Answer: Acute Epstein Barr virus infection

The 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, and
sweats,
sore throat,
swollen lymph nodes in the neck, and
sometimes 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.

Creatine kinase-MB is a test that usually is ordered when the patient has chest pain as a cardiac marker. When a heart attack is suspected and a troponin test (which is more specific for heart damage), is not available CK-MB is ordered. There are 3 forms of CK: CK-MM, CK-BB and CK-MB. CK-MB is commonly found in heart tissue, therefore injured heart muscle cells release CK-MB into the blood. Elevated CK-MB levels indicate that it is probable that a person has recently had a heart attack.

The rough endoplasmic reticulum is the factory for the manufacturing of proteins. It contains ribosomes attached to it and transports proteins that are destined for membranes and secretions. The rough ER is connected to the nuclear envelope and to the cisternae of the Golgi apparatus by vesicles that shuttle between the two compartments.

The basilic vein is one of two veins found in the forearm, the other is the cephalic vein. These veins originate from the deep venous arch of the hand. The cephalic vein ascends along the lateral side of the forearm, and the basilic vein runs up the medial side of the forearm.

The second pharyngeal arch or hyoid arch, is the second of six pharyngeal arches that develops in fetal life during the fourth week of development and assists in forming the side and front of the neck. Derivatives:
Skeletal – From the cartilage of the second arch arises:
Stapes,
Temporal styloid process,
Stylohyoid ligament, and
Lesser cornu of the hyoid bone.
Muscles:
Muscles of face
Occipitofrontalis muscle
Platysma
Stylohyoid muscle
Posterior belly of Digastric
Stapedius muscle
Auricular muscles
Nerve supply: Facial nerve

Shock is a life-threatening condition that occurs when the organs and tissues of the body are not receiving a sufficient flow of blood. Lack of blood flow, oxygen and nutrients results in the inability to function properly and damage to many organs. Shock requires immediate treatment because, if left untreated the impaired tissue perfusion and cellular hypoxia can cause irreversible tissue injury, collapse, coma or even death. There are various types of physiological shock, including: cardiogenic (due to heart damage), hypovolaemic (due to low total volume of blood or plasma), neurogenic (due to nervous system damage), septic (due to infections) and anaphylactic shock (due to allergic reactions). Hypovolaemic shock can be caused by blood loss due to trauma, internal bleeding or other fluid loss due to severe burns, prolonged diarrhoea, vomiting and sweating.

A benign tumour arising from the ovarian stroma, fibrothecoma are bilateral in 10% cases. The thecoma component of the tumour can produce oestrogen leading to endometrial hyperplasia. The thecoma is rich in lipid content and is responsible for the yellowish appearance of the tumour. Meig’s syndrome is the presence of fibrothecoma with a right-sided hydrothorax.

The possible causes of post-operative pneumothorax after thoracotomy and esophagectomy include lung parenchymal leak/injury, bronchopleural fistula, ruptured bullae and malpositioned chest drains. When suction is applied to the chest drainage system, active and persistent bubbling may be seen. Although an anastomotic leak may produce a small pneumothorax, a large volume air leak is more indicative of lung injury.

Because of the substantial risk of thromboembolism early after valve replacement, perioperative initiation of anticoagulation is necessary, despite the increased risk for bleeding. Anticoagulation should be initiated within 24 h after the procedure with unfractionated heparin or low-molecular-weight heparin (LMWH).
Heparin is monitored by checking the activated partial thromboplastin time or anti-Xa activity.
Oral anticoagulants are monitored by INR.

Anterior cruciate ligament (ACL) injuries are most often a result of low-velocity, noncontact, deceleration injuries and contact injuries with a rotational component. Contact sports also may produce injury to the ACL secondary to twisting, valgus stress, or hyperextension all directly related to contact or collision.

Symptoms of an acute ACL injury may include the following:
– Feeling or hearing a “pop” sound in the knee
– Pain and inability to continue the activity
– Swelling and instability of the knee
– Development of a large hemarthrosis

Differential Diagnoses
A- Medial Collateral Knee Ligament Injury
Contact, noncontact, and overuse mechanisms are involved in causing MCL injuries.
Contact injuries involve a direct valgus load to the knee. This is the usual mechanism in a complete tear.
Noncontact, or indirect, injuries are observed with deceleration, cutting, and pivoting motions. These mechanisms tend to cause partial tears.
Overuse injuries of the MCL have been described in swimmers. The whip-kick technique of the breaststroke has been implicated. This technique involves repetitive valgus loads across the knee.

