BIOCHEMISTRY, BIOMEDICINE & PHARMACEUTICS

Immunoglobulins, also known as antibodies, are proteins produced by the immune system to recognize and neutralize foreign substances such as bacteria, viruses, and toxins. The structure and genetic diversity of immunoglobulins play a critical role in their ability to protect the body against a wide range of pathogens.  The structure of an immunoglobulin molecule consists of two identical heavy chains and two identical light chains, which are linked together by disulfide bonds. Each chain contains a variable region and a constant region. The variable region is responsible for binding to a specific antigen, while the constant region determines the effector function of the antibody, such as activating complement or recruiting immune cells. The genetic diversity of immunoglobulins is generated through a process called somatic recombination. This process involves the rearrangement of gene segments encoding the variable region of the heavy and light chains, resulting in a vast reperto...

          MCQs on Escherichia Coli (E.coli) infections and key characteristics 1. What is the primary habitat of Escherichia coli ? a) Soil b) Human intestines c) Human nose  d) Human skin 2. Which of the following infection is commonly associated with extraintestinal strains of E. coli ? a) Community acquired pneumonia b) Community acquired urinary tract infection (UTI)     c) Hemorrhagic diarrhea d) Traveler's  diarrhea 3. What type of toxin is produced by Enterotoxigenic E. coli (ETEC) strains? a) Alpha toxin  b) Endotoxins c) Heat-Labile Enterotoxin (LT) d) Shiga toxin-producing E. coli (STEC)  4. Which type of E. coli is often referred to as "traveler's diarrhea" due to its association with contaminated water and food in developing countries? a) Enterotoxigenic E. coli (ETEC) b) Enteropathogenic E. coli (EPEC) c) Enterohemorrhagic E. coli (STEC) d) Enteroaggregative E. coli (EAEC) 5. Which of the following transp...

A. Multiple Choice Questions (MCQs) on Infective Endocarditis Question 1: Which of the following is the primary site of infection in infective endocarditis? a) Myocardium b) Pericardium c) Endocardium d) Epicardium Answer: c) Endocardium Explanation: Infective endocarditis involves infection of the endocardium, the inner lining of the heart chambers and valves. Question 2: Which of the following microorganisms is commonly associated with acute, rapidly progressing endocarditis? a) Streptococcus viridans b) Staphylococcus aureus c) Enterococcus faecalis d) Streptococcus bovis Answer: b) Staphylococcus aureus Explanation: Staphylococcus aureus is known for causing acute and aggressive forms of infective endocarditis. Question 3: Which group of microorganisms is often implicated in culture-negative endocarditis cases? a) Streptococcus viridans b) Coagulase-negative Staphylococci c) HACEK group organisms d) Streptococcus pyogenes Answer: c) HACEK group organisms Explanation: HACEK organis...

Multiple Choice Questions (MCQs) on Acute Rheumatic Fever and Group A Streptococcus with Explanations: Question 1: Acute Rheumatic Fever (ARF) is primarily caused by which bacterial species? a) Staphylococcus aureus b) Streptococcus pneumoniae c) Streptococcus agalactiae d) Streptococcus pyogenes (Group A Streptococcus) Answer: d) Streptococcus pyogenes (Group A Streptococcus) Explanation: ARF is primarily caused by Group A Streptococcus (S. pyogenes), particularly following untreated or inadequately treated streptococcal infections. Question 2: Which virulence factor of Streptococcus pyogenes plays a key role in the development of Acute Rheumatic Fever? a) Capsule b) Lipopolysaccharide (LPS) c) M protein d) Teichoic acid Answer: c) M protein Explanation: The M protein on the surface of Streptococcus pyogenes plays a crucial role in molecular mimicry, triggering the autoimmune response responsible for Acute Rheumatic Fever. Question 3: Molecular mimicry in Acute Rheumatic Fever refers ...

