Pace 3 Part 1(Pharmacy)

Explanation
The correct answer is "Actions of cytotoxin and ammonia to damage gastric mucosa." Helicobacter pylori infection can lead to the production of cytotoxins and ammonia by the bacteria, which can damage the gastric mucosa. This damage can result in symptoms such as epigastric burning pains after eating. The other options listed do not directly relate to the damage caused by the cytotoxins and ammonia.

Explanation
The patient's symptoms, including cramps, diarrhea, and greasy floating stools, are consistent with a possible parasitic infection. Collecting a stool specimen for ova and parasites would allow for laboratory testing to identify any potential parasites causing the symptoms. This would help in determining the appropriate treatment for the patient. The other options, such as advising him to avoid certain foods or ordering different tests, may not directly address the underlying cause of the symptoms.

Explanation
Called pork tapeworm, also human tapeworm because human is definitive host. Larval cysts are in pigs
Eggs in human feces infect pigs or infect other humans which develop larval cysts but not adults

2 clinical forms: Adult tapeworm- no symptoms**************
Cysticercosis- brain inflammation
Rarely a human with pork tapeworm can "autoinfect” with eggs and develop cysticercosis

The cyst form (in brain or other ogans) do not produce eggs and therefore do not release ova into the intestine.

Explanation
Caliciviruses (noroviruses)
Caliciviruses are naked, (+) single-stranded RNA viruses. They are roughly 25 nm to 40 nm in diameter and possess an icosahedral symmetry. Two human calicivirus (HuCV) genera belonging to this family are responsible for human gastroenteritis: Norovirus and Sapovirus. Noroviruses (NoV) include the Norwalk (NV) and Norwalk-like viruses (NLV), whereas sapoviruses (SaV) include the Sapporo-like viruses (SLV); all these viruses are currently grouped under the term noroviruses (I mention this because many people use all of these names!). Because these viruses cannot be grown in culture, there are as of yet no serological groupings possible; they are however divided into genogroups (5 NoV genogroups & 5 SaV genogroups) and genotypes. All these viruses present very narrow host specificity (humans; experimental infections in other primates has been difficult).
Noroviruses occur throughout the world and represent 60 to over 90% of non-bacterial gastroenteritis outbreaks (developing & developed world), which occur as outbreaks mostly during the cooler months of the year3. In fact, NoV are the most important cause of waterborne and foodborne diseases. Norovirus infections affect young children and adults alike, normally as community-wide outbreaks. Noroviruses are highly infectious and infections spread very rapidly [secondary contact infection is common (> 50 to 90%)]. Outbreaks also often occur in institutionalized settings (school, day care, hospitals, orphanages, hotels, cruise ships, nursing homes, the military, camps etc.). Transmission occurs primarily through faecal-oral route, although airborne and fomite transmission may also likely occur (being in the same room as someone with projectile vomiting is an important risk factor, and the virus can be recovered from the vomitus).

Contaminated water (drinking, swimming & ice) and food (undercooked shellfish, *****FRUITS & VEGETABLES****, frosting, pasta, sandwiches & cold cuts) are the main culprits so far identified. Viral particles are resistant to a wide variety of detrimental treatments including chlorination, low pH, solvents, heat, cold, ethanol, detergents and quaternary ammonium; they can however be inactivated by glutaraldehyde, iodine-based disinfectants and fresh bleach. Surfaces can be efficiently disinfected using a combination of detergent and bleach.
Norovirus infection spans a wide spectrum of presentations varying from asymptomatic to severe dehydration. When compared with childhood acute gastroenteritis, especially when compared to rotavirus acute gastroenteritis, NoV gastroenteritis usually presents as a milder, self-limiting disease; this is generally (but not always) a distinguishing feature of NoV infection.
****THE INCUBATION PERIOD IS LESS THAN 50 HOURS, FOLLOWED BY A SUDDEN ONSET OF VOMITING AND/OR WATERY DIARRHEA (USUALLY BOTH). STOOLS USUALLY SHOW NO BLOOD, NO MUCOUS AND NO LEUKOCYTES.****
The symptomatic period is short, lasting 1 to 3 days. Other symptoms may include nausea, malaise, abdominal cramps and dehydration; there is usually no fever. As previously mentioned, disease is self-limited. Symptomatic illness is linked with carbohydrate malabsorption and steatorrhea due to a decrease in microvilli enzymatic activity [alkaline phosphatase (regulation of fat absorption; bi-directionnal), sucrase (sucrose  fructose + glucose; leads to malabsorption, gas & diarrhoea) & trehalase (decreased trehalose hydrolysis diarrhoea)], and correlates with blunting and broadening of the intestinal villi, crypt cell hyperplasia, cytoplasmic vacuolization (fat?), as well as polymorphonuclear and mononuclear infiltration into the lamina propria.