B- Posterior Cruciate Ligament Injury
Knowledge of the mechanism of injury is helpful. The following 4 mechanisms of PCL injury are recognized:
– A posteriorly directed force on a flexed knee, e.g., the anterior aspect of the flexed knee striking a dashboard, may cause PCL injury.
– A fall onto a flexed knee with the foot in plantar flexion and the tibial tubercle striking the ground first, directing a posterior force to the proximal tibia, may result in injury to the PCL.
– Hyperextension alone may lead to an avulsion injury of the PCL from the origin. This kind of injury may be amenable to repair.
– An anterior force to the anterior tibia in a hyperextended knee with the foot planted results in combined injury to the knee ligaments along with knee dislocation.

In chronic PCL tears, discomfort may be experienced with the following positions or activities:
– A semi flexed position, as with ascending or descending stairs or an incline
– Starting a run
– Lifting a load
– Walking longer distances
– Retro patellar pain symptoms may be reported as a result of posterior tibial sagging.
– Swelling and stiffness may be reported in cases of chondral damage.
– Individuals may describe a sensation of instability when walking on uneven ground
– Medial joint line pain may be reported.

Allograft coronary artery disease (CAD) can begin right after the transplant and is the major cause of later death in cardiac transplant recipients. This form of atherosclerosis progresses quickly resulting in allograft failure. Due to lack of premonitory symptoms CAD may lead to sudden death.

The most common cause of hypovolaemic hyponatraemia include: liver cirrhosis, congestive heart failure and nephrotic syndrome. In hypovolaemic hyponatraemia, both sodium and water content increase: Increase in sodium content leads to hypervolemia and water content to hyponatraemia.

Nocardia is a Gram-positive aerobic actinomycete. Several species have been identified but the most common human pathogen is Nocardia asteroides. The predominant clinical finding in the majority of patients affected by nocardiosis is pulmonary disease. Predisposing factors for pulmonary nocardiosis include leukaemia, human immunodeficiency virus (HIV) infection, organ transplantation, diabetes and receiving prolonged corticosteroids.

The complications of central vein catheterization (CVC) include infection, thrombosis, occlusion, and, in particular, mechanical complications which usually occur during insertion and are closely related to the anatomic location of the central veins. Infectious complications are reported to occur in 5% to 26% of patients, mechanical complications in 5% to 19%, and thrombotic complications in 2% to 26%. Mechanical complications associated with the insertion of central lines include arterial puncture, hematoma, haemothorax, pneumothorax, arterial-venous fistula, venous air embolism, nerve injury, thoracic duct injury (left side only), intraluminal dissection, and puncture of the aorta
Pneumothorax is one of the most common CVC insertion complications, reportedly representing up to 30% of all mechanical adverse events of CVC insertion.
Clinician-performed bedside US allows the diagnosis of pneumothorax to be made immediately, with a high degree of sensitivity and with better accuracy than supine chest films and equal to that of CT scan.
Tension pneumothorax is classically characterized by hypotension and hypoxia. On examination, breath sounds are absent on the affected haemothorax and the trachea deviates away from the affected side. The thorax may also be hyper resonant; jugular venous distention and tachycardia may be present.
If a pneumothorax is diagnosed the treatment strategy should be determined by the following factors: (I) size; (II) symptoms; (III) spontaneous breathing or use of mechanical ventilation; (IV) clinical diagnosis of a tension pneumothorax.

Treatment consisted of: (I) observation; (II) outpatient insertion of a Heimlich valve; (III) inpatient tube thoracostomy.

The vagus nerve (cranial nerve X) innervates both the palatoglossus and levator veli palatini muscles.

CIN (Cervical intraepithelial neoplasia) is considered a precursor of cervical cancer and is caused due to infection with human papillomavirus (HPV) types 16, 18, 31, 33, 35 or 39. The risk factors for cervical cancer include multiple sex partners, young age at the time of first intercourse, intercourse with men whose previous partners had cervical cancer. Also, smoking and immunodeficient states are considered contributory. CIN is graded as mild (grade I), moderate (grade II) and severe dysplasia or carcinoma in situ (grade III). CIN III rarely regresses spontaneously and can lead to invasive carcinoma by invading the basement membrane. Squamous cell carcinomas are the commonest cervical cancer seen in 80-85% of all cases. Others are commonly adenocarcinomas. Cervical cancer can spread by direct extension, lymphatic spread to pelvic and para-aortic nodes or by hematogenous route.

