Basic

A 23-year-old woman with a natural menstrual cycle is nearing ovulation. The oocyte of a mature follicle will be induced to undergo the first meiotic division as a result of which of the following hormonal stimuli?

Cells that form the three primitive germ layers are derived from which of the following?

In the developing human embryo/fetus, most of the internal organs begin to form in which month?

The ectoderm is derived directly from which of the following?

Fetal blood from the placenta is about 80% oxygenated. However, mix- ture with unoxygenated blood at various points reduces the oxygen content. Which of the following fetal vessels contains blood with the highest oxygen content?

Which of the following hematopoietic tissues or organs develops from endoderm?

Which of the following processes places the developing heart in the presumptive thoracic region cranial to the septum transversum?

Which of the following is in direct contact with maternal blood in lacunae of the placenta?

During a visit to her gynecologist, a patient reports she received vita- min A treatment for her acne unknowingly during the first 2 months of an undetected pregnancy. Which of the following organ systems in the developing fetus is most likely to be affected?

The neural plate forms directly from which of the following?

Which of the following forms from paraxial mesoderm?

The cerebral cortex forms from which of the following?

The primordial germ cells that eventually form the oogonia and sper- matogonia originate in which of the following?

Monozygotic twins arise by means of which of the following?

In the developing embryo, the edge of the ectoderm is continuous with which of the following?

Which of the following processes is responsible for fusion of the paired dorsal aortae?

The asymmetry of the cell membrane is established primarily by which of the following?

Which of the following is the function of the large subunit of the ribosome?

The stability and arrangement of actin filaments as well as their prop- erties and functions depend on which of the following?

The primary function of intermediate filaments is which of the following?

Which of the following mechanisms is used to establish the mito- chondrial electrochemical gradient?

Endocytosis of low-density lipoprotein (LDL) differs from phagocytosis of damaged cells in which of the following?

Patients with Cushing’s syndrome often show osteoporotic changes. Which of the following is involved in the etiology of osteoporosis induced by Cushing’s syndrome?

A 5-year-old boy sustains a tear in his gastrocnemius muscle when he is involved in a bicycle accident. Regeneration of the muscle will occur through which of the following?

Which of the following is the primary regulator of salivary secretion?

A 4-day-old boy weighing 7 lb, 6 oz is brought to the emergency room by his parents. The examining emergency room physician notes that his skin and sclerae are icteric. A blood test indicates elevated unconju- gated bilirubin in the serum. The elevated bilirubin levels in this patient are most likely the result of which of the following?

A 43-year-old man who recently returned from a trip to rural Peru presents with severe watery diarrhea, vomiting, and dehydration. He also has marked leg cramps and has lost 8 lb since his return from the trip. Fecal culture is positive for V. cholerae. How does this bacterium exert its effect?

The adrenal cortex influences the secretion of the adrenal medulla by means of which of the following?

A pituitary adenoma is likely to result in which of the following?

Elevated estrogen levels during the menstrual cycle result in which of the following?

Which of the following is independent of testosterone or other androgens?

A 26-year-old woman is in her last trimester of a normal pregnancy. Synthesis of milk by her mammary glands specifically requires which of the following?

In a patient with diabetes mellitus of 30 years’ duration, complica- tions related to kidney function may include which of the following?

Which of the following is found exclusively in the renal medulla?

The retinal pigment epithelium (RPE) is characterized by which of the following?

Which of the following occurs in diabetic retinopathy?

The direction in which vestibular hair cell stereocilia are deflected is important for which of the following reasons?

Perilymph is located in which of the following structures?

Which of the following is the function of the vestibular membrane?

A carcinoma in the medial portion of the lower lip is most likely to first metastasize via which of the following lymph nodes?

Which pair of venous structures contributes to the confluence of dural sinuses on the interior surface of the occipital bone?

Which of the following is the most direct route for spread of infection from the paranasal sinuses to the cavernous sinus of the dura mater?

