Odds ratios are best described as the odds of an event in one group divided by the odds of the event in another. They form an alternative to the relative risk in case-control studies and are close to the relative risk when events are rare. The odds are the number of the event divided by the number without the event, which is less intuitive than the risk, which is the number with the event divided by the total. Odds ratios are therefore less intuitive than relative risks. Logistic regression analysis outputs variable coefficients which are the log of the odds ratio.

MMR vaccine is a live vaccine. It contains measles, mumps and rubella. These vaccines should be avoided during chemotherapy and for 6 months after.

Pulmonary surfactant is a lipoprotein complex that is responsible for preventing the collapse of alveoli and increasing lung compliance.It is produced in the endoplasmic reticulum and secreted from the lamellar bodies of type 2 pneumocytes.Surfactant is essential for reducing surface tension at the air-water interface in the alveoli, thus preventing the collapse of alveoli during expiration. It is composed of dipalmitoyl phosphatidylcholine (DPPC), which is a phospholipid.In fetal development, production of surfactant begins around 26 weeks of gestation and reaches mature levels by 35 weeks.The deficiency of surfactant can result in neonatal respiratory distress syndrome or hyaline membrane disease, particularly in premature new-born babies.

The thyroid gland is one of the first endocrine glands to develop, and is formed from the endoderm of the epithelial tissue of the primitive pharynx. The mature gland is functionally made up of follicles with colloid which contain the pro hormone thyroglobulin. Thyroid hormone is synthesised at a cellular level and is stored as thyroglobulin, before its release as thyroid hormone, a major modulator of metabolism. In between the follicular cells are parafollicular, or C-cells which secrete parathyroid hormone or calcitonin which are responsible for calcium regulation in the body.

Coarctation of the aorta is one of the serious forms of congenital heart diseases Occurring in about 1 in 2,500 births. It is characterized by a congenitally narrowed proximal thoracic aorta. Coarctation can occur in isolation but can accompany other cardiac lesions, including a bicuspid aortic valve in 70% of the cases and berry aneurysms in 10% of the cases. Coarctation of the aorta is commonly found in association with Turner’s syndrome, Edward’s syndrome, and Patau syndrome.

CF is inherited in an autosomal recessive manner.This means that to have CF, a person must have a mutation in both copies of the CFTR gene in each cell. People with CF inherit one mutated copy of the gene from each parent, who is referred to as a carrier.CF carriers can pass their copy of the CFTR gene mutation to their children. Each time two CF carriers have a child together, the chances are: 25 percent (1 in 4) the child will have CF50 percent (1 in 2) the child will be a carrier but will not have CF25 percent (1 in 4) the child will not be a carrier of the gene and will not have CFThis male’s parents are obligate carrier because he has a sibling with CFSo the chances he is a carrier too are 2 in 3The risk of having an affected child is the chance of both himself and his partner being carriers: (2/3 x 1/25 = 2/75) x 1/4 = 1/150.

Scurvy is a condition caused by a dietary deficiency of vitamin C, also known as ascorbic acid. Humans are unable to synthesize vitamin C, therefore the quantity of it that the body needs has to come from the diet. The presence of an adequate quantity of vitamin C is required for normal collagen synthesis. In scurvy bleeding tendency is due to capillary fragility and not coagulation defects, therefore blood tests are normal.

This is probably a case of protein-induced allergic proctitis, due to dietary protein transmitted through the mother to the breast-fed child. The mother should go on a milk-free and soya-free diet but continue to breast-feed.

The age of the patient and the presence of immature white blood cells are suggestive of leukaemia. Hodgkin’s disease is unlikely in this age group and it usually presents with lymphadenopathy. In HIV, immature white blood cells are not present in the blood.

A bone age study helps doctors estimate the maturity of a child’s skeletal system. It’s usually done by taking a single X-ray of the left wrist, hand, and fingers. It is a safe and painless procedure that uses a small amount of radiation. The bones on the X-ray image are compared with X-rays images in a standard atlas of bone development, which is based on data from large numbers of other kids of the same gender and age. The bone age is measured in years.

