Day: April 26, 2023

Categories : GastrointestinalTags :

Not Your ‘Average’ Gut: Study Reveals Great Variation in Gastrointestinal Systems

On By ModernMedia
Source: CC0

There is a great deal of variation in the anatomy of the gastrointestinal system, with pronounced differences possible between healthy individuals, according to surprising new research published in PeerJ. Differences between males and females were also uncovered.

The finding has implications for understanding the role that the digestive tract’s anatomy can play in affecting human health, as well as providing potential insights into medical diagnoses and the microbial ecosystem of the gut.

“There was research more than a century ago that found variability in the relative lengths of human intestines, but this area has largely been ignored since then,” says Amanda Hale, study co-first author and a PhD candidate at North Carolina State University. “When we began exploring this issue, we were astonished at the extent of the variability we found.”

“If you’re talking to four different people, odds are good that all of them have different guts, in terms of the relative sizes of the organs that make up that system,” says Erin McKenney, corresponding author and an assistant professor of applied ecology at NC State. “For example, the cecum is an organ that’s found at the nexus of the large and small intestine. One person may have a cecum that is only a few centimeters long, while another may have a cecum the size of a coin purse. And we found similar variability for many digestive organs.”

In another striking example, the researchers found that women tend to have longer small intestines than men.

“Because having a longer small intestine helps you extract nutrients from your diet, this finding supports the canalisation hypothesis, which posits that women are better able to survive during periods of stress,” says Hale.

“Given that there is more variation in human gut anatomy than we thought, this could inform our understanding of what is driving a range of health-related issues and how we treat them,” says McKenney. “Basically, now that we know this variability exists, it raises a number of research questions that need to be explored.”

For this study, the researchers measured the digestive organs of 45 people who donated their remains to the Anatomical Gifts Program at the Duke University School of Medicine.

In addition to shedding light on the unexpected variability in human anatomy, this project also led to rediscovering the importance of teaching anatomical variation to medical students.

“It’s particularly important in medical training, because if students are only learning about a ‘normal’ or ‘average’ anatomy, that means they are not going to be familiar with the scope of human variation,” says Roxanne Larsen, co-author of the paper and an associate professor of veterinary and biomedical sciences at the University of Minnesota. “It’s increasingly clear that the medical field is moving toward individualized medicine to improve patient outcomes and overall health and well-being. Garnering experience in understanding anatomical variation can play a critical role in helping future doctors understand the importance of individualised medicine.”

“We’re excited about this discovery and future directions for the work,” McKenney says. “It underscores just how little we know about our own bodies.”

Source: North Carolina State University

Categories : Metabolic DisordersTags :

The Body’s Safety Valve Against Insulin Shock

On By ModernMedia
Novolog insulin pen. Photo by Dennis Klicker on Unsplash

Insulin is an important treatment for people with type 1 or 2 diabetes, but excessive insulin can cause hypoglycaemia, leading to convulsions, coma and possibly death – a collection of conditions that defines insulin shock.

In a new study published in Cell Metabolism, a team of scientists at the University of California San Diego School of Medicine, with colleagues elsewhere, describe a key component in the mechanism that regulates against excessive insulin.

“Although insulin is one of the most essential hormones, whose insufficiency can result in death, too much insulin can also be deadly,” said senior study author Professor Michael Karin, PhD, at UC San Diego School of Medicine.

In the new study, Karin, first author Li Gu, PhD, a postdoctoral scholar in Karin’s lab, and colleagues describe “the body’s natural defence or safety valve” that reduces the risk of insulin shock.

That valve is a metabolic enzyme called fructose-1,6-bisphosphate phosphatase or FBP1, which acts to control gluconeogenesis, a process in which the liver synthesises glucose, during sleep and secretes it to maintain steady supply of glucose in the bloodstream.

Some antidiabetic drugs, such as metformin, inhibit gluconeogenesis but without apparent ill effect. Children born with a rare, genetic disorder in which they do not produce sufficient FBP1 can also remain healthy and live long lives.

But in other cases, when the body is starved for glucose or carbohydrates, an FBP1 deficiency can result in severe hypoglycaemia, leading to convulsions, coma and possibly death.

Compounding and confounding the problem, FPB1 deficiency combined with glucose starvation produces adverse effects unrelated to gluconeogenesis, such as an enlarged, fatty liver, mild liver damage and elevated blood lipids or fats.

To better understand the roles of FBP1, researchers created a mouse model with liver specific FBP1 deficiency, accurately mimicking the human condition. Like FBP1-deficient children, the mice appeared normal and healthy until fasted, which quickly resulted in the severe hypoglycaemia and the liver abnormalities and hyperlipidaemia described above.