Multiple Choice Questions (MCQs) on Eicosanoid Synthesis, Regulation, and Pharmacological Action with Explanations: Question 1: Which enzyme catalyzes the conversion of arachidonic acid to prostaglandin H2 (PGH2) in the cyclooxygenase pathway? a) Lipoxygenase b) Phospholipase A2 c) Cyclooxygenase-1 (COX-1) d) Cytochrome P450 Answer : c) Cyclooxygenase-1 (COX-1) Explanation: COX-1 is responsible for converting arachidonic acid to PGH2, the precursor of various prostaglandins. Question 2: Which class of eicosanoids is involved in promoting vasodilation, relaxation of vascular smooth muscle, and inhibition of platelet aggregation? a) Prostaglandins b) Leukotrienes c) Thromboxanes d) Lipoxins Answer : a) Prostaglandins Explanation: Prostaglandins play roles in vasodilation, relaxation of smooth muscle, and inhibition of platelet aggregation. Question 3: What role do lipoxins play in inflammation? a) They promote inflammation. b) They have anti-inflammatory and pro-resolving effects. c) The...

A. Clinical Case: Altered Cardiac Metabolism in Heart Failure Patient Profile: A 60-year-old male with a history of hypertension presents to the cardiology clinic with complaints of increasing fatigue, shortness of breath, and swelling in the ankles over the past few months. Clinical Presentation: The patient appears fatigued and has difficulty breathing while lying flat (orthopnea). Physical examination reveals elevated jugular venous pressure and peripheral edema. Auscultation of the heart reveals the presence of a third heart sound (S3) and crackles in the lungs. Diagnostic Workup: Echocardiography reveals left ventricular hypertrophy and reduced ejection fraction. Blood tests show elevated levels of B-type natriuretic peptide (BNP). Electrocardiogram (ECG) indicates signs of left ventricular strain. Metabolic Assessment: Blood glucose level: Normal Fasting lipid profile: Elevated triglycerides and low-density lipoprotein cholesterol. Serum lactate: Elevated Blood pH: Slightly acidi...

  A. Clinical Case on Ketosis Patient Profile: A 45-year-old male with a history of type 2 diabetes presents to the emergency department with complaints of increasing weakness, fatigue, excessive thirst, and frequent urination over the past few days. He also reports abdominal pain and a fruity odor on his breath. Clinical Presentation: The patient appears dehydrated and has rapid breathing (Kussmaul breathing). Physical examination reveals dry mucous membranes and tachycardia. The patient's breath has a characteristic fruity odor. Biochemical Investigation: Blood glucose level: 400 mg/dL (high) Arterial blood gas (ABG) analysis: pH: 7.25 (low) pCO2: 20 mmHg (low) HCO3-: 10 mEq/L (low) Serum ketones (beta-hydroxybutyrate): 6.0 mmol/L (elevated) Serum electrolytes: Sodium (Na+): 138 mEq/L Potassium (K+): 4.8 mEq/L Chloride (Cl-): 100 mEq/L Bicarbonate (HCO3-): 10 mEq/L Interpretation and Diagnosis: The elevated blood glucose level (hyperglycemia) and ketones in the blood (ketone...

                            MCQs Iron Metabolism and Anemia 1. What is the primary function of iron in the human body? a) Synthesis of hemoglobin b) Synthesis of vitamin D c) Regulation of blood pressure d) Production of thyroid hormones 2. Which of the following is the storage form of iron in the body? a) Transferrin b) Ferritin c) Hemosiderin d) Hemoglobin 3. Iron absorption is enhanced by the presence of which nutrient? a) Vitamin C b) Vitamin B12 c) Vitamin A d) Vitamin D 4. Anemia of chronic disease is characterized by: a) Elevated transferrin saturation  b) Increased iron absorption c) High serum iron levels d) Low serum ferritin levels 5. Which type of anemia is caused by a deficiency of vitamin B12 or folate? a) Aplastic anemia b) Hemolytic anemia c) Pernicious anemia d) Iron-deficiency anemia 6. Microcytic, hypochromic anemia is typically seen in: a) Aplastic anemia b) Folate deficiency c) Iron-deficienc...