Infection of chickenpox in the first half of pregnancy can result in congenital varicella syndrome. It presents as cerebral, cortical and cerebellar hypoplasia with convulsions and rudimentary digits. Prevention is by administering varicella vaccine, even before pregnancy. Varicella immunoglobulin is administered to pregnant women who are exposed to infection. Infection during pregnancy is treated with acyclovir.

Point mutations are the type of mutations in which only a single nucleotide of the DNA is either deleted, substituted or a new single nucleotide is inserted into the DNA, causing alterations in the original normal DNA sequencing. The examples of point mutations include hemochromatosis, sickle cell disease, and Tay-Sach’s disease. Huntington’s disease is a trinucleotide repeat disorder. Down’s syndrome is characterized by an extra copy of chromosome 21, while Klinefelter syndrome is marked by an extra X chromosome. Fragile X syndrome is also a trinucleotide repeat disorder.

18-month-old milestonesSocial and EmotionalLikes to hand things to others as play May have temper tantrums May be afraid of strangers Shows affection to familiar people Plays simple pretend, such as feeding a doll May cling to caregivers in new situations Points to show others something interesting Explores alone but with parent close by Language/CommunicationSays several single words Says and shakes head noť Points to show someone what he wants Cognitive (learning, thinking, problem-solving)Knows what ordinary things are for; for example, telephone, brush, spoon Points to get the attention of others Shows interest in a doll or stuffed animal by pretending to feed Points to one body part Scribbles on his own Can follow 1-step verbal commands without any gestures; for example, sits when you say sit downť Movement/Physical DevelopmentWalks alone May walk up steps and run Pulls toys while walking Can help undress herself Drinks from a cup Eats with a spoon

Because the initial chest X-ray returned an anomaly, a skeletal survey is the best option. Also known as a bone survey, the skeletal survey is a series of X-rays that will help analyse the structure of all the bones in the body. Because the child is not very active yet presents with bruising, the child protection register should also be checked but only after a skeletal survey has been conducted.

Undescended testis (UDT) is a common abnormality, affecting about 1/20 males at birth. Half of these have delayed testicular descent, with the testis in the scrotum by 10-12 weeks after term. Beyond this spontaneous descent is rare. Current treatment recommendations are that UDT beyond 3 months need surgery between 6-12 months of age. Some children have scrotal testes in infancy but develop UDT later in childhood because the spermatic cord does not elongate with age, leaving the testis behind as the scrotum moves further from the groin. The maldescended testis suffers heat stress when not at the lower scrotal temperature (33 degrees Celsius), interfering with testicular physiology and development of germ cells into spermatogonia. Recent evidence suggests orchidopexy between 6-12 months improves germ cell development, with early reports of improved fertility, but no evidence yet for changes in malignancy prognosis.Hypospadias is also a common abnormality in new-born males, affecting about 1/150 boys. Androgens control masculinization of the genital tubercle into penis between 8-12 weeks’ gestation, with tabularization of the urethra from the perineum to the tip of the glans. If this process is disrupted hypospadias occurs, with a variable proximal urethral meatus, failed ventral preputial development producing a dorsal hood, and discrepancy in the ventral versus dorsal penile length, causing a ventral bend in the penis, known as chordee. Surgery to correct hypospadias is recommended between 6-18 months.

Pulmonary surfactant is a mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space.

This clinical presentation is highly suggestive of choking. According to the BLS algorithm, the next step in managing a case of choking in a conscious child with an ineffective cough is five back blows.Other options:- Adrenaline intramuscularly: The history is similar to anaphylaxis, but the absence of a rash or oedema and the acute onset make choking more likely in this situation. Thus, adrenaline will not be of use in this patient.- CPR at a ratio of 15:2: Since the child is conscious, it is not advised. If the child were unconscious, you would commence basic life support.- Five abdominal thrusts: In the given scenario, the child is an infant. Abdominal thrusts are avoided in infants due to the risk of intra-abdominal injury.

