Errata Grand Test 89

Q-55 Concerning CNS involvement in AIDS:
a. Toxoplasma may give rise to a focal lesion with neurological weakness.
b. The HIV virus can be isolated from the brain of an encephalopathic patient.
c. A diagnostic elevation in the CSF IgM occurs in toxoplasmic infection.
d. Occular involvement may cause blindness.
Ans 55: A,B,D
Reference: Read the text below
Sol:
• Cerebral toxoplasmosis presents very variably, from an acute encephalopathy to subtle neurological syndromes. It should be considered in all undiagnosed neurological disease in the under ones, especially if there are retinal lesions.
• Characteristic are hydrocephalus, seizures with focal defects, spinal or bulbar palsies, microcephaly, and decreased IQ. Investigations such as skull x-ray or CT scan show calcification of the periventricular area, tachyzoites in the CSF and positive blood titres.
• Pyrimethamine and Sulphadiazine have a synergistic effect in treating it, and folinic acid may be necessary to prevent seizures.


Q-135 An 8-year-old boy with sickle cell disease presents with left leg pain and a high fever. He has been refusing to walk since yesterday. On physical examination, his temperature is 39.8 C (103.6 F), blood pressure is 122/68 mm Hg, pulse is 102/min, and respirations are 20/min. His left femur is tender to palpation 3 cm above the left knee, and there is marked soft tissue swelling. A plain film of his left leg is normal. A bone scan shows increased uptake around the metaphysis of the left femur. Which of the following is the most likely pathogen?
a. Escherichia coli
b. Haemophilus influenzae
c. Salmonella
d. Staphylococcus aureus
Ans 135: (c) Salmonella
Ref– Read the text below
Sol:
• Osteomyelitis is a pyogenic infection of the bone. The pathogenesis of the disease is similar to septic arthritis, with the origin of infection occurring from hematogenous spread, direct extension of a local infection, or direct inoculation of bone either from trauma (e.g.puncture wound or open fracture) or surgical manipulation. In children, the most frequent presentation is acute hematogenous spread.
• The most common location of osteomyelitis is the metaphysis of the distal femur and proximal tibia.
• The most prevalent pathogens are the same as those seen in septic arthritis. Staphylococcus aureus is the most common pathogen, with group A beta-hemolytic streptococci a distant second.
• Neonates are at risk for group B beta-hemolytic streptococci. Haemophilus influenzae may occur in infants and young children, but it is not seen as frequently as in septic arthritis.
• In addition, children with H. influenzae osteomyelitis usually have fever and concomitant joint infection. Patients with puncture wounds of the foot are susceptible to Pseudomonas aeruginosa osteomyelitis.
• Patients with sickle cell disease are at risk for infection by Salmonella and other gram-negative bacteria, and patients in the 18- to 48-month age range are at increased risk for acute recurrent Salmonella osteomyelitis.
• Salmonella osteomyelitis frequently involves multiple sites and creates punched-out destructive lesions of the metaphysis and diaphysis. However, even in patients with sickle cell disease, Staphylococcus aureus is still the most common pathogen for osteomyelitis.
• Most patients with osteomyelitis will present with a chief complaint of fever and bone pain. The pain is usually severe, constant, and aggravated by motion. The older the child, the more exquisite the point tenderness, because the bone has a thicker metaphyseal cortex with a dense fibrous periosteum. Localized swelling, warmth, and erythema are signs seen late in the infection, as the periosteum becomes more involved.
• Neonates can present with vague symptoms, consisting only of irritability and poor feeding, or can show signs of fulminant sepsis. The peripheral white blood cell count may be normal, or elevated with a left shift. The erythrocyte sedimentation rate (ESR) is usually elevated, and blood cultures are positive in approximately 60% cases.
• Bone cultures taken either surgically or by needle aspiration result in a culture yield of 80%. Plain radiographs may be normal for up to 2 weeks from the onset of illness, and the earliest signs on plain films are soft tissue swelling and displacement of muscle plane.
• Bony changes begin to appear by 7-10 days, starting with a hazy appearance of the metaphysis followed by irregular areas of trabecular necrosis and absorption. Eventually, subperiosteal new bone formation occurs as the infection spreads through the cortex. A bone scan usually diagnoses osteomyelitis as early as 24-48 hours from onset.
• Treatment should begin with empiric parenteral antibiotics. The selection of antibiotic should include coverage of Staphylococcus aureus, as well as other organisms; the agent can probably be based on the patient's age and history of illness. Surgical debridement may be necessary if pus is present on needle aspiration, or if evidence of either joint involvement or abscess is present.

Q-178 A 32-year-old farmer presents to the emergency room with a crushing injury of the index finger and thumb that occurred while he was working with machinery in his barn. Records show that he received three doses of Td in the past,and that his last dose was given when he was 25 years old. In addition to proper wound cleaning and
management, which of the following is the most appropriate prevention intervention?
a. Administration of tetanus toxoid
b. Administration of tetanus immunoglobulin only
c. Administration of tetanus toxoid and immunoglobulin
d. Administration of tetanus and diphtheria toxoid
Ans 178 : (d) Administration of tetanus and diphtheria toxoid
Ref– Read the text below
Sol:

Q-220 Abortion is defined as expulsion of fetus
a. Before Viability
b. Before 28 weeks
c. Any of the above
d. None of the above
Ans 220: (a) Before Viability

• Abortion is the termination of pregnancy before the period of viability which is considered to occur at 28th Week
• However for international acceptance, the limit of viability is brought down to either 20th week or fetus weighing 500 gm.
• If the expelled fetus weighs less than 500 gm, it is called abortus. The term miscarriage, which is mostly used, is synonymous with abortion

Q-226 Which one of the following is a cofactor and not a coenzyme?
a. Biotin
b. Tetrahydrofolic acid
c. Copper
d. Methylcobalamin
Ans 226 : (c) Copper
Ref– Read the text below
Sol:
• Cofactors are distinguished from coenzymes because cofactors do not function in group transfer and do not undergo chemical reactions (other than changes in valence due to oxidation/ reduction).
• Cofactors are usually metallic ions rather than organic molecules. Examples of cofactors include copper in cytochrome oxidase, iron in all the cytochromes, magnesium for all enzymes utilizing ATP, and zinc in lactate dehydrogenase.
• Methylcobalamin, biotin, tetrahydrofolic acid, and pyridoxal phosphates all assist with enzyme catalysis by transfer of groups from or to the primary substrate.

Q-282 Read the statements carefully and find out which is false :
a. No exact criteria exist for defining when acute osteomyelitis becomes chronic.
b. The hallmark of chronic osteomyelitiis is the presence of dead bone (the sequestrum)
c. Involucrum (reactive bony encasement of the sequestrum), local bone loss, persistent drainage, and/or sinus tracts are other common features of actute disease.
d. The patient with chronic osteomyelitis commonly presents with chronic pain and sinus formation with purulent drainage.
Ans 282: (c) Involucrum (reactive bony encasement of the sequestrum), local bone loss, persistent drainage, and/or sinus tracts are other common features of actute disease.
Reference: Read the text below
Sol:
• Involucrum (reactive bony encasement of the sequestrum) local bone loss, persistent drainage, and/or sinus tracts are other common features of chronic disease, prospects of halting the infection are reduced when the integrity of surrounding soft tissue is poor or the bone are unstable due to an infected nounion or an adjacent septic joint.
• Squamous cell carcinoma at the site of tissue draingage and amyloidosis are rare complications of chronic osteomyelities.

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