The selection process is based on five requirements and essentially aims to select a random representative cohort through:1.Isolating a group for which there is a greater or lesser chance of detecting a possible difference between the treatments compared|2.Establishing a homogeneous group in order to reduce the variability of response, thus making statistical comparison more sensitive and decreasing the risk of bias due to the constitution of non-homogeneous groups|3.Obtaining representative samples of the affection studied|4.Defining the rules corresponding to realistic recruitment|5.Respecting ethical obligations.

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by intestinal hamartomatous polyps in association with a distinct pattern of skin and mucosal macular melanin deposition (freckles on the lips, face, palms and soles). Patients with Peutz-Jeghers syndrome have an estimated 15-fold increased risk of developing intestinal cancer compared to the general population.Management: conservative unless complications develop.

Crossover trials are characterized by the switching of study participants throughout the treatment groups, keeping a random order of switching. This randomization is important to determine any carry-over effect of different treatment modalities. The benefit of this study is the evaluation of the efficacy of various short-term treatment options for the relief of chronic conditions. The washout period is small in this type of study. Crossover studies are more efficient than the parallel studies, but they should be used according to the treatment options and outcomes.

The physical features and developmental delay are the key aspects in the given scenario. The child in question shows features of gross motor and social developmental delay and has physical features indicative of Prader-Willi syndrome (hypopigmentation, esotropia, disproportionately small hands and feet, loss of central muscle tone and undescended testes). Children with Prader-Willi syndrome can present with failure to thrive until ,12-18 months, at which point, hyperphagia and obesity become more prominent. Other options:- Although Klinefelter syndrome can present with delayed development, undescended/small testes and reduced muscle power, the presence of small hands/feet, hypopigmentation and failure to thrive are not characteristic features. – Marfan syndrome presents with different physical features (arachnodactyly, cardio-respiratory complications and skin changes, amongst others) than those associated with Prader-Willi syndrome. – DiGeorge can manifest with developmental delay, hypotonia and feeding difficulties. However, this clinical scenario does not report any of the typical facial features, hearing abnormalities or cardiac abnormalities that are typically caused by DiGeorge syndrome. – Russell-Silver syndrome can cause developmental abnormalities, poor muscle tone and power (poor head control and muscle function), feeding difficulties and poor growth during the post-natal period and infancy. However, characteristic facial (small, triangular face, blue sclerae) and skeletal abnormalities (limb asymmetry, finger abnormalities) are not present. Therefore, Prader-Willi syndrome is the most appropriate diagnosis for this patient.Note:Prader-Willi syndrome is an example of genetic imprinting where the phenotype depends on whether the deletion occurs on a gene inherited from the mother or father: In Prader-Willi syndrome, it is the paternal gene that is deleted from the long arm of chromosome 15, while in Angelman syndrome the maternal gene is deleted. Prader-Willi syndrome can occur due to the microdeletion of paternal 15q11-13 (70% of cases) maternal uniparental disomy of chromosome 15.

Infants exposed to maternal HIV and with positive results require immediate management with co-trimoxazole prophylaxis, regardless of their CD4 levels. Antiretroviral treatment is necessary as well but it could wait until further work-up is complete.

Measles and chickenpox are spread by droplets. Thus, patients should be isolated. Rheumatic fever and post-streptococcal glomerulonephritis are immune mediated diseases that don’t require isolation. Herpetic gingivostomatitis spreads by direct transmission of infected secretions to the stratified squamous epithelium. HSP is not an infectious disease.

The type of significance test used depends on whether the data is parametric (can be measured, usually normally distributed) or non-parametric.
Parametric tests:
Student’s t-test – paired or unpaired*
Pearson’s product-moment coefficient – correlation

Non-parametric tests:
Mann-Whitney U test – unpaired data
Wilcoxon signed-rank test – compares two sets of observations on a single sample
chi-squared test – used to compare proportions or percentages
Spearman, Kendall rank – correlation.

The outcome measured is not normally distributed, i.e. it is non-parametric. This excludes the Student’s t-tests. We are not comparing percentages/proportions so the chi-squared test is excluded. The Mann–Whitney U test is a nonparametric test of the null hypothesis that it is equally likely that a randomly selected value from one sample will be less than or greater than a randomly selected value from a second sample.
This test can be used to investigate whether two independent samples were selected from populations having the same distribution.