The course of the vertebral arteries is best described by which of the following statements?

In dislocation of the jaw, displacement of the articular disk beyond the articular tubercle of the temporomandibular joint results from spasm or excessive contraction of which of the following muscles?

Like all endocrine glands, the thyroid is highly vascular. The thyroid gland normally receives its blood supply, in part, from branches off which of the following?

An 85-year old woman comes into your family practice office because she says she is losing weight and she is having trouble chewing. Which of the following muscles is a pure elevator of the jaw?

Pain referred to the right side of the neck and extending laterally from the right clavicle to the tip of the right shoulder is most likely to involve which of the following?

The intercostal neurovascular bundle is particularly vulnerable to injury from fractured ribs because it is found in which of the following locations?

The major venous return system of the heart, the coronary sinus, empties into which of the following structures?

A 36-year-old male office worker comes to the clinic complaining of general weakness and shortness of breath. He also relates a rapid, throbbing pulse after climbing a flight of stairs. Cardiac auscultation reveals a diastolic rumbling murmur attributable to the mitral valve. The mitral valve is best heard where?

The first (S1, or “lub”) heart sound and the second (S2, or “dup”) heart sound originate, respectively, from which of the following?

Structure(s) that normally transit the diaphragm by way of the esophageal hiatus include which of the following?

Gallbladder pain often presents as epigastric pain that then migrates towards the patient’s right side and can even wrap around to the posterior. The referred pain is not the site of the problem. Anatomically where is the gallbladder located?

A 65-year-old male presents with jaundice for 2–3 weeks, fatigue and increasing epigastric pain. He has no history of peptic ulcers and says the pain does not relate to eating in anyway. His epigastric pain is midline and he has had some recent back pain. His urinary bilirubinogen and serum bilirubin are elevated (serum bilirubin 5.8 mg/dl). Helical CT reveals a suspicious mass in the head of the pancreas adjacent to the descending duodenum. The gallbladder is significantly enlarged. Which of the following is the likely cause of the elevated bilirubin?

A full-term male infant displays projectile vomiting 1 h after suck- ling. There is failure to gain weight during the first 48 hours. The vomitus is not bile-stained and no respiratory difficulty is evident. Examination reveals an abdomen neither tense nor bloated. Which of the following is the most probable explanation?

A 19-year-old teenager is brought to the emergency room after a single-car accident just 20 minutes earlier in which she lost control of her car on black ice and hit a retaining column of an overpass at about 45 miles per hour. She was wearing a seat belt but looks pale, has tachy- cardia and positional hypotension, is extremely nauseated, and is lying in the fetal position due to increasingly severe abdominal pain. She has no fractures and a cranial nerve test is normal. You order an abdominal CT because you suspect which of the following?

A 55-year-old woman arrives at the emergency room the day after St. Patrick’s Day coughing up bright red blood. She has frequented your emergency room before. History includes excessive alcohol consumption. Using abdominal percussion you determine that her liver extends 5 cm below the right costal margin at the midclavicular line. You call in a gas- troenterologist because you suspect that the bright red blood is most likely the result of which of the following?

A 24-year old man was a passenger in an automobile broadsided by another vehicle. Although he was wearing a seat belt he felt “terrible,” and had left sided abdominal, flank, and shoulder pain. During the ambulance ride into the emergency room his blood pressure kept dropping, he appeared pale, had a rapid heartbeat, with otherwise normal lung and heart sounds. Intravenous saline was started en route. Which of the following abdominal organs is most likely damaged?

Which of the following is the principal supply to the body and tail of the pancreas?

During the physical exam of a 52-year-old man you note internal hemorrhoids. He complains of blood in his stool. Which of the following arteries could be the source of his rectal bleeding?

Benign prostatic hypertrophy results in obstruction of the urinary tract. Patients present with weak urine flow, increased difficulty initiating urination, and increase frequency of urination since the bladder often is not fully emptied. Benign prostatic hypertrophy is associated with enlargement of which of the following?

