Practical Session 3 – Group 3

Remember that active participation in a reasonable and constructive way during the practical sessions as well as during the lectures scores positively for your final mark.

Lorenzo's Oil (1992)

Lorenzo’s oil is a drama based on real events. It tells the story of Lorenzo Odone who was diagnosed at the age of 5 years (in 1983) a rare and incurable disease, adrenoleukodystrophy (ALD), which causes a degenerative neurological condition leading to death in few years. There was no known treatment at that moment for ALD. The disease results in progressive deafness, blindness and paralysis. Soon after the diagnosis, his parents, with no medical or biochemical background, began a long struggle against illness seeking a treatment to save his son. The film was directed by George Miller, starring Nick Nolte and Susan Sarandon, and was nominated for two Academy Awards: Best Actress in a Leading Role (Susan Sarandon) and Best Writing, Screenplay Written Directly for the Screen (George Miller and Nick Enright).

ALD (also known as X-ALD, X-linked Adrenoleukodystrophy, Adrenomyeloneuropathy, Siemerling-Creutzfeldt Disease or Bronze Schilder Disease) is an X-linked hereditary disease affecting 1 in 20,000 males. It is caused by a deficiency of the protein ALD (ABCD1) whose function is to transport very long chain fatty acids (VLCFA) to the peroxisome for beta-oxidation. The lack of ABCD1 causes an accumulation of VLCFA in different tissues throughout the body, which produces an intense demyelination, leading to the development of severe neurological abnormalities and impaired vision, hearing and motor skills, leading to premature death.

The information about the disease is introduced gradually throughout the film, which contains many dramatic scenes; one of them being the moment in which Dr. Nikolais (Dr. Moser in real life) informs Lorenzo’s parents that the disease is hereditary and transmitted by the mother. The type of inheritance can be seen in the following schematic representation:

Super Size Me (2004)

Super Size Me is a documentary in which Morgan Spurlock investigates the effects of fast food in his own body, eating exclusively at McDonald's 3 times a day during one month. Throughout the experiment, he goes several times to different medical specialists to follow his evolution in terms of weight gain, changes in blood pressure and biochemical analyses. The results are surprising and interesting...

Obesity has become one of the leading causes of death and disability, threatening many of the health gains achieved during the last decades. Despite the alarm raised, the pandemic continues to grow without signs of abatement. The latest prevalence figures in the United States show that more than two thirds of Americans are overweight (68.5%) and 1 in 3 are obese (35.7%). Europe, in general, and Spain, in particular, follow the same trends observed in the USA. The prevalence of obesity in the Spanish adult population over 18 years, according to the results of the ENRICA study, is estimated to be 22.9% globally, being higher in males with 24.4% than in females with 21.4%. In the following video, several interesting numbers about the "weight of the world" are shown:

Practical session 2 - Group 2

BODY COMPOSITION WORKSHOP

Obesity is a public health problem due to its impact on morbidity and mortality, the reduction of quality of life and the health care costs. Data from the ENRICA study published in 2012 indicate that the prevalence of obesity in the adult population in Spain is 22.9% (24.4% in men and 21.4% in women). According to the World Health Organization (WHO), in 2008 approximately 1.5 billion of adults (ages 20 or +) worldwide were overweight with 500 million of them being obese:

An accurate and precise classification of overweight and obesity is required, since the consequences of overweight and obesity are more than mere aesthetic problems due to their high impact on health. Normal weight, overweight and obesity can be defined by the body mass index (BMI) and by the percentage of body fat.

Body mass index

Obesity is defined as an excess of adiposity that presents a risk to health. BMI is used in the clinical practice to evaluate the ponderal categories of the patients. The BMI (kg/m2) is calculated as a person's weight (kg) divided by the square of his/her height in metres (m). The WHO Expert Committee proposed the following BMI cutoff values for the classification of adult ponderal categories:

BMI is the most frequently used diagnostic tool for the classification of obesity, because it is an easy and reproducible measurement. In spite of its wide use for the assessment of overweight and obesity, BMI is not an accurate measurement of body fat; for example, individuals of high muscle mass will exhibit higher BMI and older adults will tend to have more body fat than younger adults for a same BMI due to skeletal muscle mass loss.