Among the options provided, the most characteristic finding that can be expected in his patient’s urine microscopy is RBC casts. Red cell casts are a characteristic feature of acute nephrotic syndrome. Other options:- Hyaline casts may be seen in normal urine, particularly after exercise. – Coarse granular casts occur in glomerular and tubular disease. – Tubular cell casts may be seen in patients with acute tubular necrosis. – The presence of 10 or more white blood cells/mm3 is abnormal and indicates an inflammatory reaction, most commonly due to infection.

Based on the clinical scenario, the most likely nerve injured in this case is the ulnar nerve.Ulnar Nerve:It arises from the medial cord of brachial plexus (C8, T1).It supplies motor fibres to the following structures:- Medial two lumbricals- Adductor pollicis- Interossei- Hypothenar muscles: abductor digiti minimi, flexor digiti minimiflexor carpi ulnarisIt carries sensation from the palmar and dorsal aspects of the medial 1 1/2 fingers.Patterns of damageIf the nerve is damaged at the wrist, the following features are observed:- Claw hand’: Hyperextension of the metacarpophalangeal joints and flexion at the distal and proximal interphalangeal joints of the 4th and 5th digits.- Wasting and paralysis of intrinsic hand muscles (except lateral two lumbricals)- Wasting and paralysis of hypothenar muscles- A sensory loss in the medial 1 1/2 fingers (palmar and dorsal aspects)If the nerve is damaged at the elbow or above the ulnar paradox is observed – the fourth and fifth fingers are simply paralyzed and claw hand is less severe.

Amniotic fluid is the protective liquid that surrounds the fetus in utero. It prevents the fetus from injury, protects the umbilical cord from compression, and provides necessary nutrients and a medium for growth and movement. Amniotic fluid originates from the maternal plasma initially, but by 16th week of gestation, fetal kidneys start making urine which contributes to further production of the amniotic fluid. Amniotic fluid contains a number of chemical substances including hormones, tumour markers, nutrients, electrolytes, and immunoglobulins. Main substances found in amniotic fluid include carbohydrates, proteins, lipids, lactoferrin, insulin-like growth factor, granulocyte colony-stimulating factor, erythropoietin, etc. Interleukin-1 is not a component of AF.

The clinical scenario provided is highly suggestive of third-degree burns (or full-thickness burns) that may have invaded the deeper levels up to dermis, evident from the insensate nature of the lesion.Degrees of Burns:- First degree burns are superficial second-degree burns.- Second-degree burns are just deeper than that of first-degree burns but vary enormously in other properties.- Third-degree burns are full-thickness burns which are leathery in consistency, and insensate. These burns do not heal on their own. The sensory neurons present in the skin at the deeper levels are destroyed completely and hence provide a paradoxical lack of pain.- Fourth-degree burns involving the subcutaneous tissues, tendons, and bones are very difficult to manage.Assessment of the extent of the burns for the treatment employs specialized charts, such as Lund and Browder charts and Wallace rule of nines.The Lund and Browder chart is, however, considered the most accurate.Wallace’s Rule of Nines can be used for children >16 years: – Head + neck = 9%- Each arm = 9%- Each anterior part of leg = 9%- Each posterior part of leg = 9%- Anterior chest = 9%- Posterior chest = 9%- Anterior abdomen = 9%- Posterior abdomen = 9%

In the first trimester of pregnancy, amniotic fluid is produced from maternal plasma where there is a rapid bi-directional diffusion across the foetal skin. At 10 weeks the volume is about 25ml. By 16th weeks of gestation the foetal kidneys make urine that contributes to the increasing volume of amniotic fluid, along with nasal secretions. At 20 weeks, the level is 400ml and increases to 800ml at 28weeks, after which it reduces to 600ml at term.

Milestones of 3 years old:Social and Emotional:Copies adults and friends Shows affection for friends without prompting Takes turns in games Shows concern for crying friend Understands the idea of “mine” and “his” or “hers” Shows a wide range of emotions Separates easily from mom and dad May get upset with major changes in routineDresses and undresses self Language/Communication:Follows instructions with 2 or 3 steps Can name most familiar things Understands words like “in,” “on,” and “under” Says first name, age, and sexNames a friend Says words like “I,” “me,” “we,” and “you” and some plurals (cars, dogs, cats) Talks well enough for strangers to understand most of the time Carries on a conversation using 2 to 3 sentences Cognitive (learning, thinking, problem-solving):Can work toys with buttons, levers, and moving parts Plays make-believe with dolls, animals, and people Does puzzles with 3 or 4 pieces Understands what “two” means Copies a circle with pencil or crayon Turns book pages one at a time Builds towers of more than 6 blocks Screws and unscrews jar lids or turns door handle Movement/Physical Development:Climbs well Runs easily Pedals a tricycle (3-wheel bike) Walks up and down stairs, one foot on each step

At least seven episodes in the previous year, five episodes in each of the previous two years, or three episodes in each of the previous three years are indications for tonsillectomy. Antibiotics should be administered in the conventional dosage for proved or suspected streptococcal episodes. For now the child should be treated on a case by case basis.

