Among the given options, the inability to grip a sheet of paper between his fingers when the hand is placed flat on the table is the feature of ulnar nerve injury. Rationale:The ulnar nerve (usually) supplies sensation to the skin of the fifth and the ulnar side of the fourth finger, front and back. Following the injury of the nerve, the following functions are impaired:- There is a sympathetic interruption, with the absence of sweating in the affected area. – The thenar muscles are supplied by the median nerve and are therefore spared. – The ulnar nerve also supplies the muscles of the hypothenar eminence. – Although the ring and little fingers are held in the clawed position when the nerve is injured at the wrist, a high lesion paralyses the long flexors to these two fingers and results in the loss of this sign. The test for paralysis of the palmar interossei, supplied by the ulnar nerve, is the inability to adduct the fingers and thus to be unable to grip a sheet of paper between them.

In pyloric stenosis a new-born baby presents with a history of vomiting, constipation and deranged electrolytes. Excessive vomiting leads to hypokalaemia. Difficulty in food passing from the stomach to the small intestine causes constipation. Hypokalaemia also causes constipation. None of the other disorders mentioned present with the hypokalaemia, vomiting and constipation triad in a new-born.

The level of statistical significance is often expressed as a p-value between 0 and 1. The smaller the p-value, the stronger the evidence that you should reject the null hypothesis.A p-value less than 0.05 (typically ≤ 0.05) is statistically significant. It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random). Therefore, we reject the null hypothesis, and accept the alternative hypothesis.However, this does not mean that there is a 95% probability that the research hypothesis is true. The p-value is conditional upon the null hypothesis being true is unrelated to the truth or falsity of the research hypothesis.A lower p-value is sometimes interpreted as meaning there is a stronger relationship between two variables. However, statistical significance means that it is unlikely that the null hypothesis is true (less than 5%).To understand the strength of the difference between two groups (control vs. experimental) a researcher needs to calculate the effect size.

The sensitivity of a screening test can be described in a variety of ways, typically such as sensitivity being the ability of a screening test to detect a true positive, being based on the true positive rate, reflecting a test’s ability to correctly identify all people who have a condition, or, if 100%, identifying all people with a condition of interest by those people testing positive on the test.The specificity of a test is defined in a variety of ways, typically such as specificity is the ability of a screening test to detect a true negative, being based on the true negative rate, correctly identifying people who do not have a condition, or, if 100%, identifying all patients who do not have the condition of interest by those people testing negative on the test.Sensitivity=[a/(a+c)]×100Specificity=[d/(b+d)]×100a: True positiveb: False Positivec: False negatived: True negative

Stridor is a sign of upper airway obstruction. One of the most common causes of stridor in children is laryngomalacia. In the absence of laryngomalacia, stridor presenting with respiratory distress, few chest signs and no preceding coryza symptoms or fever all point to the inhalation of a foreign object. This is common in children, with a peak incidence between 1 and 2 years of age. This child did not present with a high temperature, usually indicative of epiglottitis . The incidence of epiglottis has decreased due to the H. Influenza type b vaccine. Additionally viral croup and bronchiolitis present with upper respiratory tract infection. Asthma rarely presents with stridor but is rather associated with a wheeze.

The boy is most probably a type 1 diabetic patient. Such a condition can affect the behaviour and psychological state of a young child reflected in their behaviour. The parents should seek the help of a clinical psychologist.

Pubic lice are commonly referred to as ‘crabs’ because of their short, broad body (about 1 mm), and large front claws. Pubic lice infestation is diagnosed by finding a “crab” louse or eggs on hair in the pubic region or, less commonly, elsewhere on the body (eyebrows, eyelashes, beard, moustache, armpit, perianal area, groin, trunk, scalp). Although pubic lice and nits can be large enough to be seen with the naked eye, a magnifying lens may be necessary to find lice or eggs.Pubic lice are transmitted from person to person most-commonly via sexual contact, although fomites (bedding, clothing) may play a minor role in their transmission.

Haemophilia A and haemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition.

