Correct Answer: A

Rationale: Contact isolation prevents the transmission of Clostridium difficile spores, a significant source of nosocomial infections. Private rooms reduce cross-contamination risks. Antidiarrheal use is contraindicated in Clostridium difficile infection as it may worsen colitis by retaining toxins. Prompt stool elimination is vital. Antibiotics are used to treat Clostridium difficile but educating the patient about antibiotic cessation is inappropriate as their use is essential for infection control. Stool softeners are unnecessary since diarrhea is already present, and further softening may exacerbate fluid and electrolyte loss.

Correct Answer: B

Rationale: While alcohol is a known irritant to the gastric lining, it is not the primary cause of peptic ulcer disease. Excessive alcohol consumption contributes to mucosal damage but lacks the direct causative action of Helicobacter pylori, which colonizes the stomach lining and interferes with protective mechanisms, leading to ulcer formation. Alcohol merely exacerbates existing risk factors rather than initiating disease. Helicobacter pylori is the most common cause of peptic ulcer disease globally. Its mechanism involves producing urease, neutralizing stomach acid and enabling bacterial survival. It induces inflammation and mucosal damage, compromising the stomach's protective lining. Persistent infection leads to ulcer formation. This bacterial colonization is implicated in up to 90% of duodenal ulcers, making it the key pathogenic factor in PUD. Smoking is a risk factor for peptic ulcer disease but functions more as an aggravating agent than the primary cause.
Tobacco use increases gastric acid secretion and decreases bicarbonate production, weakening mucosal defenses. It also reduces the efficacy of Helicobacter pylori eradication therapy, prolonging ulcer disease. However, it does not directly induce the condition independently, highlighting its secondary role in PUD pathology. Stress is associated with peptic ulcer disease but is not a primary causative factor. Psychological stress can lead to hypersecretion of gastric acid, aggravating mucosal vulnerability in susceptible individuals. However, its role is predominantly indirect, amplifying existing risk factors like Helicobacter pylori infection. Stress-induced ulcers are typically seen in critical illnesses or severe physiological stress conditions, differing from PUD pathogenesis.

Correct Answer: A:D,B:B,C:E,D:A,E:C

Rationale: Osteomalacia matches choice D: It is caused by a vitamin D deficiency, leading to reduced calcium absorption, softening bones, and increasing fracture risk, uncommon in developed countries due to dietary fortification. Low back pain matches choice B: It is commonly due to musculoskeletal issues like muscle strain or disc problems and can present as localized or diffuse pain. Osteomyelitis matches choice E: It is a severe bacterial infection affecting bone and surrounding tissues, often requiring prolonged antibiotic therapy. Osteoporosis matches choice A: It is a chronic condition characterized by low bone mass and structural deterioration, increasing fragility and fracture risk, especially in postmenopausal women. Degenerative disc disease (DD
D) matches choice C: It involves age-related loss of disc fluid, reducing elasticity and shock absorption, contributing to back pain and spinal issues.

Correct Answer: A

Rationale: Contact isolation prevents the transmission of Clostridium difficile spores, a significant source of nosocomial infections. Private rooms reduce cross-contamination risks. Antidiarrheal use is contraindicated in Clostridium difficile infection as it may worsen colitis by retaining toxins. Prompt stool elimination is vital. Antibiotics are used to treat Clostridium difficile but educating the patient about antibiotic cessation is inappropriate as their use is essential for infection control. Stool softeners are unnecessary since diarrhea is already present, and further softening may exacerbate fluid and electrolyte loss.

Correct Answer: A

Rationale: X-rays are commonly used to diagnose osteoarthritis as they effectively visualize joint space narrowing, osteophyte formation, and subchondral sclerosis, which are characteristic of OA. These imaging findings assist in confirming the diagnosis and assessing disease progression. Lithography is not a diagnostic tool used for OA. It primarily refers to a printing method and has no relevance to imaging joints affected by osteoarthritis or diagnosing the condition scientifically. Ultrasound can visualize soft tissues but is not routinely used for OA diagnosis. It does not provide the detailed assessment of joint degeneration seen in X-rays, making it less appropriate for identifying OA-related changes. Echocardiograms are used to assess heart function and have no application in diagnosing osteoarthritis. They are irrelevant in imaging joint structures or evaluating degenerative joint diseases scientifically.