Which structure is most susceptible to unintentional damage during a hysterectomy?

Which of the following locations is optimal for fertilization of an ovulated egg by sperm to occur?

An HIV-positive patient asks you if you can tell him the chances of him progressing to symptomatic AIDS. Which one of the following tests would be most useful?

Which of the following viruses causes an acute febrile rash and produces disease in immunocompetent children but has been associated with transient aplastic crises in persons with sickle cell disease?

Infection with herpes simplex virus, a common human pathogen, is best described by which of the following statements?

An HIV-positive patient prior to being treated with AZT, DDI, and saquinavir has a CD4 lymphocyte count and an HIV RNA viral load test done. Results are as follows: CD4: 50 CD4 lymphocytes per microliter, HIV RNA: 750,000 copies per ml. Which of the following statements best describes the above patient?

Infectious mononucleosis, a viral disorder that can be debilitating, is Characterized by which of the following statements?

The clinical picture of arbovirus infection fits one of three categories: encephalitis, hemorrhagic fever, or fever with myalgia. One of the characteristics of arboviruses is that they

Delta hepatitis only occurs in patients who also have either acute or chronic infection with hepatitis B virus. The delta agent is

The most sensitive test for the diagnosis of herpes simplex (HSV) meningitis in a newborn infant is

Mumps virus accounts for 10 to 15% of all cases of aseptic meningitis in the United States. Infection with mumps virus

The serum of a newborn infant reveals a 1:32 cytomegalovirus (CMV) titer. The child is clinically asymptomatic. Which of the following courses of action would be advisable?

A 3-year-old child presents at the physician’s office with symptoms of coryza, conjunctivitis, low-grade fever, and Koplik’s spots. The causative agent of this disease belongs to which group of viruses?

One of the most common sexually transmitted diseases that may lead to cervical carcinoma is caused by which of the following viruses?

Which virus is the leading cause of the croup syndrome in young children and, when infecting mammalian cells in culture, will hemabsorb red blood cells?

Hepatitis E, a recently characterized hepatitis virus, is best described by which of the following statements?

Meningitis is characterized by the acute onset of fever and stiff neck. Aseptic meningitis may be caused by a variety of microbial agents. During the initial 24 h of the course of aseptic meningitis, an affected person’s cerebrospinal fluid is characterized by

Infection with hepatitis D virus (HDV; delta agent) can occur simulta- neously with infection with hepatitis B virus (HBV) or in a carrier of hepati- tis B virus because HDV is a defective virus that requires HBV for its replicative function. What serologic test can be used to determine whether a patient with HDV is an HBV carrier?

Eastern equine encephalitis virus is associated with a high fatality rate. Control of the disease could be possible by eradication of

Adults who have had varicella as children occasionally suffer a recurrent form of the disease, shingles. The agent causing these diseases is a member of which of the following viral families?

German measles virus (rubella), a common cause of exanthems in children, is best described by which of the following statements?

The presence of Negri inclusion bodies in host cells is characteristic of

A hospital worker is found to have hepatitis B surface antigen. Subsequent tests reveal the presence of e antigen as well. The worker most likely

An immunocompromised person with history of seizures had an MRI that revealed a temporal lobe lesion. Brain biopsy results showed multinucleated giant cells with intranuclear inclusions. The most probable cause of the lesion is

An infant, seen in the ER, presents with a fever and persistent cough. Physical examination and a chest x-ray suggest pneumonia. Which of the following is most likely the cause of this infection?

Which one of the following groups of people may be at increased risk for HIV infection?

A patient has all the gastrointestinal symptoms of infection with hepatitis A virus (HAV), yet all the tests for HAV-IgG and HAV-IgM are non- reactive. A possible cause of this infection is

Erythema infectiosum (fifth disease), a self-limited disease of children, is caused by

Which one of the following viruses may be human tumor virus?