Precocious puberty refers to the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal.Most patients, particularly girls suspected of having central precocious puberty, are otherwise healthy children whose pubertal maturation begins at the early end of the normal distribution curveIn a series of more than 200 patients evaluated at a single medical centre, central precocious puberty occurred 5 times more often in girls than boys.GnRH-dependent precocious puberty is treated with GnRH agonists or Luteinizing Hormone Releasing Hormone (LHRH). Follow up every 4-6 months to ensure that progression of puberty has been arrestedFavourable signs include normalization of accelerated growth, reduction (or at least no increase) in size of breasts, and suppression of gonadotropin levels after a challenge of GnRHThe ideal testing frequency has not been established. Monitor bone age yearly to confirm that the rapid advancement seen in the untreated state has slowed, typically to a half year of bone age per year or less

Congenital duodenal atresia is one of the more common intestinal anomalies treated by paediatric surgeons, occurring 1 in 2500-5000 live births. In 25-40% of cases, the anomaly is encountered in an infant with trisomy 21 (Down syndrome).Presenting symptoms and signs are the results of high intestinal obstruction. Duodenal atresia is typically characterized by the onset of vomiting within hours of birth. While vomitus is most often bilious, it may be nonbilious because 15% of defects occur proximal to the ampulla of Vater. Occasionally, infants with duodenal stenosis escape detection of an abnormality and proceed into childhood or, rarely, into adulthood before a partial obstruction is noted. Nevertheless, one should assume any child with bilious vomiting has a proximal GI obstruction until proven otherwise, and further workup should be begun expeditiously.Once delivered, an infant with duodenal atresia typically has a scaphoid abdomen. One may occasionally note epigastric fullness from dilation of the stomach and proximal duodenum. Passing meconium within the first 24 hours of life is not usually altered. Dehydration, weight loss, and electrolyte imbalance soon follow unless fluid and electrolyte losses are adequately replaced. If intravenous (IV) hydration is not begun, a hypokalaemic/hypochloraemic metabolic alkalosis with paradoxical aciduria develops, as with other high GI obstruction. An orogastric (OG) tube in an infant with suspected duodenal obstruction typically yields a significant amount of bile-stained fluid.

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.

Prepubertal atrophic vaginitis is due to a lack of vaginal oestrogen. The pathophysiology behind prepubertal atrophic vaginitis:1.The proximity of the vagina to the anus2.Lack of oestrogen – leads to thinning of the vaginal mucosa3.Lack of pubic hair to protect the area4.Lack of labial fat pads

Epiglottitis is characterized by the abrupt onset of severe symptoms. Without airway control and medical management, symptoms may rapidly progress to respiratory obstruction and death in a matter of hours.Usually, no prodromal symptoms occur in children. Fever is usually the first symptom, and temperatures often reach 40°C. Acute epiglottitis may result in sudden, complete upper airway obstruction. Classic signs in children are four D’s: drooling, dyspnoea, dysphagia, and dysphonia.

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.

47,XYY syndrome is characterized by an extra copy of the Y chromosome in each of a male’s cells. Although many males with this condition are taller than average, the chromosomal change sometimes causes no unusual physical features. Most males with 47,XYY syndrome have normal production of the male sex hormone testosterone and normal sexual development, and they are usually able to father children.47,XYY syndrome is associated with an increased risk of learning disabilities and delayed development of speech and language skills. Affected boys can have delayed development of motor skills or hypotonia.Other signs and symptoms of this condition include hand tremors or other involuntary movements (motor tics), seizures, and asthma. Males with 47,XYY syndrome have an increased risk of behavioural, social, and emotional difficulties compared with their unaffected peers. These problems include attention-deficit/hyperactivity disorder (ADHD)| depression| anxiety| and autism spectrum disorder.Physical features related to 47,XYY syndrome can include increased belly fat, macrocephaly, macrodontia, flat feet (pes planus), fifth fingers that curve inward (clinodactyly), widely spaced eyes (ocular hypertelorism), and scoliosis. These characteristics vary widely among affected boys and men.