Mild learning disabilities indicates an IQ = 50-70, or mental age of 9-12 years ˘ Moderate learning disabilities indicates an IQ = 35-49, or mental age of 6-9 years ˘ Severe learning disabilities indicates an IQ = 20-34, or mental age of 3-6 years ˘ Profound learning disabilities indicates an IQ = 20, or mental age of less than 3 years ˘ Average IQ is 100. The arbitrary cut-off to indicate learning disabilities is 70.

Tooth extraction or any surgical procedure may introduce bacteria into the blood stream. The most commonly involved organisms include Staphylococcus aureus and Streptococcus viridans. Once in the blood, these organisms have a very high tendency of attaching to the walls of the heart and causing inflammation known as endocarditis.

Neurogenic shock is a devastating consequence of spinal cord injury (SCI), also known as vasogenic shock. Injury to the spinal cord results in sudden loss of sympathetic tone, which leads to the autonomic instability that is manifested in hypotension, bradyarrhythmia, and temperature dysregulation. Spinal cord injury is not to be confused with spinal shock, which is a reversible reduction in sensory and motor function following spinal cord injury. Neurogenic shock is associated with cervical and high thoracic spine injury. Early identification and aggressive management are vital in neurogenic shock to prevent secondary spinal injury.

Bilirubin encephalopathy (BE), also known as kernicterus is a preventable complication of neonatal jaundice. Bilirubin deposits in the basal ganglia, hippocampus, geniculate bodies and cranial nerve nuclei, exerting direct neurotoxic effects and causing mass-destruction of neurons by apoptosis and necrosis.The clinical features of this diagnosis have been well described and can be divided into 3 stages:Phase 1 (first few days of life): Decreased alertness, hypotonia, and poor feeding are the typical signs. Obviously, these are quite nonspecific and could easily be indicative of a multitude of neonatal abnormalities. A high index of suspicion of possible BIND at this stage that leads to prompt intervention can halt the progression of the illness, significantly minimizing long-term sequelae. Of note, a seizure is not typically associated with acute bilirubin encephalopathy.Phase 2 (variable onset and duration): Hypertonia of the extensor muscles is a typical sign. Patients present clinically with retrocollis (backward arching of the neck), opisthotonos (backward arching of the back), or both. Infants who progress to this phase develop long-term neurologic deficits. Phase 3 (infants aged >1 wk): Hypotonia is a typical sign.

Hyperkalaemia is not to evaluate or detect AKI but rather the result of it. If one of the rest of the options is present, then AKI would be suspected.

Answer: Acute Epstein Barr virus infectionThe Epstein-Barr virus is one of eight known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. Infection with Epstein-Barr virus (EBV) is common and usually occurs in childhood or early adulthood.EBV is the cause of infectious mononucleosis, an illness associated with symptoms and signs like:fever,fatigue,swollen tonsils,headache, andsweats,sore throat,swollen lymph nodes in the neck, andsometimes an enlarged spleen.Although EBV can cause mononucleosis, not everyone infected with the virus will get mononucleosis. White blood cells called B cells are the primary targets of EBV infection.Petechiae on the palate are characteristic of streptococcal pharyngitis but also can be seen in Epstein-Barr virus infection, Arcanobacterium haemolyticum pharyngitis, rubella, roseola, viral haemorrhagic fevers, thrombocytopenia, and palatal trauma.