Cytomegalovirus (CMV) infection is common. Which one of the fol- lowing statements best characterizes CMV?

There is considerable overlap of signs and symptoms seen in congenital and perinatal infections. In a neonate with “classic” symptoms of congenital cytomegalovirus (CMV) infection, which one of the following tests would be most useful in establishing a diagnosis?

Which one of the following viruses would be most likely to establish a latent infection?

A regimen that includes appropriately administered gamma globulin may be contraindicated in which one of the following diseases?

Atypical lymphocytosis is most likely to be found in which one of the following diseases?

A patient has arthralgia, a rash, lymphadenopathy, pneumonia but no fever. Which of the following diseases is most likely based on these symptoms?

Hepatitis C (HCV) is usually a clinically mild disease, with only minimal elevation of liver enzymes. Hospitalization is unusual. Which one of the following statements best characterizes HCV?

Which of the following markers is usually the first viral marker detected after hepatitis B infection?

Which of the following may be the only detectable serological marker during the early convalescent phase of HBV infection (window phase)?

Which one of the following markers is closely associated with HBV infectivity and DNA polymerase activity?

Which one of the following viruses is the leading cause of congenital malformations?

Orchitis, which may cause sterility, is a possible manifestation of which of the following?

Which of the following is a leading cause of pneumonia primarily in infants?

Which of the following causes a fatal encephalitis for which a vaccine is available?

Traditional vaccination for the common cold is virtually impossible because there are multiple serotypes of which one of the following viruses?

Which of the following is available and effective for hepatitis A?

Patients should be vaccinated annually for influenza with which of the following vaccines?

The vaccine for measles is best characterized as a

Which one of the following would be the treatment of choice for HSV infection?

Which of the following best describes the presently available vaccine for hepatitis B?

Chicken pox is a common disease of childhood. It is caused by which of the following viruses?

Excluding influenza, which one of the following viruses is a common cause of acute respiratory disease?

A vaccine is available for one of the most common causes of infantile gastroenteritis. However, it has recently been recalled. The virus is

A child has mononucleosis-like symptoms yet the test for mononucleosis and the EBV titers are negative. One of the causes of heterophile- negative mononucleosis is

Malaise and fatigue with increased “atypical” lymphocytes and a reactive heterophil antibody test is most commonly caused by

Lethargy, malaise, and fatigue are observed in a patient 2 weeks after eating raw hamburger at a restaurant. The most likely infectious cause is

This virus may be detected by the polymerase chain reaction (PCR) in a variety of cells of patients with nasopharyngeal carcinoma.

What the most appropriate specimen is for the detection of Human papillomavirus

What the most appropriate specimen is for the detection of Cytomegalovirus

What the most appropriate specimen is for the detection of Enterovirus

What the most appropriate specimen is for the detection of Varicella-zoster virus (VZV)

What the most appropriate specimen is for the detection of Adenovirus 40/41

Which of the following is transmitted by the fecal-oral route; can be acquired from shellfish; and often causes acute jaundice, diarrhea, and liver function abnormalities?

Which of the following is the most common cause of pediatric gastroenteritis? It is difficult to grow in cell culture but can be detected easily by immunologic methods (ELISA).

Which of the following is a common cause of epidemic gastroenteritis, particularly aboard cruise ships and in summer camps? It may be detected by ELISA methods or electron microscopy.

Which of the following is a cause of mild gastroenteritis? It can be transmitted by the fecal-oral route but not by food consumption.

IgM antibody to the viral particle is the method of choice for laboratory diagnosis of which one of the following hepatitis viruses?

This virus belongs to the family of flaviviruses and its reservoir is strictly human. Transmission is blood-borne so the blood supply is routinely screened for this virus.

Vaccination for this hepatic disease is with viral surface antigen and usually provides immunity.

This hepatitis virus is a calicivirus. The reservoir is in pigs, and humans acquire it via the fecal-oral route.