Maternal and fetal toxoplasma infection may be avoided by advising pregnant women to wear gloves when gardening or handling cat litter and to cook meat thoroughly. Affected babies are treated with pyrimethamine, sulfadiazine, and folic acid.

Endoderm derivatives include the epithelium of the following: gastrointestinal tract and its glands, glandular cells of the liver and pancreases, urachus and urinary bladder, pharynx, trachea and alveoli, part of the tonsils, thyroid and parathyroid, tympanic cavity and thymus and part of the anterior pituitary gland.

Among the options provided, a 1-year-old child will be able to understand object permanence e.g. understands that objects continue to exist even when they can’t be seen, e.g. looking for a fallen toy.At the age of 1 year, children should have developed an accurate pincer grip and be able to see and co-ordinate and manipulate fairly small objects such as a raisin.Gross motor development varies, but the average 1-year-old should be able to stand and cruise around furniture or walk with their hands held but not necessarily walk unaided.Drinking from a cup will become established at around 15 months and scribbling at 18 months.

Reed-Sternberg cells are classically associated with Hodgkin lymphoma.Classical diagnostic Reed-Sternberg cells are large (15 to 45 micrometres), have abundant slightly basophilic or amphophilic cytoplasm and have at least two nuclear lobes or nuclei. Diagnostic Reed-Sternberg cells must have at least two nucleoli in two separate nuclear lobes. The nuclei are large and often rounded in contour with a prominent, often irregular nuclear membrane, pale chromatin and usually one prominent eosinophilic nucleolus, with perinuclear clearing (halo), resembling a viral inclusion.

Allergy: A history of a prior allergic-like reaction to contrast media is associated with an up to a 5-fold increase in the likelihood of experiencing a subsequent reaction. Also, any patient with a predilection to allergic reactions may predispose them to a reaction after the administration of contrast media. Given the increased risk of severe life-threatening anaphylaxis related to the administration of contrast media in the setting of the history of atopy, the risk versus benefits should be discussed before following through with the procedure. A premedication regimen may be used to reduce the risk of anaphylaxis.Asthma: A history of asthma may be indicative of a higher likelihood of developing a contrast reaction. Cardiac status: Attention must be turned to patients with significant cardiac disease (congestive heart failure, aortic stenosis, severe cardiomyopathy, and/or pulmonary hypertension), as higher volumes and osmolality of contrast material may result in an increased risk for a contrast reaction.Renal insufficiency: Contrast nephrotoxicity is defined as the rapid deterioration of renal function after the administration of contrast media when no other aetiology can be determined from the clinical records. The major predisposing risk factors include pre-existing renal insufficiency (defined as serum creatinine level >1.5 mg/dL) and diabetes. Other risk factors include dehydration, cardiovascular disease, the use of diuretics, advanced age (>70 years old), hypertension, and hyperuricemia. Obtaining multiple contrast-enhanced studies within 24 hours is also thought to increase the risk for contrast-induced nephrotoxicity. Miscellaneous: Relative contraindications to the use of high osmolality iodinated contrast media (HOCM) in patients with pheochromocytoma, sickle cell disease, and multiple myeloma have been reported. Although the administration of low osmolality or iso-osmotic contrast media may be beneficial in patients with pheochromocytoma and sickle cell disease, little evidence suggests that these agents mitigate the risks associated with multiple myeloma.

An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions). Wherea = Number of exposed casesb = Number of exposed non-casesc = Number of unexposed casesd = Number of unexposed non-casesOR=(a/c) / (b/d) = ad/bc

Alpha-fetoprotein (AFP) is a plasma protein produced by the embryonic yolk sac and the fetal liver. AFP levels in serum, amniotic fluid, and urine functions as a screening test for congenital disabilities, chromosomal abnormalities, as well as some other adult occurring tumours and pathologies.Pregnant maternal serum AFP levels are elevated in:- Neural tube defects (e.g., spina bifida, anencephaly)- Omphalocele- Gastroschisis- posterior urethral valves- nephrosis- GI obstruction- teratomas

Hyposplenism is associated with thrombocytosis. Other features of hyposplenism are: – Howell-Jolly bodies and acanthocytosis, occurring secondary to haemolysis.- Pappenheimer bodies: These are granular deposits of iron found within the RBCs.- Lymphocytosis and monocytosis.Causes for hyposplenism include:- Congenital asplenia- Iatrogenic splenectomy: Following trauma or treatment for ITP, thalassemia or spherocytosis).- Autosplenectomy: Secondary to sickle cell anaemia, coeliac disease, dermatitis herpetiformis, essential thrombocythemia or splenic arterial thrombosis).