Metaplasia is the transformation of one type of epithelium into another as a means to better cope with external stress on that epithelium. In this case metaplasia occurs due to the inflammation resulting from gastro-oesophageal reflux disease. Dysplasia is disordered cellular growth. Hyperplasia is an increase in cell number but not cell type i.e. transformation. Carcinoma is characterized by cellular atypia. Ischaemia would result in necrosis with ulceration. Carcinoma insitu involves dysplastic atypical cells with the basement membrane intact and atrophy would mean a decrease in number of cells.

Buspirone is an anxiolytic agent and a serotonin-receptor agonist that belongs to the azaspirodecanedione class of compounds. It shows no potential for addiction compared with other drugs commonly prescribed for anxiety, especially the benzodiazepines. The development of tolerance has not been noted. It is primarily used to treat generalized anxiety disorders. It is also commonly used to augment antidepressants in the treatment of major depressive disorder.

Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.

Tubulointerstitial nephritis is the term given to primary injury to renal tubules and the renal interstitium, which ultimately results in a decline in renal function. Acute tubulointerstitial nephritis (acute pyelonephritis) is often seen as a result of infection or drug reactions. The most characteristic feature of this condition on urine analysis is the presence of white blood cell casts.

In this case, there is no delay in treatment and the mechanism by which the fracture occurred fits accidental fracture.

A statement from the parent or guardian and any witnesses regarding how the child sustained the injury will help determine whether the injury is accidental or abusive. A statement from the parent or guardian explaining why he or she delayed in seeking medical treatment is important to the investigation because caretakers often postpone medical treatment or fail to provide treatment for an injured child to hide physical abuse. The abusing parent or caregiver may also put a child in oversized clothing or keep the child inside a residence for extended periods of time in an attempt to conceal the child’s injuries.

Parents who inflict fractures on their children tend to minimize the severity of the accident purported to cause the fracture, whereas many parents of children with accidental fractures will relate a history of high-energy events.

Gout is a rheumatic disease caused by the precipitation of monosodium urate crystals into tissues, usually joints. This causes acute or chronic pain; the acute illness initially affects only one joint, often the first metatarsophalangeal joint. The diagnosis of the disease requires the identification of crystal in the synovial fluid. These crystals are needle-shaped and strongly negatively birefringent.

Answer: Yersinia enterocolitica

Yersinia enterocolitica (see the image below) is a bacterial species in the family Enterobacteriaceae that most often causes enterocolitis, acute diarrhoea, terminal ileitis, mesenteric lymphadenitis, and pseudo appendicitis but, if it spreads systemically, can also result in fatal sepsis. Symptoms of Y enterocolitica infection typically include the following:

Diarrhoea – The most common clinical manifestation of this infection; diarrhoea may be bloody in severe cases

Low-grade fever

Abdominal pain – May localize to the right lower quadrant

Vomiting – Present in approximately 15-40% of cases

Mesenteric adenitis, mesenteric ileitis, and acute pseudo appendicitis
These manifestations are characterized by the following symptoms (although nausea, vomiting, diarrhoea, and aphthous ulcers of the mouth can also occur):

Fever

Abdominal pain

Tenderness of the right lower quadrant

Leucocytosis

Pseudo appendicitis syndrome is more common in older children and young adults. Patients with Y enterocolitica infection often undergo appendectomy; several Scandinavian studies suggested a prevalence rate of 3.8-5.6% for infection with Y enterocolitica in patients with suspected appendicitis.

Analysis of several common-source outbreaks in the United States found that 10% of 444 patients with symptomatic, undiagnosed Y enterocolitica infection underwent laparotomy for suspected appendicitis.

Human clinical Y enterocolitica infections ensue after ingestion of the microorganisms in contaminated food or water or by direct inoculation through blood transfusion.

Y enterocolitica is potentially transmitted by contaminated unpasteurized milk and milk products, raw pork, tofu, meats, oysters, and fish. Outbreaks have been associated with raw vegetables; the surface of vegetables can become contaminated with pathogenic microorganisms through contact with soil, irrigation water, fertilizers, equipment, humans, and animals.

Pasteurized milk and dairy products can also cause outbreaks because Yersinia can proliferate at refrigerated temperatures.

Animal reservoirs of Y enterocolitica include swine (principle reservoir), dogs, cats, cows, sheep, goats, rodents, foxes, porcupines, and birds.

Reports of person-to-person spread are conflicting and are generally not observed in large outbreaks. Transmission via blood products has occurred, however, and infection can be transmitted from mother to new-born infant. Faecal-oral transmission among humans has not been proven.

By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.