The azygos lobe is usually well seen on the chest radiograph, where it is limited by the azygos fissure, a fine, convex (relative to the mediastinum) line that crosses the apex of the right lung.

The pituitary gland synthesizes and releases various hormones that affect several organs throughout the body.The pituitary gland is entirely ectodermal in origin but is composed of 2 functionally distinct structures that differ in embryologic development and anatomy: the adenohypophysis (anterior pituitary) and the neurohypophysis (posterior pituitary).The anterior pituitary has three main regions:Pars distalis: Where the main hormone production occursPars tuberalis: Joins the pituitary stalk arising from the posterior pituitary glandPars intermedia: Divides the anterior and posterior parts of the pituitary gland. The pars distalis forms the majority of the adenohypophysis and resembles a typical endocrine gland.

Ebstein’s anomaly is characterised by apical displacement and adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium, thereby displacing the functional tricuspid orifice apically and dividing the right ventricle into two portions. The main haemodynamic abnormality leading to symptoms is tricuspid valve incompetence. The clinical spectrum is broad| patients may be asymptomatic or experience right-sided heart failure, cyanosis, arrhythmias and sudden cardiac death (SCD). Many Ebstein’s anomaly patients have an interatrial communication (secundum atrial septal defect (ASD II) or patent foramen ovale). Other structural anomalies may also be present, including a bicuspid aortic valve (BAV), ventricular septal defect (VSD), and pulmonary stenosis. The morphology of the tricuspid valve in Ebstein anomaly, and consequently the clinical presentation, is highly variable. The tricuspid valve leaflets demonstrate variable degrees of failed delamination (separation of the valve tissue from the myocardium) with fibrous attachments to the right ventricular endocardium.The displacement of annular attachments of septal and posterior (inferior) leaflets into the right ventricle toward the apex and right ventricular outflow tract is the hallmark finding of Ebstein anomaly.

Somatropin is a recombinant human growth hormone used to treat growth failure conditions associated with natural growth hormone deficiencies. According to the UK National Institute for Health and Care Excellence, these conditions include, Prader-Willi syndrome, Noonan syndrome, short stature Homeobox (SHOX) gene deficiency, Turner’s syndrome, chronic renal insufficiency and children who are small for gestational age. Treatment of short stature in achondroplasia has not seen any significant changes with somatotropin.

Because of the patient’s history of chronic analgesic use of daily paracetamol intake, the most likely diagnosis of this case is Analgesic misuse headache. In these cases, the headache is only temporarily relieved by analgesics. Treatment involves gradual withdrawal of analgesics.

Cleansing and debridement is paramount in dealing with tetanus-prone wounds (severe crushing injuries, piercing wounds, blisters and burns are outstanding examples, particularly if contaminated with dirt, grass or other debris).Prophylaxis then is relatively easy in persons who have been actively immunized by toxoid injections. For them, a “booster” injection is indicated. There is experimental evidence that antibiotics of the tetracycline group, given soon after injury, may have prophylactic effect against tetanus.

Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.

Answer: LaparoscopyThe diagnostic accuracy of laparoscopy for impalpable testis is well recognized. Approximately 20% of undescended testes are truly impalpable, and laparoscopy is actually regarded as the gold standard for their localization| none of the currently available imaging techniques (ultrasound, computerized tomography, or magnetic resonance imaging) has proven to be 100% reliable in predicting the presence or absence of a testis.In this respect, not only can laparoscopy be considered the most reliable tool to provide information on the location of the testis but also to confirm its absence.Undescended testes in boys is a very common congenital abnormality in which one or both testes does not reach the bottom of the scrotum prior to birth. The incidence of the condition is 3–5% among all boys at birth, and decreases to 0.8–1% after 6 months of age.Males with undescended testes have a lower sperm count, poorer quality sperm, and lower fertility rate, compared to males whose testicles descend normally| the rate of subfertility increases with bilateral involvement and increasing age at the time of orchidopexy.

Advanced paternal age is associated with poor quality sperm leading to a reduction in overall fertility along with an increase in the occurrence of various medical disorders in the fetus. Advanced paternal age has been implicated as a risk factor for diseases like retinoblastoma, Marfan’s syndrome, neurofibromatosis, achondroplasia, autism spectrum disorders, schizophrenia, and acute lymphoblastic leukaemia. Down’s syndrome is mostly considered a consequence of advanced maternal age, but advanced paternal age has also been implicated as a risk factor. Turner syndrome is not found to be caused by advanced paternal age.