Nonspecific triggers of inflammation in patients with atopic dermatitis may include physical or chemical irritants. The following simple measures should be followed in daily life to reduce the frequency and severity of irritant-induced atopic dermatitis flares :Skin care products that contain alcohol and astringents should be avoided.New clothes should be laundered before use to remove formaldehyde and other chemicals.Liquid detergents are preferred over powder detergents for laundering clothes, as liquids are easier to rinse out. A second rinse cycle may also improve removal of residual detergent.Patients should shower immediately after swimming in chlorinated pools and should subsequently apply moisturizer.Fragrance-free skin products that are hypoallergenic or made for sensitive skin may be less irritating than other kinds of skin products.Prenatal and postnatal probiotic supplementation may be helpful in preventing the development of atopic dermatitis in young children. In a 2008 meta-analysis, the most commonly studied probiotic was Lactobacillus rhamnoses GG. Larger, randomized controlled studies are needed to confirm these initial findings.Breastfeeding during the first 4 months of life may reduce the incidence and severity of childhood atopic disease but only modestly and only in those at high risk.

Infective endocarditis (IE) is an acute infective pathology of the endocardium secondary to some underlying cardiac pathology like VSD and TOF. Most commonly, it is bacterial in origin, caused by staphylococcus aureus in the majority of cases. Clinical features include fever, arthralgias, weight loss, anorexia, new-onset, or changing existing murmur. Skin manifestations include Osler’s nodes, Janeway lesions, splinter haemorrhages, and clubbing. Roth spots are conjunctival haemorrhages found in IE. Beau’s lines are not found in IE.

Power calculations are a important step in study design and preparation, but do not directly help with the interpretation of the results. They are used to determine how many subjects are needed in order to avoid errors in accepting or rejecting the null hypothesis. These calculations are not usually complex and for the best results, the power of the test should be set to above 80%.

The blood-brain barrier (BBB) is a term used to describe the unique properties of the microvasculature of the central nervous system (CNS). CNS vessels are continuous nonfenestrated vessels, but also contain a series of additional properties that allow them to tightly regulate the movement of molecules, ions, and cells between the blood and the CNS.Blood vessels are made up of two main cell types: Endothelial Cells (ECs) that form the walls of the blood vessels, and mural cells that sit on the abluminal surface of the EC layer. The properties of the BBB are largely manifested within the ECs, but are induced and maintained by critical interactions with mural cells, immune cells, glial cells, and neural cells, which interact in the neurovascular unit.Astrocytes are a major glial cell type, which extends polarized cellular processes that ensheath either neuronal processes or blood vessels.This includes regulating the contraction/dilation of vascular smooth muscle cells surrounding arterioles as well as PCs surrounding capillaries. Astrocytes have been identified as important mediators of BBB formation and function because of the ability of purified astrocytes to induce barrier properties.

An incarcerated indirect inguinal hernia presents with abdominal pain, bloating, nausea, vomiting, and intestinal obstruction. It is characterized by the appearance of a tender mass in the inguinal area. Manual reduction in children requires analgesia and sedation.

Ichthyosis vulgaris presents clinically with xerosis, hyperkeratosis, excess scaling, keratosis pilaris, and palmar and plantar hyperlinearity. It most commonly affects the extensor surfaces of the limbs and spares flexor surfaces, the face, and the neck.

Androgen excess is one of the most common causes of advanced bone age. It usually occurs in precocious puberty or congenital adrenal hyperplasia.