This hepatitis virus is a defective virus in that it cannot replicate independently without the presence of hepatitis B virus.

This virus is the leading cause of bronchiolitis and community- acquired pneumonia in infants.

This is a double-stranded DNA virus. It is responsible for 15% of pediatric respiratory infections and 10 to 15% of acute diarrhea in children.

There are millions of cases of leprosy (Hansen’s disease) worldwide, but predominately in Asia and Africa. The clinical spectrum of Hansen’s disease is best characterized by

A 21-year-old college student complained of malaise, low-grade fever, and a harsh cough, but not of muscle aches and pains. An x-ray revealed a diffuse interstitial pneumonia in the left lobes of the lung. The WBC count was normal. The student has been ill for a week.Based on the information given, the most likely diagnosis is

Based on the information given, which of the following laboratory tests would most rapidly assist you in making the diagnosis?

Pathogenic mechanisms involved in tuberculosis can be primarily attributed to which of the following?

Cholera is a toxicogenic dysenteric disease common in many parts of the world. In the treatment of patients who have cholera, the use of a drug that inhibits adenylcyclase would be expected to

Symptoms of C. Botulinum food poisoning include double vision, inability to speak, and respiratory paralysis. These symptoms are consistent with

In people who have sickle cell anemia, osteomyelitis usually is associated with which of the following organisms?

The treatment of choice for a patient with C. Jejuni enterocolitis is

A 28-year-old menstruating woman appeared in the emergency room with the following signs and symptoms: fever, 104°F (40°C); WBC, 16,000/μL; blood pressure, 90/65 mmHg; a scarlatiniform rash on her trunk, palms, and soles; extreme fatigue; vomiting; and diarrhea.The patient described in the case above most likely has

Culture of the menstrual fluid in the case cited would most likely reveal a predominance of

The incidence of H. Influenzae meningitis in the general population is less than 1%. If during an epidemic the incidence rose to 3%, the negative predictive value of the LA test would

A 2-year-old infant is brought to the emergency room with hemolytic uremic syndrome and thrombocytopenia. Which one of the following bacteria would most likely be isolated from a stool specimen?

E. Coli causes disease by a variety of different methods. Which one of the following E. Coli types is characterized by the presence of LT (heat-labile) and ST (heat-stable) proteins?

Human plague can be bubonic or pneumonic. The primary epidemiologic difference between the two clinical forms of plague is

A 2-year-old child was admitted to the hospital with acute meningitis. The Gram stain revealed Gram-positive short rods, and the mother indicated that the child had received “all” of the meningitis vaccinations. What is the most likely cause of the disease?

The most common portal of entry for C. tetani, the cause of tetanus, is the

The most common way in which tuberculosis is acquired is via the

Shigellosis is common in travelers to developing countries. Infection is commonly acquired through the

A person who contracts gonorrhea is most likely to have acquired it via the

The antibiotic of choice for pneumococcal pneumonia is

The antibiotic of choice for streptococcal pharyngitis is

The therapy of choice for pseudomembranous enterocolitis is

V. cholerae, the causative agent of cholera, is best described as

Y. enterocolitica, formerly a Pasteurella, is best described by which of the following statements?

To isolate specific bacteria from clinical specimens, it is necessary to use a variety of artificial media, some of which is selective, others of which are nonselective. N. Gonorrhoeae is a fastidious pathogen and found in sites often con- taminated with normal flora. The best medium for isolation is

V. cholerae, the causative agent of cholera, is best isolated using

M. Tuberculosis can be found in the sputum of patients with tuberculosis. After digestion of the sputum, isolation is best accomplished using

C. Diphtheriae may be difficult to isolate from the nasopharynx with- out the use of special media. The medium of choice is

S. Aureus has a distinctive appearance on which one of the following media?

In order to recognize abnormal bacteria, it is necessary to know which bacteria are predominant normal flora of certain body sites. The bowel contains many microorganisms but the most prevalent bacterium is

Which of the following is the most prevalent microorganism in the vagina that may also be protective?