Explanation
The correct answer is Anti-HBsAg because it indicates the presence of antibodies against the hepatitis B surface antigen. Hepatitis B virus (HBV) infection is a risk factor for hepatitis D virus (HDV) infection, as HDV requires HBV for replication. Therefore, if the patient had been seropositive for Anti-HBsAg, it would indicate that she had been previously infected with HBV and developed immunity, thus providing complete protection against HDV infection.

Explanation
The peak CTL response is most likely to occur during the fourth week of the hepatitis A infection. This is because the graph shows a steady increase in the CTL response until the fourth week, after which it starts to decline. Therefore, the highest point on the graph is likely to correspond to the peak CTL response, which occurs at week 4.

Explanation
The most likely causative agent in this case is Salmonella typhi. The patient's symptoms of headache, weakness, loss of appetite, and high fever, along with a recent trip to rural India, are consistent with typhoid fever, which is caused by Salmonella typhi. The presence of erythematous, maculopapular lesions on her trunk further supports this diagnosis. The growth of a Gram-negative bacillus on culture, which produces colorless colonies on MacConkey agar and colonies with a black center on Hektoen enteric agar, is also characteristic of Salmonella typhi.

Explanation
The key characteristics of the most likely causative agent in this scenario are anaerobic, sporeforming, and Gram-positive bacillus. This is because the outbreak of gastroenteritis occurred after consuming improperly cooled and reheated food, which is a common cause of foodborne illnesses caused by anaerobic bacteria. Sporeforming bacteria have the ability to survive harsh conditions, such as improper food handling and reheating. Gram-positive bacillus indicates the type of bacterial cell wall composition, which is commonly associated with foodborne pathogens.

Explanation
Reflux esophagitis is the most common cause of esophageal adenocarcinoma in the United States. Chronic gastroesophageal reflux disease (GERD) can lead to the development of Barrett's esophagus, a condition in which the normal lining of the esophagus is replaced by abnormal cells. Over time, these abnormal cells can progress to esophageal adenocarcinoma. This is why the woman is concerned about her risk, as reflux esophagitis is a known risk factor for esophageal adenocarcinoma.

Explanation
The most likely diagnosis in this case is a carcinoid tumor. This is suggested by the strong and diffuse positive staining of the chromogranin stain. Carcinoid tumors are neuroendocrine tumors that commonly occur in the gastrointestinal tract, including the stomach. They can secrete various hormones and bioactive substances, which can cause symptoms such as flushing, diarrhea, and wheezing. The positive chromogranin stain indicates the presence of neuroendocrine cells, which is a characteristic feature of carcinoid tumors. Adenocarcinoma, adenoma, GIST tumor, and lymphoma are less likely based on the staining pattern described.

Explanation
The woman's duodenal biopsy shows villous atrophy and increased intraepithelial lymphocytes, which are characteristic findings of celiac disease. Celiac disease is an autoimmune disorder triggered by the consumption of gluten, a protein found in wheat, barley, and rye. Avoiding gluten in her diet would most improve her symptoms and help her manage her malabsorption.

Explanation
The presentation of bloody diarrhea, weight loss, and patchy areas of ulceration involving multiple parts of the gastrointestinal tract, along with the histological findings of glandular disorder, crypt abscesses, paneth cell metaplasia, and granulomas, are consistent with Crohn's disease. This chronic inflammatory bowel disease commonly affects the terminal ileum and colon, but can involve any part of the gastrointestinal tract. Irritable bowel disease is not a recognized medical condition, Cholera and Escherichia coli infection typically present with watery diarrhea, and Ulcerative colitis primarily involves the rectum and colon without granulomas.

Explanation
The correct answer is Mutation of APC (adenomatous polyposis coli) gene. This is because the patient has multiple colon polyps, which are characteristic of familial adenomatous polyposis (FAP). FAP is caused by a mutation in the APC gene, which is an important tumor suppressor gene involved in regulating cell growth and division. Since the patient's father also had colon cancer at a young age, there is a high likelihood of an inherited genetic mutation. Testing the baby daughter for the APC gene mutation can help determine if she is at risk for developing FAP and colon cancer in the future.

Explanation
The dangerous complication in this case is esophageal malignancy. The patient's symptoms of difficulty in swallowing, along with the presence of anemia and spoon-shaped finger nails, suggest the possibility of an underlying esophageal malignancy. Esophageal malignancy can cause obstruction or narrowing of the esophagus, leading to difficulty in swallowing. The patient's anemia and microcytic hypochromic blood picture may be related to chronic bleeding from the malignancy. It is important to investigate further and confirm the diagnosis to initiate appropriate treatment.

