Research news in brief

Some facts about the Medevac Bill

Since the passing of the Medevac Bill last week, according to Guardian Australia, “all kinds of misleading claims about what this package does” have been made. The article laid some facts about the Bill:

1. Medical evacuations from Manus and Nauru can be refused by the Home Affairs Minister on the following grounds: if the Minister disagrees with the clinical assessment, the case would then be referred to an “Independent Health Advice Panel” as soon as is practical; if the Minister suspects the transfer of the person to Australia would be “prejudicial to security”, according to the Australian Security Intelligence Organisation, and that the threat “cannot be mitigated”; and if the Minister knows the transferee has a “substantial criminal record”.
2. A “substantial criminal record” is defined in this case as “if the person has been sentenced to death; life imprisonment; a term of imprisonment of 12 months or more; has been in prison for two or more terms where the total is 12 months or more; if the person has been acquitted of an offence on the grounds of unsoundness of mind or insanity, and as a result the person has been detained in a facility or institution; or the person has been found by a court to not be fit to plead in relation to an offence, and the court has nonetheless found that on the evidence available the person committed the offence, and as a result the person has been detained in a facility or institution”.
3. The Independent Health Advice Panel will be made up of the Commonwealth Chief Medical Officer (CMO), the Home Affairs Department’s CMO, and at least six others, including a nominee of the president of the Australian Medical Association, of the Royal Australian and New Zealand College of Psychiatrists and of the Royal Australasian College of Physicians, and an expert in paediatric health. None will be paid, to avoid conflicts of interest.
4. The new procedures only apply to the cohort of asylum seekers currently on Nauru and Manus Island, not to any new boat arrivals.
5. Transferees in Australia for medical treatment “must be kept in immigration detention while in Australia”, unless the Minister decides otherwise.
6. According to the Guardian article, “the architecture of offshore detention remains in place. Boat turn backs remain in place”.

“Cellular barcoding” reveals how breast cancer spreads

A cutting-edge technique called “cellular barcoding” has been used by researchers from the Walter and Eliza Hall Institute of Medical Research (WEHI) to tag, track and pinpoint cells responsible for the spread of breast cancer from the main tumour into the blood and other organs. The technique also revealed how chemotherapy temporarily shrinks the number of harmful cells, rather than eliminating them, explaining how the cancer could eventually relapse. Insights from the study, published in Nature Communications, could lead to new targeted treatments for breast cancer. Breast cancers consist of thousands of different cell variants with diverse characteristics that may or may not play a role in the metastasis of the cancer. This makes effective treatment a challenge because it is difficult to know which cells are responsible for driving the spread of cancer. The WEHI researchers said the ability to pinpoint the “clones” – subpopulations of cells arising from an original patient tumour – responsible for the spread of cancer was crucial for improving treatments. “Our study revealed that only a select few clones were actually responsible for the metastasis. The barcoding technique enabled us to identify the clones that were able to get into the blood stream and make their way into other organs where they would ‘seed’ new tumour growth.” The technique also allowed the researchers to see what was happening to the clones after chemotherapy was introduced. “We used the chemotherapy agent cisplatin to treat laboratory models developed using donated breast tumour tissue. While the treatment was able to shrink tumours and the size of individual clones, it did not kill them off completely. All the clones, including the nasty seeders, eventually grew again, accounting for cancer relapse.”

Penis development in womb requires more than testosterone

Proper development of the fetal penis requires not just testosterone from the testes, but a second hormone produced by other tissues, including the placenta, according to a study published in PLOS Biology. The results reveal a previously unknown pathway of masculinisation of the external genitals, and may explain why placental dysfunction is associated with disorders of male genital development. During development of the male fetus, the testes release testosterone, which is converted to 5α-dihydrotestosterone (DHT) by the genital tubercle, helping to ensure that this primordial structure develops into a penis, rather than into the female clitoris. Recently, penis development was shown to also depend on a second process, called the alternative or “backdoor” pathway, which also ends in the production of DHT but doesn’t depend on the production of testosterone by the testes. However, the details of this backdoor pathway, including the source of the DHT precursor, have been unclear. To learn more about this pathway, researchers used mass spectrometry to measure levels of different steroids in fetal plasma and tissue during the second trimester, when the most critical steps in penis development occur. They also analysed gene expression levels in various tissues of key enzymes known to be involved in hormone synthesis. They found that androsterone, a steroid from the backdoor pathway, which can be converted to DHT, was the principal androgen in the male fetal circulation, and that levels of both androsterone and testosterone were lower in the female fetal circulation. They also found that enzymes needed for the backdoor pathway were present primarily in non-gonadal tissue, including the liver and the placenta. Since androsterone can be made from progesterone, the authors suggested that placental progesterone or related compounds are the likely source of androsterone in the backdoor pathway. While it remains unclear why a sex difference in fetal androsterone levels exists, the researchers found high expression in the male genital tubercle of enzymes required to convert androsterone to DHT. The male genital tubercle appears, therefore, to be able to convert both testosterone and androsterone into DHT.

Treating insomnia improves back pain

A new systematic review and meta-analysis from the University of Sydney, published in Osteoarthritis and Cartilage, shows that treatment for insomnia can help to reduce back pain, further enforcing the complex link between sleep and pain. Chronic low back pain is the leading cause of disability worldwide, affecting an estimated 540 million people at any one time. More than 59% of affected patients also experience insomnia. The researchers analysed data from 24 randomised controlled clinical trials treating sleep disorders in more than 1550 people with osteoarthritis and back or neck pain. Results showed that in people with back pain, sleep interventions such as cognitive behavioural therapy and medication improved sleep by 33% and improved pain by 14% compared with control or placebo. Based on the study results, researchers say health professionals treating patients with back pain should be conscious of screening for insomnia and referring them for management. While low back pain improved with insomnia treatments, participants with knee osteoarthritis did not appear to experience major reductions in pain despite minor improvements in sleep. The researchers’ next step is to carry out studies on combined treatments. They are also exploring the effectiveness of a fully online cognitive behavioural therapy sleep treatment for people with low back pain and insomnia symptoms.