Influenza can be treated; therefore, specific detection of the virus becomes much more important. Which of the following would be best for detection of influenza?

A bacterium is examined and is found to lack superoxide dismutase, catalase, and peroxidase. Which of the following statements best describes this bacterium?

Analysis of the metabolites produced by an organism’s fermentation of glucose reveals small amounts of 6-phosphogluconic acid. This fermentation organism is most likely to be

Ideally, an antibiotic should focus on a microbial target not found in mammalian cells. By this standard, which of the following antibiotic agents would be expected to be most toxic to humans?

A broad-spectrum antibiotic in the general class of thienamycins is

Third-generation cephalosporin with good activity against Borrelia burgdorferi is

Broad-spectrum penicillin with antipseudomonas activity is

Third-generation cephalosporin with primary activity against Pseudomonas aeruginosa is

Quinolone antibiotic with broad Gram-negative and Gram-positive activity is

Mycoplasmas differ from chlamydiae in that they are

Which of the following mycoplasmas has been implicated as a cause of nongonococcal urethritis (NGU)?

C. Trachomatis can be distinguished from C. Psittaci by which of the following criteria?

Trachoma is one of the leading causes of blindness. Which of the fol- lowing best typifies the disease?

Which one of the following organisms causes primary atypical pneumonia in humans?

Which one of the following organisms is associated with nongonococcal urethritis in humans?

Which one of the following organisms normally inhabits the healthy human oral cavity?

Which one of the following organisms normally inhabits the female genital tract but may cause acute respiratory illness?

Inhalation of fungal spores can cause primary lung infections. Of the following organisms, which one is most likely to be associated with this mode of transmission?

An immunocompromised patient is suspected of having an infection with A. fumigatus. Which of the clinical conditions is most likely to occur?

The diagnostic characteristics of Plasmodium falciparum are best described by which one of the following statements?

The life cycle of this parasite consists of two stages: the cyst and the trophozoite, as shown in the figure below. The most likely identification of this organism is

Human infection with the beef tapeworm, Taenia saginata, usually is less serious than infection with the pork tapeworm, T. solium, because

A survey of 100 healthy adults reveals that 80% have IgG antibodies to Toxoplasma. Which one of the following statements would help to explain this finding?

Analysis of a patient’s stool reveals small structures resembling rice grains; microscopic examination shows these to be proglottids. The most likely organism in this patient’s stool is

Trypanosoma cruzi initially penetrates through the mucous mem branes on the skin and then multiplies in a lesion known as a chagoma. In the chronic stage of the disease, the main lesions are often observed in the

A woman, recently returned from Africa, complains of having paroxysmal attacks of chills, fever, and sweating; these attacks last a day or two at a time and recur every 36 to 48 h. Examination of a stained blood specimen reveals ring-like and crescent-like forms within red blood cells. The infecting organism most likely is

A “parasite” that may be a fungus is the initial clinical manifestation in up to 60% of patients with AIDS. This organism is

Malaria is a significant worldwide public health problem. Which one of the following control methods for malaria is currently effective?

Scabies is caused by a small mite that burrows into the skin. The disease is best described by which one of the following statements?

Amebae that are parasitic in humans are found in the oral cavity and the intestinal tract. Which one of the following statements best describes these intestinal amebae?

Schistosomiasis is a disease characterized by granulomatous reac- tions to the ova or to products of the parasite at the place of oviposition. Clinical manifestations include which one of the following?

Flukes (trematodes) have a great impact on worldwide public health, causing both morbidity and mortality. Which of the following organisms penetrates skin, is endemic in Africa and Latin America, and has a large lateral spine on its eggs?

Which of the following organisms may be ingested with raw fish, affects the liver, and has an operculated egg?

Which of the following organisms penetrates skin, is endemic in Asia, and has a small lateral spine on its eggs?