Body fat percentage

Overweight and obesity can be also assessed by using the percentage of body fat (i.e. total fat mass divided by total body mass). There is a sexual dimorphism in the percentage of body fat, with women generally having a higher percentage of body fat than men because of gender-specific fat depots in mammary glands and the gluteo-femoral region. A healthy range of body fat for women is 20-30%, whereas for men it is 10-20%. Gender-specific cutoff points for the classification of ponderal categories according to the percentage of body fat are shown below:

Practical exercise

Mary is a 25-year-old woman that practices sport daily with a BMI=26 kg/m2 and a percentage of body fat of 21%, and John is a 31-year-old man that works in an office, with a sedentary life and a BMI=26 kg/m2 and a percentage of body fat of 26%. What is their ponderal category?












Response: According to their BMI, Mary and John should be classified as overweight; however, according to their percentage of body fat (a better surrogate measurement of adiposity), Mary would be classified as normal weight, whereas John would be classified as obese. 

1. You will need to know the cutoff values for the classification of an individual as normal weight, overweight or obese according to the BMI and the percentage of body fat. There are gender-specific differences for the percentage of body fat due to the higher accumulation of fat in the mammary glands and gluteo-femoral region in women.
2. Several methods for the evaluation of body composition can be used, such as plicometry, electric bioimpedance, hydrodensitometry, air displacement plethysmography (Bod-Pod), dual energy X-ray absorptiometry (DEXA), magnetic resonance imaging and echography, among others.
3. Visceral or android obesity is associated with higher cardiovascular risk, metabolic alterations and an increase in morbi-mortality compared with subcutaneous or gynoid obesity. An easy way for the evaluation of visceral obesity in the clinical practice is the measurement of the waist circumference (cm) or the waist-to-hip ratio (WHR). You will need to know the gender-specific cutoff points of waist circumference and WHR associated with increased and substantially increased cardiometabolic risk.

PHYSICAL ACTIVITY WORKSHOP

Physical activity is defined as any body movement produced by skeletal muscles that requires energy expenditure. Although physical inactivity has been identified as the fourth risk factor for global mortality, increasing levels of physical inactivity are seen worldwide. Furthermore, sedentarism is estimated to be an important cause for the development of different types of cancers, diabetes and cardiovascular diseases. In this sense, regular and adequate levels of physical activity help to maintain a healthy body as well as to be more likely to maintain its weight.

The term physical activity should not be mistaken with exercise. Exercise is a subcategory of physical activity that is planned, structured and repetitive. Physical activity includes sports, exercise and other activities such as playing, walking, gardening, briskly pushing a baby stroller, climbing the stairs, and dancing.

 

There are some types of physical activity especially beneficial: 

1. Aerobic activities make your heart beat faster. Aerobic activities can be moderate or vigorous in their intensity.
2. Muscle-strengthening activities make your muscles stronger. These include activities like push-ups and lifting weights.
3. Bone-strengthening activities promotes bone growth and strength. These activities, like jumping, are especially important for children.
4. Balance and stretching activities enhance physical stability and flexibility. Examples are dancing, yoga or martial arts.

1. Total energy expenditure is the energy required by the organism daily and it is determined by the sum of several components: basal metabolism rate, diet-induced thermogenesis and physical activity, among others.

 

2. Physical activity represents the thermic effect of any body movement produced by skeletal muscles that requires energy expenditure. A great variability inter- and intra-individual is shown. In active individuals, the energy required for physical activity corresponds to one to two times that of the basal energy expenditure while in sedentary individuals it can represent less than half.

