Podcast 017: Medical Research With Julia Chapman

Fake medicine is based on hogwash and wizardry, while real medicine is based on evidence and clinical trials.

Without the guidance of data, patient management is in confusion! No one really knows what to do! That makes medical research integral to accurate diagnosis and treatment.

In this episode, Julia talks about life as a medical researcher, how research applies to medical doctors and the challenges that research involves.

Podcast

About the guest speaker

Julia Chapman has worked at the Woolcock Institute since 2008 across a range of industry sponsored and investigator driven sleep and respiratory clinical trials. She recently completed her PhD which focussed on the treatment of daytime sleepiness in OSA with wakefulness promoters modafinil and armodafinil, including the longest randomised controlled trial of either of these drugs in OSA.

Julia left school thinking that she would one day be a professor of languages, but after studying pharmacology at the University of Sydney, she found that science was her passion. For her initial PhD work on the use of modafinil in mild-moderate OSA patients not using other treatments, she was awarded the Australasian Sleep Association’s New Investigator Award in 2013. She was awarded a postdoctoral research fellowship from NeuroSleep under the supervision of A/Prof Nat Marshall and Prof Ron Grunstein, who together are part of a team planning to establish a Sleep Clinical Research Network in Sydney and surrounding areas. She is now working on establishing research into the combined effects of shift work and OSA, as well as research in insomnia and chronic fatigue syndrome.

Music credits

Opening and closing themes by Lily Chen.

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Croup

Croup is formally titled acute laryngotracheobronchitis, but that’s a less catchy name.

It’s a viral upper respiratory tract infection that affects the larynx and trachea. It primarily occurs in children under 5 years old.

Symptoms

Croup attacks kids, so the acronym for symptoms must be in the appropriate theme.

CHILD

  • Coryzal prodrome
  • Hoarse voice
  • Inspiratory stridor
  • Like a barking seal cough
  • Difficulty breathing

Management

  • Single-dose corticosteroids of any of the following:
    • Dexamethasone orally
    • Prednis(ol)one orally
    • Nebulised budesonide

PLUS

  • Single-dose nebulised adrenaline if severe
    • Repeat after 30 minutes if no improvement
    • Observe for 4 hours after administration
    • ICU review if ineffective

References

  1. Croup. In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited (eTG November 2017 edition); 2017 Nov.

Podcast 016: Sports Medicine With Dr Bob Sallis

Sports is a unique field. It consists of grown adults or small children tossing equipment around according to made-up rules – and somehow having quite a lot of fun doing so.

That’s why sports medicine is a unique specialty. It deals with the afflictions of active people, often involving acute treatment at the moment of injury, not just chronic overuse.

In this episode, Dr Bob talks about sports medicine, his impactful work and the value of exercise.

Podcast

About the guest speaker

Dr Bob Sallis, M.D., FACSM, serves as the chairman for the Exercise is Medicine initiative and previously served as president (2007-08) of the American College of Sports Medicine (ACSM). Dr Bob received his Bachelor of Science degree from the U.S. Air Force Academy and his medical degree from Texas A&M University. He completed his residency in family medicine at Kaiser Permanente Medical Center in Fontana, Calif., where he served as chief resident. He has served as the head team physician at Pomona College since 1988, and holds a Certificate of Added Qualifications in sports medicine.

Dr Bob lectures and publishes extensively in the area of sports medicine and serves as chairman of the Science Advisory Committee to Governor Schwarzenegger’s Council on Physical Fitness and Sports. He received the 2008 Community Leadership Award from the President’s Council on Physical Fitness and Sports, and the 2009 Leonardo da Vinci award for international leadership in sports medicine from the Italian Federation of Sports Medicine. Dr Bob currently serves as editor-in-chief of ACSM’s clinical journal, Current Sports Medicine Reports.

Music credits

Opening and closing themes by Jim Cook’s computer, an Artificial Intelligence project by the Techlab.

The Function Of Testes

Initiation

The hypothalamus releases GnRH.

This stimulates the anterior pituitary gland to release FSH and LH, which act on the testes.

Production

FSH triggers spermatogenesis from Sertoli cells.

LH triggers testosterone production from Leydig cells.

Reduction

To control things for homeostasis, Sertoli cells release inhibin to dampen the release of FSH and LH from the anterior pituitary gland.

Testosterone gives negative feedback to the anterior pituitary gland and the hypothalamus.