Which of the following organisms penetrates skin, is endemic in Africa and the Middle East, has large terminal spines on its eggs, and is found in urine samples?

Which of the following organisms penetrates skin, is endemic in Africa and the Middle East, has large terminal spines on its eggs, and is found in urine samples?

A primary procedure for diagnosis of fecal parasites is a stained smear of feces. For some parasitic infections, however, other specimens may be more productive. G. Lamblia is best diagnosed by

E. Histolytica infection is best diagnosed by

The best method for the detection of Strongyloides larvae is

Ascaris are best observed in human specimens by which one of the following?

A butcher, who is fond of eating raw hamburger, develops chorioretinitis; a Sabin-Feldman dye test is positive. This patient is most likely infected with

A fur trapper complains of sore muscles, has swollen eyes, and reports eating bear meat on a regular basis. He is at risk for

A student from Phnom Penh has had abdominal pain for 2 years; he is used to swim in Sekong/Stung Treng river. Which of the following should you be in your differential diagnosis?

A teenager who works in a dog kennel after school has had a skin rash, eosinophilia, and an enlarged liver and spleen for 2 years. The most likely cause of this infection is

Certain parasites are found most commonly in particular body contents. A helminth that is naturally transmitted by ingestion of pork, bear, or walrus meat could be detected in

A tissue-dwelling trematode that may be found in feces can also be detected in

A parasite resembling malaria that infects both animals and humans and is carried by the same tick that transmits B. burgdorferi (the bacterium that causes Lyme disease) would most likely be observed in

Finding HBsAg positive and HBeAg positive reflects

Finding HBsAg positive, HBeAg positive, and IgM core antibody pos- itive reflects

Finding antibodies to HBsAg reflects

The association between low birth weight and maternal smoking during pregnancy can be studied by obtaining smoking histories from women at the time of the first prenatal visit and then subsequently assessing and assigning birth weight at delivery according to smoking histories. What type of study is this?

Which of the following measures is used frequently as a denominator to calculate the incidence rate of a disease?

Among women aged 18 to 34 in a community, weight is normally distributed with a mean of 52 kg and a standard deviation of 7.5 kg. What percentage of women will have a weight over 59.5 kg?

In nine families surveyed, the numbers of children per family were 4, 6, 2, 2, 4, 3, 2, 1, and 7. The mean, median, and mode numbers of children per family are, respectively,

In the study of the cause of a disease, the essential difference between an experimental study and an observational study is that in the experimental investigation

In a study of the cause of lung cancer, patients who had the dis ease were matched with controls by age, sex, place of residence, and social class. The frequency of cigarette smoking was then compared in the two groups. What type of study was this?

The incidence rate of lung cancer is 120/100,000 person years for smokers and 10/100,000 person years for nonsmokers. The prevalence of smoking is 20% in the community. What is the relative risk of developing lung cancer for smokers compared with nonsmokers?

A research team wishes to investigate a possible association between smokeless tobacco and oral lesions among professional baseball players. At spring training camp, they ask each baseball player about current and past use of smokeless tobacco, cigarettes, and alcohol, and a dentist notes the type and extent of the lesions in the mouth. What type of study is this?

You are preparing a report to present to the MoH on the declining rates of gonorrhea in your province in both men and women over the last 10 years. Which type of graph would best illustrate the data?

Select an appropriate measure of frequency that describes the number of deaths in the first 28 days of life per 1000 live births in 1 year.

Select an appropriate measure of frequency that describes the number of deaths under the age of 1 year per 1000 live births in 1 year.

Select an appropriate measure of frequency that describes the number of deaths between the ages of 28 days and 11 months per 1000 live births in 1 year.

Comparison of the prevalence of hepatitis B surface antigen (HBsAg) in medical and dental students. Select an appropriate statistical test to analyze the data that match above description

Death occurs in 10% of cases of meningococcal meningitis. Choose statement below that match rate above.