3. Sedentarism or physical inactivity comes up as the disease of the modern society, being identified as the fourth leading risk factor for global mortality. Sedentarism substantially increases the probability of developing obesity, cardiovascular diseases, diabetes or certain cancers.

4. Sedentarism has been positively correlated with chronic low-grade inflammation associated with obesity.

5. Different dimensions are used to describe physical activity:

• Frequency: sessions or days per week.
• Intensity: amount of effort required for the activity: low, moderate or vigorous.
• Duration: length of session or accumulated length of physical activity during a week.
• Type: other info about the nature of the activity.

6. American Heart Association recommendations for healthy adults aged 18 to 65 years:

• At least 30 minutes of moderate-intensity aerobic activity at least 5 days per week for a total of 150 minutes

      OR

• At least 25 minutes of vigorous aerobic activity at least 3 days per week for a total of 75 minutes; or a combination of the two

      AND

• Moderate to high intensity muscle-strengthening activity at least 2 or more days per week for additional health benefits.

7. The Metabolic Equivalent of Task (MET) corresponds to a physiological measure expressing the energy cost of physical activities. MET is defined as the amount of oxygen consumed while sitting at rest and is equal to 3,5 ml O2 per kg body weight per minute.

8. Two principal methods of assessing physical activity levels are described:

• Subjective methods, depending on our own perception. They are predominantly used for measurements in populations, e.g., questionnaires of physical activity, diaries, logs or recall surveys.

• The objective methods often rely on solid data or observations. These methods are predominantly used for measurements in individuals, e.g., pedometers, heart-rate telemeters, accelerometers, electronic motion sensors, calorimetry, doubly labelled water as well as direct observation.

What do the sedentarism and hibernation have in common?

Basal metabolic rate consists in the amount of energy expended daily by humans and other animals at rest. It corresponds to the minimal quantity of energy required to maintain vital physiological functions such as corporal temperature, respiration, circulation or the functioning of different organs such as liver, kidneys or brain.

Basal metabolic rate is lower in sedentary lifestyle people compared to that of active individuals. In the same way, under hibernation conditions metabolic activity declines precipitously to roughly 5% of the non-hibernating basal metabolic rate.

Practical Session 1 - Group 1

We have used the first part of the session to explain in great detail what we expect from you in the team work (which is mandatory) as well in the individual essay (which is optional) of our subject. Subsequently, we have shown a film ideally suited to discuss topics related to research ranging from the relevance of the scientific method to the intricacies of ethics.

“Something the Lord Made”

The movie “Something the Lord Made” is based on the verifiable facts of the clinical and experimental work that led to the first-ever surgical intervention with therapeutical purposes on a child suffering from Tetralogy of Fallot (to see the main features of Fallot's tetralogy, please, refer to the Keys of the Practical Session in the post corresponding to Group 2).
The following video outlines in a schematic way the main alterations of this pathology and how they are being surgically repaired nowadays. 

For those of you interested in learning more about how the operation is performed at present go to the explanations and video provided in the link corresponding to Practical Session 1 - Group 3 under the subheading surgical treatment of Tetralogy of Fallot).

Blalock and Taussig published in 1945 the positive results of their first 3 interventions on children with Tetralogy of Fallot in JAMA, one of the most prestigious medical journals.

In spite of the key contributions of Vivien Thomas in the research leading to the development of the surgical technique (subsequently termed the “Blalock-Taussig shunt”), his name does not appear among the authors of the original article. This fact was emphasized some years ago in a comment published in the same journal referring to the Blalock, Taussig & Thomas collaboration as an excellent example of translational research and the impact it exerted on the development of medicine. 

What do the human heart and a super tanker have in common?

Facts:

Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times.

Your body has about 5.6 liters of blood, which circulates through the body 3 times every minute. In one day, the blood travels a total of 19,000 km (12,000 miles) — that's around 4 times the distance across the US from coast to coast.