Gu and her colleagues discovered that FBP1 had multiple roles. Beyond playing a part in the conversion of fructose to glucose, FBP1 had a second non-enzymatic but critical function: It inhibited the protein kinase AKT, which is the primary conduit of insulin activity.

“Basically, FBP1 keeps AKT in check and guards against insulin hyper-responsiveness, hypoglycaemic shock and acute fatty liver disease,” said first author Gu.

Working with Yahui Zhu, a vising scientist from Chongqing University in China and second author of the study, Gu developed a peptide (a string of amino acids) derived from FBP1 that disrupted the association of FBP1 with AKT and another protein that inactivates AKT.

“This peptide works like an insulin mimetic, activating AKT,” said Karin. “When injected into mice that have been rendered insulin resistant, a highly common pre-diabetic condition, due to prolonged consumption of high-fat diet, the peptide (nicknamed E7) can reverse insulin resistance and restore normal glycaemic control.”

Karin said the researchers would like to further develop E7 as a clinically useful alternative to insulin “because we have every reason to believe that it is unlikely to cause insulin shock.”

Source: University of California – San Diego

Categories : Injury & Trauma NeurologyTags :

Up to Half of Concussions May Have Long-lasting Effects

On By ModernMedia
Photo by Tom Jur on Unsplash

Even mild concussion can cause long-lasting effects to the brain, according to a University of Cambridge analysis published in Brain. The study researchers showed that for almost a half of all people who receive a concussion, there are changes in how regions of the brain communicate with each other. This could potential cause long term symptoms such as fatigue and cognitive impairment.

Concussion, a mild traumatic brain injury, can occur as a result of a fall, a sports injury or from a cycling accident or car crash, for example. But despite the ‘mild’ label, it is commonly linked with persistent symptoms and incomplete recovery. Such symptoms include depression, cognitive impairment, headaches, and fatigue.

While some clinicians in recent studies predict that 9 out of 10 individuals who experience concussion will have a full recovery after six months, evidence is emerging that only a half achieve a full recovery. This means that a significant proportion of patients may not receive adequate post-injury care.

Predicting which patients will have a fast recovery and who will take longer to recover is challenging, however. At present, patients with suspected concussion will typically receive either a CT or MRI brain scan to look for structural problems, such as inflammation or bruising. Yet even if these scans show no obvious structural damage, a patient’s symptoms may still persist.

Dr Emmanuel Stamatakis from the Department of Clinical Neurosciences and Division of Anaesthesia at the University of Cambridge said: “Worldwide, we’re seeing an increase in the number of cases of mild traumatic brain injury, particularly from falls in our ageing population and rising numbers of road traffic collisions in low- and middle-income countries.

“At present, we have no clear way of working out which of these patients will have a speedy recovery and which will take longer, and the combination of over-optimistic and imprecise prognoses means that some patients risk not receiving adequate care for their symptoms.”

Dr Stamatakis and colleagues studied functional MRI (fMRI) brain scans taken from 108 patients with mild traumatic brain injury and compared them with scans from 76 healthy volunteers. Patients were also assessed for ongoing symptoms.

The patients and volunteers had been recruited to CENTER-TBI, a large European research project which aims to improve the care for patients with traumatic brain injury.

The team found that just under half (45%) were still showing symptoms resulting from their brain injury, with the most common being fatigue, poor concentration and headaches.

The researchers found that these patients had abnormalities in a region of the brain known as the thalamus, which integrates all sensory information and relays this information around the brain. Counter-intuitively, concussion was associated with increased connectivity between the thalamus and the rest of the brain – in other words, the thalamus was trying to communicate more as a result of the injury – and the greater this connectivity, the poorer the prognosis for the patient.

Rebecca Woodrow, a PhD student in the Department of Clinical Neuroscience and Hughes Hall, Cambridge, said: “Despite there being no obvious structural damage to the brain in routine scans, we saw clear evidence that the thalamus – the brain’s relay system – was hyperconnected. We might interpret this as the thalamus trying to over-compensate for any anticipated damage, and this appears to be at the root of some of the long-lasting symptoms that patients experience.”

Using positron emission tomography (PET) scans, the researchers were able to make associations with key neurotransmitters depending on which long-term symptoms a patient displayed. For example, patients experiencing cognitive problems such as memory difficulties showed increased connectivity between the thalamus and areas of the brain rich in the neurotransmitter noradrenaline; patients experiencing emotional symptoms, such as depression or irritability, showed greater connectivity with areas of the brain rich in serotonin.