Explanation
Based on the given information, the most likely diagnosis for the 20-year-old woman is irritable bowel syndrome (IBS). IBS is a common gastrointestinal disorder characterized by abdominal pain or discomfort, changes in bowel habits (such as increased frequency or diarrhea), and relief of symptoms after passing stool. The absence of anemia, presence of soft abdomen with slight tenderness to the lower right abdomen, and the absence of other symptoms like vomiting, rectal bleeding, or weight loss suggest a functional disorder like IBS rather than an organic cause like Crohn's disease, ulcerative colitis, small bowel lymphoma, or cancer of the ascending colon.

Explanation
GALLSTONE ILEUS is an important, though infrequent cause of mechanical bowel obstruction, affecting elderly patients who often have other significant medical conditions. It is caused by impaction of a gallstone in the ileum after being passed through a BILIARY-ENTERIC FISTULA. The diagnosis is often delayed since symptoms may be intermittent and investigations fail to identify the cause of the obstruction. The mainstay of treatment is removal of the obstructing stone after resuscitating the patient. Gallstone ileus continues to be associated with relatively high rates of morbidity and mortality.

Explanation
The likely diagnosis in this case is Peutz Jeghers syndrome. This is supported by the patient's presentation of blood mixed with stool, multiple dark pigmentations on the buccal mucosa and lips, and the presence of polyps in the large intestine. Peutz Jeghers syndrome is a rare genetic disorder characterized by the development of hamartomatous polyps in the gastrointestinal tract, as well as mucocutaneous pigmentation. It is associated with an increased risk of developing various types of cancer, including bowel cancer.

Explanation
The most likely diagnosis in this case is congenital pyloric stenosis. The symptoms of projectile non-bilious vomiting, severe vomiting after each feed, and a palpable olive-shaped lump in the upper abdomen are consistent with this condition. Congenital pyloric stenosis is a condition in which the muscle at the outlet of the stomach (pylorus) becomes thickened, leading to a blockage of food from leaving the stomach. This condition is more common in first-born males and can cause dehydration and hunger after vomiting. The mother's history of abdominal surgery in childhood may be a risk factor for the development of pyloric stenosis in the baby.

Explanation
Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal emergencies in the newborn infant. It is a disorder characterized by ischemic necrosis of the intestinal mucosa, which is associated with inflammation, invasion of enteric gas forming organisms, and dissection of gas into the muscularis and portal venous system. Although early recognition and aggressive treatment of this disorder has improved clinical outcomes, NEC accounts for substantial long-term morbidity in survivors of neonatal intensive care, particularly in premature very low birth weight infants (birth weight below 1500 g).

The incidence decreases with increasing gestational age (GA) and birth weight (BW), and is about 6 to 7 percent in infants with very low birth weight (VLBW) infants (BW less than 1500 g)

CLINICAL PRESENTATION — The majority of premature infants who develop NEC are healthy, feeding well, and growing. A change in feeding tolerance with gastric retention is a frequent early sign. The timing of the onset of symptoms varies and appears to be inversely related to gestational age . Overall, 25 percent of cases present later than 30 days after birth. The median age at onset in infants with a gestational age of less than 26 weeks was 23 days, and for those with a gestational age of greater than 31 weeks, the median age at onset was 11 days.

DIAGNOSIS — The diagnosis of NEC is based on the presence of the characteristic clinical features of abdominal distention and rectal bleeding (heme-positive or grossly bloody stools), and the abdominal radiographic finding of pneumatosis intestinalis.

Explanation
INTRODUCTION — Primary biliary cirrhosis (PBC) is characterized by a T-lymphocyte-mediated attack on small intralobular bile ducts. A continuous assault on the bile duct epithelial cells leads to their gradual destruction and eventual disappearance. The sustained loss of intralobular bile ducts causes the signs and symptoms of cholestasis and eventually results in cirrhosis and liver failure.
The signs and symptoms of PBC differ from those of most other liver diseases; thus, the diagnosis may be strongly suspected based upon the clinical findings. As an example, pruritus, hyperpigmentation of the skin, and hepatomegaly in a woman with a cholestatic pattern of liver function tests are common in PBC but unusual in other liver disorders such as acute and chronic hepatitis and alcoholic liver disease
EPIDEMIOLOGY — In contrast to other types of liver disease, 95 percent of patients with PBC are women. PBC is unique among the autoimmune diseases in that it rarely occurs in childhood or before age 30. The onset is usually between the ages of 30 to 65, but the disease has been reported in women as young as 15 and as old as 93. PBC is more common in Caucasian women, but can be seen in other ethnic groups. One study found that disease severity at presentation was higher in non-Caucasians for reasons that were unclear

CLINICAL MANIFESTATIONS AT PRESENTATION — Fatigue and pruritus used to be the most common presenting symptoms of PBC . However, now that the disease is more widely recognized and diagnosed at its earlier stages, approximately 50 to 60 percent of patients are asymptomatic at diagnosis. In series published in the 1970s, for example, up to 78 percent of patients had fatigue at presentation. More recent reports have found that, in newly diagnosed patients, approximately one-half complain of fatigue and one-third pruritus