The heart pumps about 1 million barrels of blood during an average lifetime—that's enough to fill more than a couple of modern super tankers. 
 

Practical Session 1 - Group 3

We have devoted part of the 4-hour session to explaining in more detail what we expect from you in the team work (which is mandatory) as well in the individual essay (which is optional) of our subject.

"Something the Lord Made"

The movie "Something the Lord Made" traces the work of Alfred Blalock and Vivien Thomas in the 1930s at Vanderbilt University and their subsequent move in the 1940s to Johns Hopkins where together with Helen Taussig they carried out pioneering work in establishing a surgical treatment for Tetralogy of Fallot (TOF), a congenital heart malformation also known as Blue Baby Syndrome (to see the main features of Fallot's tetralogy, please, refer to the Keys of the Practical Session in the post corresponding to Group 2). The dramatization of the lifelong partnership between Blalock and Thomas allows to get insight into the way in which research and experimental approaches are used to tackle clinical challenges.

Surgical treatment of Tetralogy of Fallot

Due to the progressive improvement in cardiovascular surgery taken place over the past decades, the "Blalock-Taussig shunt" procedure is no longer used nowadays for the surgical repair of TOF. 
 

The following video shows the preparations for surgery and explains the surgical repairs that are performed today to treat this congenital heart malformation. 

"Well done"

Your are encouraged to actively participate during the practical sessions as well as during the lectures. Those of you that have replied to the questions formulated, shared their opinions and contributed to discussions by explaining their views and perspectives in a reasoned and constructive way have already started to score positively. Well done!!! Continue like this!!! We look forward for the rest to also join the vivid discussions!

Practical Session 1 - Group 2

We have already started the practical sessions in Room 2.

The first part of the 4-hour session has been devoted to explaining in more detail what we expect from you in the team work so that you are able to plan ahead and prepare yourself in advance.

“Something the Lord Made”

The film “Something the Lord Made” is based on true facts that transformed the medical practice of the past surgery in the fields of traumatic shock as well as in the treatment of Tetralogy of Fallot (TOF). Alfred Blalock, Helen Taussig and Vivien Thomas defied the rules of their time to launch an unprecedented surgical technique on patients with TOF, also called “blue babies” due to the cyanosis produced by this congenital heart defect.  

The operation involved the joining of the subclavian artery to the pulmonary artery. After meeting with Taussig, Blalock and Thomas developed an experimental model in dogs that resembled the pathophysiological conditions of the babies with TOF. This allowed them to subsequently experiment in the animal model a surgical approach to alleviate the suffering and secure death of children with TOF by performing a subclavian-to-pulmonary anastomosis. 

Taken from Warner Bros – HBO® VIDEO

Tetralogy of Fallot classically involves 4 anatomical abnormalities of the heart:

1. Overriding aorta
The degree to which the aorta is attached to the right ventricle is referred to as its degree of "override." The aortic root can be displaced toward the front or directly above the septal defect, but it is always abnormally located to the right of the root of the pulmonary artery.

2. Ventricular septal defect

A hole or communication between the two ventricles of the heart leads to a low oxygenation due to the mixing of oxygenated and deoxygenated blood. Usually, the defect is centered around the superior part of the ventricular septum and in the majority of cases consists in a single and large septal defect.

3. Pulmonary stenosis

The narrowing of the right ventricular outflow tract can be caused by valvular or infundibular stenosis. The degree of stenosis varies between individuals with TOF, and is the primary determinant of symptoms and severity.

4. Right ventricular hyperthrophy

As a compensatory mechanism the right ventricular wall increases in size to overcome the increased obstruction to the outflow posed by the pulmonary stenosis.

Active participation during the practical sessions as well as during the lectures scores positively. Those students that have replied to the questions formulated, shared their opinions and contributed to discussions by explaining their views and perspectives in a reasoned and constructive way have started to earn points for their final mark. Well done!!! Continue like this!!! The rest is also encouraged to participate!