The most likely vascular structure is the inferior vena cava. The inferior vena cava is formed by the joining of the two common iliac arteries, the right and the left iliac artery, at the level of the fifth lumbar vertebra( L5). The inferior vena cava passes along the right side of the vertebral column. It enters the thoracic cavity into the underside of the heart through the caval opening of the diaphragm at the level of the eight thoracic vertebra (T8).

Anal fissure is a tear in the anoderm distal to the dentate line. It is the most common cause of severe anal pain. It is equally one of the most common reasons for bleeding per anus in infants and young children. The pain of an anal ulcer is intolerable and always disproportionate to the severity of the physical lesion. It may be so severe that patients may avoid defecation for days together until it becomes inevitable. This leads to hardening of the stools, which further tear the anoderm during defecation, setting a vicious cycle. The fissures can be classified into 1] Acute or superficial and 2] Chronic fissure in ano.

Initial therapy for an anal fissure is medical, and more than 80% of acute anal fissures resolve without further therapy.
The goals of treatment are to relieve the constipation and to break the cycle of hard bowel movement, associated pain, and worsening constipation. Softer bowel movements are easier and less painful for the patient to pass.

First-line medical therapy consists of therapy with stool-bulking agents, such as fibre supplementation and stool softeners. Laxatives are used as needed to maintain regular bowel movements. Mineral oil may be added to facilitate passage of stool without as much stretching or abrasion of the anal mucosa, but it is not recommended for indefinite use. Sitz baths after bowel movements and as needed provide significant symptomatic relief because they relieve some of the painful internal sphincter muscle spasm.
Recurrence rates are in the range of 30-70% if the high-fibre diet is abandoned after the fissure is healed. This range can be reduced to 15-20% if patients remain on a high-fibre diet.

Second-line medical therapy consists of intra-anal application of 0.4% nitroglycerin (NTG; also called glycerol trinitrate) ointment directly to the internal sphincter.
Some physicians use NTG ointment as initial therapy in conjunction with fibre and stool softeners, and others prefer to add it to the medical regimen if fibre and stool softeners alone fail to heal the fissure. NTG ointment is thought to relax the internal sphincter and to help relieve some of the pain associated with sphincter spasm; it also is thought to increase blood flow to the anal mucosa.
Unfortunately, many people cannot tolerate the adverse effects of NTG, and as a result, its use is often limited. The main adverse effects are headache and dizziness; therefore, patients should be instructed to use NTG ointment for the first time in the presence of others or directly before bedtime.
Analogous to the use of NTG intra-anal ointment, nifedipine ointment is also available for use in clinical trials. It is thought to have similar efficacy to NTG ointment but with fewer adverse effects.

Botulinum toxin has been used to treat acute and chronic anal fissures. It is injected directly into the internal anal sphincter, in effect performing a chemical sphincterotomy. The effect lasts about 3 months, until nerve endings regenerate. This 3-month period may allow acute fissures (and sometimes chronic fissures) to heal and symptoms to resolve. If botulinum toxin injection provides initial relief of symptoms but there is a recurrence after 3 months, the patient may benefit from surgical sphincterotomy.

Surgical therapy is usually reserved for acute anal fissures that remain symptomatic after 3-4 weeks of medical therapy and for chronic anal fissures.
Sphincter dilatation
Lateral internal sphincterotomy

The lesser curvature of the stomach is supplied by the left gastric artery along with the right gastric artery. These two arteries are the ones to most likely be ligated if bleeding was to be stopped at the lesser curvature of the stomach. The splenic artery branches from the celiac branch and supplies the spleen. The left gastro-omental, the right and left gastroepiploic arteries supply the greater curvature.

The large intestine doesn’t have a continuous layer of longitudinal muscle. Instead, it has three strips of longitudinal muscle called taenia coli. The large intestine is covered with omental appendages that are fat filled. It is also folded into sacculations called haustrations. Serosa is a general term for the outermost coat or serous layer of a visceral structure that lies in the body cavities of the abdomen or thorax.
Complete circular folds are only found in the small intestine.
Valvulae conniventes or valves of Kerckring are the circular folds which are large valvular flaps projecting into the lumen of the small bowel.

The eighth cervical nerve is one of the contributors of the ulnar nerve. The ulnar nerve supplies the hypothenar muscles which include the opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis, and palmaris brevis.

Pfannenstiel incision (a transverse suprapubic incision) is made below the arcuate line. Thus, there is no posterior layer of the rectus sheath here, only the transversalis fascia lines the inner layer of the rectus abdominis. The layers traversed include: skin, superficial fascia (fatty and membranous), deep fascia, anterior rectus sheath, rectus abdominis muscle, transversalis fascia, extraperitoneal connective tissue and peritoneum.