Fragile X syndrome is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females.Affected individuals usually have delayed development of speech and language by age 2. Most males with fragile X syndrome have mild to moderate intellectual disability, while about one-third of affected females are intellectually disabled. Children with fragile X syndrome may also have anxiety and hyperactive behaviour such as fidgeting or impulsive actions. They may have attention deficit disorder (ADD), which includes an impaired ability to maintain attention and difficulty focusing on specific tasks. About one-third of individuals with fragile X syndrome have features of autism spectrum disorder that affect communication and social interaction. Seizures occur in about 15 percent of males and about 5 percent of females with fragile X syndrome.Most males and about half of females with fragile X syndrome have characteristic physical features that become more apparent with age. These features include a long and narrow face, large ears, a prominent jaw and forehead, unusually flexible fingers, flat feet, and in males, enlarged testicles (macroorchidism) after puberty.

Blood culture and sensitivity will distinguish the bacteria that is responsible for the infection and the effective antibiotic treatment to which the bacteria is sensitive.

Tanner stage two presents with the following: Downy hair, Breast bud palpable under areola (1st pubertal sign in females).Stage 1 (prepubertal) – elevation of papilla only – no pubic hairStage 2 – breast bud forms – sparse, slightly pigmented hair on labia majoraStage 3 – Breast begins to become elevated, extends beyond areola borders – hair becomes more coarse and curlyStage 4 – increased size and elevation. Areola and papilla form secondary mound – adult like, but sparing medial thighsStage 5 – final size, areola returns but papilla remains projected – hair extends to medial thighs

Spontaneous intestinal perforation (SIP) of the new-born, also referred to as isolated perforation or focal intestinal perforation (FIP) of the new-born, is a single intestinal perforation that is typically found at the terminal ileum. SIP occurs primarily in preterm infants with very low birth weight (VLBW, birth weight <1500 g) and extremely low birth weight (ELBW, birth weight <1000 g), umbilical catheter placement, maternal drug use and twin-to-twin transfusion syndrome. SIP is a separate clinical entity from necrotizing enterocolitis, the most severe gastrointestinal complication of preterm infants.

Androgen insensitivity syndrome (AIS), previously referred to as testicular feminization, is an X-linked disorder in which the patients are genotypically male (possessing and X and Y chromosome) and phenotypically female. This disorder is rare, with reported incidences from 1 in 20,000 to 1 in 60,000 live male births, and is the result of a missing gene on the X chromosome that is responsible for the cytoplasmic or nuclear testosterone receptor. In its absence, the gonad, which is a testis, produces normal amounts of testosterone| however, the end tissues are unable to respond due to the deficient receptors leading to the external genitalia developing in a female fashion. Anti-Mullerian hormone, which is produced by the testis, is normal in these patients, leading to regression of the Mullerian duct. Wolffian duct development, which depends on testosterone, does not occur as the ducts lack the receptors. The cumulative effect is a genotypic male with normal external female genitalia (without pubic or axillary hair), no menses, normal breast development, short or absent vagina, no internal sex organs, and the presence of testis. Frequently, these patients have bilateral inguinal hernias in childhood, and their presence should arouse suspicion of the diagnosis.

Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive defects in enzymes that are responsible for cortisol, aldosterone, and, in very rare cases, androgen synthesis. All forms of CAH are characterized by low levels of cortisol, high levels of ACTH, and adrenal hyperplasia. The exact clinical manifestations depend on the enzyme defect. The most common form of CAH, which is caused by a deficiency of 21β-hydroxylase, presents with hypotension, ambiguous genitalia, and virilization (in the female genotype), and/or precocious puberty (in both males and females). It is further characterized by hyponatremia, hyperkalaemia, and metabolic acidosis. Increased levels of 17-hydroxyprogesterone confirm the diagnosis of 21β-hydroxylase deficiency. Treatment of CAH involves lifelong glucocorticoid replacement therapy. Patients with a 21β-hydroxylase deficiency also require mineralocorticoid replacement with fludrocortisone. Complications of CAH include severe hypoglycaemia, adrenal insufficiency, and/or a failure to thrive.

Arterial blood gas is useful for the evaluation of oxygen and carbon dioxide gas exchange, respiratory function including hypoxia, and acid/base balance. This will quickly indicate if assisted ventilation is required for this patient.