Dr Stamatakis added: “We know that there already drugs that target these brain chemicals so our findings offer hope that in future, not only might we be able to predict a patient’s prognosis, but we may also be able to offer a treatment targeting their particular symptoms.”

Source: University of Cambridge

Categories : General Interest Medical IndustryTags :

Many Pilots Dodge Doctors to Keep Flying

On By ModernMedia
Photo by Daniel Eledut on Unsplash

A survey of military and paid civilian pilots has revealed that they may avoid seeking medical advice out of fear of losing certification to fly. Two-thirds of military and paid civilian pilots answered “yes” to at least one of four survey questions on reluctance to seek formal medical advice about health problems, reported William R. Hoffman, MD, who presented a poster at the American Academy of Neurology annual meeting.

Hoffman, a US Air Force employee, noted that both civilian and military pilots can be grounded if they have certain medical symptoms or diagnoses, with a range of negative repercussions for the pilot. As a result, pilots are disinclined to be truthful about their health if their employers or officials might find out.

In a previous survey of pilots led by Hoffman, more than three-quarters reported that they “felt worried about seeking medical care due to concern for their career or hobby.” The new survey probed this reluctance, with respondents asked whether they agreed or disagreed with the following:

  • Sought informal medical advice for fear of certificate loss
  • Flew despite experiencing a new symptom (physical or psychological) that warranted evaluation
  • Did not disclose prescription medication use
  • Misrepresented or withheld information on a written healthcare questionnaire for fear of certificate loss

Respondents to the web-based survey included 2383 nonprofessional civilian pilots, 1097 paid civilian pilots, and 261 military pilots.

Just over half of the unpaid civilian pilots denied ever hiding any of the four types of information. But that was true for only 33.6% of the paid civilian pilots and 32.2% of the military pilots.

Fortunately, among all respondents, only 6.8% said they had not disclosed prescription drug use as required, and just 16.8% acknowledged that they had kept new symptoms secret. But 45.7% acknowledged seeking informal advice in place of seeing a professional, and 26.8% said they had withheld or overtly misrepresented information on written forms. A few (2.2%) admitted to all four types of avoidance.

Female pilots reported slightly more avoidance of disclosure (62.0% of all female respondents vs 55.4% of men; P not reported). Younger pilots were also less open, especially those aged 25–40 (69.1% vs 40.7% in those older than 60). Union membership and active-duty military status were linked to high rates of avoidance (70.1% and 75.8%, respectively, vs 51.8% among non-unionised civilian and military reservist pilots).

Hoffman suggested that neurologists recognise that pilots may be shy about revealing their true health condition. “This might be mitigated through developing rapport with the pilot, asking questions about concerns related to their flying status, and clear communication about documentation and clinic course.”

Additionally, he recommended, “it is good technique to order only the necessary tests for all patients, to include pilots to avoid false positives.”

Despite this, medical professionals have an obligation to communicate a pilot’s health concerns to those responsible for evaluating fitness to fly.

Source: MedPage Today

Categories : General Interest NeurologyTags :

Introducing The Wits Journal of Neuroscience – Inaugural Issue

On By ModernMedia

Modern Media Publishing is pleased to announce the inaugural issue of the Wits Journal of Neuroscience*, a new academic journal aiming to connect those in the field of neuroscience and broaden its horizons in South Africa.

The journal is available online here, and will also have a print distribution.

The new publication will feature articles from clinician researchers in the fields of neurosurgery, neurology, ophthalmology and ears, nose and throat (ENT). The journal features original research and case reports and MMed articles selected by its distinguished editorial board. It also reports on local neuroscience news and events as well as international research highlights. Readers also get a peek behind the curtain at upcoming research.

Professor John R. Ouma, Head of Department of Neuroscience at Wits said, “The aim of this new journal is to fill a gap that has been existing, wherein there has not hitherto been a common platform for academicians and others interested in neurosciences to come together and share ideas as well as generate new science.

“This journal will be widely circulated within the Neuroscience community of this University and its associated hospitals, and then further afield to sister Universities, hospitals and entities to ensure that the ideas generated and expressed in it achieve the widest exposure and impact.

“We hope you enjoy it, both now, and in future editions.”

*The Wits Journal of Neuroscience is Produced and Distributed on behalf of the Wits Dept of Neuroscience by Modern Media Publishing (Pty) Ltd. They can be contacted on 011-326-4171 or by email on info@modernmedia.co.za