamin D levels may also decrease the risk of autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. Now, a recent study, conducted by doctors across London hospitals and published in the Proceedings of the National Academy of Sciences, has shown that tuberculosis (TB) patients recovered more quickly when given both the vitamin and antibiotics. This idea is reminiscent of earlier times when TB patients, in the days before antibiotics, were prescribed sunbathing, which increases vitamin D production. This study found that recovery was almost two weeks faster when vitamin D was added to the treatment regime, with patients clearing the infection in 23 days on average, compared to 36 days for patients given antibiotics and a placebo. Vitamin D treatment will not replace antibiotics, but might well become a useful extra weapon, particularly with the increasing prevalence of drug-resistant TB. The vitamin seems to work by reducing the inflammatory response to the infection and helping the lungs to heal more quickly. If these lung cavities heal more quickly, patients are infectious for a shorter period of time and may also suffer less lung damage. Stronger evidence and trials to find the best dose and form of vitamin D will be needed before the treatment is put into widespread use.

http://www.pnas.org/

There’s a reason emergency personnel train for the aftermath of a dirty bomb or an explosion at a nuclear power plant. They’ll be faced with a deluge of urgent tasks, such as identifying who’s been irradiated, who has an injury-induced infection, and who’s suffering from both.
Unfortunately, there isn’t a quick way to screen for people exposed to dangerous levels of radiation. There also isn’t a quick way to distinguish between people suffering from radiation exposure versus an infection due to an injury or chemical exposure.
The most common way to measure exposure is a blood assay that tracks chromosomal changes. Another approach is to watch for the onset of physical symptoms. But these methods can take several days to provide results, which is far too late to identify people who’d benefit from immediate treatment.
A much faster way could be coming. Research conducted by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) could lead to a blood test that detects if a person has been exposed to radiation, measures their dose, and separates people suffering from inflammation injuries—all in a matter of hours.
The scientists identified eight DNA-repair genes in human blood whose expression responses change more than twofold soon after blood is exposed to radiation. They also learned how these genes respond when blood is exposed to inflammation stress, which can occur because of an injury or infection. Inflammation can mimic the effects of radiation and lead to false diagnoses.
The result is a panel of biochemical markers that can discriminate between blood samples exposed to radiation, inflammation, or both. The scientists believe these markers could be incorporated into a blood test that quickly triages people involved in radiation-related incidents.
‘In an emergency involving radiation exposure, it’s likely that only a small fraction of all possibly exposed people will be exposed to high doses that require immediate medical attention,’ says Andy Wyrobek of Berkeley Lab’s Life Sciences Division. ‘The goal is to quickly screen for these people so they can get treatment, and avoid overwhelming medical facilities with the larger number of people exposed to low levels of radiation with no immediate medical needs. Our research could lead to a blood test that enables this.’
Wyrobek conducted the research with fellow Berkeley Lab scientists Helen Budworth and Antoine Snijders, as well as several other scientists from Berkeley Lab and other institutions.
Because DNA is one of the major targets of radiation, the Berkeley Lab scientists began their research by focusing on 40 genes that regulate the expression of proteins that carry out DNA-repair tasks. They studied these genes in blood samples taken from healthy people before and after exposing the samples to 2 Gray of X-rays per year, which is about the radiation dose received by radiotherapy patients. They found twelve genes that underwent more than a twofold change in response after exposure. From these, they isolated eight genes that had no overlap between unirradiated and irradiated samples.
The scientists also treated the blood samples with a compound that mimics inflammatory stress. This enabled them to account for gene-expression responses that could be mistaken for signs of radiation exposure, but which are actually caused by injury or infection. In addition, they irradiated a portion of these samples to learn how the genes respond to both inflammation and radiation.
To validate their findings, the scientists analysed a separate dataset of blood samples that had also been irradiated. They found a close match between their own data and the independent dataset in how the eight genes respond after radiation exposure.
They also compared their findings to a large group of bone marrow transplant patients who received total-body radiation. Again, they found a close match between their data and the gene-expression responses of the patients after they received treatment.
More work is needed, but Wyrobek envisions a blood test using their biochemical markers could be administered via a handheld device similar to what diabetes patients use to check their blood sugar. The test could help emergency personnel quickly identify people exposed to high radiation doses who need immediate care, and people exposed to lower doses who only need long-term monitoring. Lawrence Berkeley National Laboratory

Everybody is talking about Internet addiction – many people spend hours online and immediately start feeling bad if they are unable to do so. Medically, this phenomenon has not yet been as clearly described as nicotine or alcohol dependency. But a study conducted by researchers from the University of Bonn and the Central Institute of Mental Health (ZI) in Mannheim now provides indications that there are molecular-genetic connections in Internet addiction, too.
‘It was shown that Internet addiction is not a figment of our imagination,’ says the lead author, Privatdozent Dr. Christian Montag from the Department for Differential and Biological Psychology at the University of Bonn. ‘Researchers and therapists are increasingly closing in on it.’ Over the past years, the Bonn researchers have interviewed a total of 843 people about their Internet habits. An analysis of the questionnaires shows that 132 men and women in this group exhibit problematic behaviour in how they handle the online medium; all their thoughts revolve around the Internet during the day, and they feel their wellbeing is severely impacted if they have to go without it.
The researchers from the University of Bonn and the Central Institute of Mental Health in Mannheim compared the genetic makeup of the problematic Internet users with that of healthy control individuals. This showed that the 132 subjects are more often carriers of a genetic variation that also plays a major role in nicotine addiction. ‘What we already know about the nicotinic acetylcholine receptor in the brain is that a mutation on the related gene promotes addictive behavior,’ explains Dr. Montag. Nicotine from tobacco fits – just like acetylcholine, which is produced by the body – like a key into this receptor. Both these neurotransmitters play a significant role in activating the brain’s reward system. ‘It seems that this connection is not only essential for nicotine addiction, but also for Internet addiction,’ reports the Bonn psychologist.
The actual mutation is on the CHRNA4 gene that changes the genetic makeup for the Alpha 4 subunit on the nicotinic acetylcholine receptor. ‘Within the group of subjects exhibiting problematic Internet behaviour this variant occurs more frequently – in particular, in women,’ says Dr. Montag. This finding will have to be validated further because numerous surveys have found that men are more prone to Internet addiction than women. The psychologist assumes, ‘The sex-specific genetic finding may result from a specific subgroup of Internet dependency, such as the use of social networks or such.’
Dr. Montag added that studies including more subjects are required to further analyse the connection between this mutation and Internet addiction. ‘But the current data already shows that there are clear indications for genetic causes of Internet addiction.’ He added that with the mutation, a biological marker had been found that would allow to characterise online addiction from a neuro-scientific angle. ‘If such connections are better understood, this will also result in important indications for better therapies,’ says Dr. Montag. University Bonn