The most probable diagnosis in this patient would be pulmonary stenosis. Pulmonary Stenosis:Pulmonary valve murmurs are heard in the upper left sternal edge, associated with a thrill but no desaturation in the absence of an additional shunt. The ECG changes suggest right ventricular hypertrophy. Pulmonary stenosis is often well tolerated in childhood unless severe. These should be monitored with serial echocardiography, and balloon pulmonary valvoplasty should be considered once the pressure gradient reaches 64 mmHg.Other options:- Atrial septal defect: While atrial septal defects are associated with right ventricular outflow tract murmurs, they would not cause a thrill.- Patent ductus arteriosus: PDA murmurs can be audible in the left upper sternal edge, but would normally be audible in the left infraclavicular area and be continuous rather than ejection systolic. This left to right shunt would not cause desaturation but does cause left-sided volume loading and hence left-sided ECG changes.- Tetralogy of Fallot: Ventricular septal defect, overriding aorta, subpulmonary stenosis, and right ventricular hypertrophy. This would often cause a ULSE murmur with a thrill and RVH on ECG. However, this degree of obstruction would cause shunting from right to left, and this child would be desaturated.- Ventricular septal defect: Isolated ventricular septal defects cause pansystolic murmurs at the left lower sternal edge. They would have left-sided ECG changes and normal saturations (in the absence of pulmonary hypertension).

Based on the findings presented, the sign elicited is Rovsing’s sign.Rovsing’s sign:It is a sign suggestive of appendicitis. A positive sign is determined when palpation in the left lower quadrant of a patient’s abdomen causes pain in the right lower quadrant.Other options:- Murphy’s sign is positive in gallbladder inflammation. With the upper border of the examiner’s hand in the right upper quadrant of the abdomen under the rib cage, the patient is asked to inhale. Inhalation causes the gallbladder to descend, which catches on the fingers, causing pain.- Cullen’s sign is suggestive of ectopic pregnancy or acute pancreatitis and describes the bruising around the umbilicus.- Tinel’s sign is positive in those with carpal tunnel syndrome. The examiner’s fingers tap the median nerve over the flexor retinaculum, which causes paraesthesia over the distribution of the median nerve.- Battles’ sign describes bruising behind the ear, suggesting a basal skull fracture of the posterior cranial fossa.

The clinical picture suggests that the child is severely dehydrated. IV fluid bolus then IV maintenance fluids is the correct option.

Live attenuated vaccines such as the MMR, should be avoided in HIV+ patients.

Infective endocarditis (IE) is caused by a bacterial, or fungal infection which damages the heart’s endothelium and can thus lead to changes in heart function, valve incompetencies, possible cardiac failure, as well other associated skin and organ changes. Organisms common in IE include Staphylococcus aureus and Streptococcus viridians. The HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella species) are common in neonates. The Duke criteria uses 2 major, or 1 major and 3 minor criteria, or 5 minor criteria to diagnose infective endocarditis. Major criteria include:- a positive blood culture and evidence of endocardial involvement. Minor criteria include: – evidence of predisposition (a heart condition of injection drug use)- a fever- vascular phenomena such as Janeway lesions- immunologic phenomena such as Osler’s nodes and Roth’s spots; and- microbiological or serological evidence of active infection.

Cystic fibrosis is an autosomal recessive inherited disorder that affects the lungs or the pancreas. In the case of an affected child whose parents do not have the disorder but carry one copy of the mutated gene, each sibling has a 50% chance of being a carrier of the disease. They can inherit one copy of the gene from each parent. There is a 25 % chance that the child may inherit both mutated genes and be homozygous for the trait.

If the 95% confidence interval contains zero (more precisely, the parameter value specified in the null hypothesis), then the effect will not be significant at the 0.05 level.If the 95% CI for the DIFFERENCE between the 2 groups contains the value 0, this means that the p-value will be greater than 0.05. Conversely, if the 95% CI does not contain the value 0, then the p-value will be strictly less than 0.05. The same applies when comparing groups using a ratio, such as an odds ratio or risk ratio. When using a RATIO instead of a DIFFERENCE, the situation of no difference between the 2 groups will be indicated by a value of 1 instead of 0. If the ratio equals to 1, the 2 groups are equal. Hence, if the 95% CI of the ratio contains the value 1, the p-value will be greater than 0.05. Alternatively, if the 95% CI does not contain the value 1, the p-value is strictly less than 0.05.