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References

  1. Boundless Biology. (n.d.). Hormonal Control of Human Reproduction. [online] Available at: https://courses.lumenlearning.com/boundless-biology/chapter/hormonal-control-of-human-reproduction/ [Accessed 4 Mar. 2018].

Aromatase Inhibitors

Breast cancer can be oestrogen-sensitive, so a treatment target for such types is to inhibit oestrogen.

In premenopausal women, selective oestrogen receptor modulators, more conveniently called SERMs, include tamoxifen. This particular medication acts as an oestrogen receptor antagonist at the breast but an oestrogen receptor agonist at the uterus, which is why it minority increases the risk of endometrial cancer.

In postmenopausal women, aromatase inhibitors are an option. These interrupt the production of oestrogen by suppressing the action of the enzyme aromatase. Anastrazole and letrozole are the names to know here; they’re non-steroidal, reversible binders of aromatase from the third generation of aromatase inhibitors.

Why are aromatase inhibitors less effective in premenopausal women? Premenopausal women have a large quantity of aromatase in the ovary. Note that ovarian aromatase is sensitive to changes in the gonadotropin LH, which is produced by the pituitary gland. If aromatase is suppressed with an aromatase inhibitor, gonadotropins increase in response, according to the usual feedback pattern, which stimulates more ovarian aromatase. This makes aromatase inhibitors less proficient at inhibiting oestrogen production in the ovary in such a group.

References

  1. Fabian, C. J. (2007). The what, why and how of aromatase inhibitors: hormonal agents for treatment and prevention of breast cancer. International Journal of Clinical Practice, 61(12), 2051–2063. http://doi.org/10.1111/j.1742-1241.2007.01587.x

Podcast 015: Cardiology With Dr Chris Semsarian

Without the heart, there is no mindless muscle bag to pump blood all around the body. That would, unfortunately, lead to death.

Fortunately, cardiology exists to cure, palliate and address issues of this important organ!

In this episode, Professor Chris talks about his work as a specialist cardiologist, why he campaigned for public defibrillators and the crucial contribution of being passionate about your work.

Podcast

About the guest speaker

Dr Chris Semsarian is a cardiologist and professor with a specific research focus in the genetic basis of cardiovascular disease. He trained at the University of Sydney, Royal Prince Alfred Hospital and Harvard Medical School.

Professor Chris was awarded a Member in the General Division of the Order of Australia (AM) on January 26, 2017 for significant service to medicine in the field of cardiology as a clinician, administrator and educator and to the community. He has a large number of other letters behind his name too: MBBS PhD MPH FAHMS FRACP FRCPA FCSANZ FAHA FHRS.

Professor Chris has published over 200 peer-reviewed scientific publications, in the highest-ranking cardiovascular and general medical journals. A focus area of his research is in the investigation and prevention of sudden cardiac death in the young, particularly amongst children and young adults. He has been the primary supervisor of over 30 PhD, honours and medical honours students since 2003 and led major community programs in the area of prevention of sudden death.

Music credits

Opening and closing themes by Lily Chen.

Treatment Options For Hyperkalaemia

If hyperkalaemia is indeed real and not caused by haemolysis or a bad sample, treatment can be appropriate. It’s urgent if there are ECG changes.

  • Calcium gluconate
    • Stops membrane depolarisation
    • Does not reduce the serum potassium level
  • Sodium bicarbonate IV
    • To treat metabolic acidosis, which can be a potential underlying cause
      • Potassium moves out of cells because it exchanges with hydrogen ions
  • Insulin and glucose IV
    • Use short-acting insulin
    • To promote uptake of potassium into cells
    • Effective in kidney failure
  • Polystyrene resin orally
    • Removes potassium from bowel lumen by exchanging it for sodium or calcium
    • Comes in sodium or calcium varieties, called Resonium
      • Sodium type adds to sodium load in body
      • Calcium type avoids this but is unsuitable in hypercalcaemia
  • Dialysis
    • Last resort if extreme hyperkalaemia and nothing else works

Of course, the underlying cause should be treated; if it’s hypoaldosteronism, such as from adrenal insufficiency, corticosteroids should be given. If it’s volume depletion, that should be corrected. If the hyperkalaemia is caused by a medication, that medication should be ceased.

References

  1. Electrolyte abnormalities. In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited (eTG November 2017 edition); 2017 Nov.
  2. acutecaretesting.org. (2013). On the relationship between potassium and acid-base balance. [online] Available at: https://acutecaretesting.org/en/journal-scans/on-the-relationship-between-potassium-and-acid-base-balance [Accessed 17 Feb. 2018].