Approximately 9 people die each year in a country for every 1000 estimated to be alive. Choose statement below that match rate above.

Eighty percent of susceptible household contacts of a child with chicken pox develop this disease. Choose statement below that match rate above.

Children between the ages of 1 and 5 have an average of eight colds per year. Choose statement below that match rate above.

Each individual of the total group has an equal chance of being selected. Select the correct term that match above description of a sampling procedure.

Households are selected at random, and every person in each household is included in the sample. Select the correct term that match above description of a sampling procedure.

A new test for chlamydial infections of the cervix is introduced. Half of the women who are tested have a positive test. Compared with the gold standard of careful cultures, 45% of those with a positive test are infected with chlamydia, and 95% of those with a negative test are free of the infection. Match with the correct percentage with the epidemiologic terms, Sensitivity of the test.

A new test for chlamydial infections of the cervix is introduced. Half of the women who are tested have a positive test. Compared with the gold standard of careful cultures, 45% of those with a positive test are infected with chlamydia, and 95% of those with a negative test are free of the infection. Match with the correct percentage with the epidemiologic terms, Specificity of the test.

A new test for chlamydial infections of the cervix is introduced. Half of the women who are tested have a positive test. Compared with the gold standard of careful cultures, 45% of those with a positive test are infected with chlamydia, and 95% of those with a negative test are free of the infection. Match with the correct percentage with the epidemiologic terms, Prevalence of chlamydial infection in that community. A new test for chlamydial infections of the cervix is introduced. Half of the women who are tested have a positive test. Compared with the gold standard of careful cultures, 45% of those with a positive test are infected with chlamydia, and 95% of those with a negative test are free of the infection. Match with the correct percentage with the epidemiologic terms, Predictive value of a positive test.

A new test for chlamydial infections of the cervix is introduced. Half of the women who are tested have a positive test. Compared with the gold standard of careful cultures, 45% of those with a positive test are infected with chlamydia, and 95% of those with a negative test are free of the infection. Match with the correct percentage with the epidemiologic terms, Predictive value of a negative test

Choose the type of measurement scale for Birth Weight.

Choose the type of measurement scale for Type of medical specialty.

Choose the type of measurement scale for Year of birth.

Which of the following vaccines is CONTRAINDICATED during pregnancy?

A 32yearold 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?

An 18yearold sexually active college student presents with complaints of lower abdominal pain and irregular bleeding for five days. She has no fever. She uses oral contraceptives as method of birth control. Upon examination, the cervix is friable; there is cervical motion tenderness and adnexal tenderness. The pregnancy test is negative. Which is the most likely etiologic agent responsible for these findings?

Which patient is most likely to become a chronic carrier following an acute episode of hepatitis B?

The medical evaluation of a 25yearold intravenous drug user reveals elevated liver enzymes and a positive antiHBsAg. The most likely cause of the abnormal liver profile is hepatitis

The time interval between entry of an infectious agent into a host and the onset of symptoms is called

Rabies, psittacosis, salmonellosis. Select the most common described mode of transmission with the above disease

Measles, tuberculosis, influenza. Select the most common described mode of transmission with the above disease

Select the most effective or principal means of control for Typhoid fever.

Select the most effective or principal means of control for Tetanus.

A 25yearold man presents with blurred vision, dysphagia, and dry mouth. Select the correct etiologic agent that match the descriptions above

A 4yearold girl presents with sore throat, fever, hoarseness, and drooling. Select the correct etiologic agent that match the descriptions above

Which of the following interventions is the most effective in the prevention and control of injuries?

A 52 year old woman presents to your office for her annual gynecological examination. She stopped menstruating about 6 months ago and is getting some hot flashes. Her history reveals that she drinks one glass of wine per day and smokes about 10 cigarettes per day. She does not exercise much and is overweight. Her most important risk factor for developing osteoporosis is

Which of the following types of cancer is the most frequent cause of gynecologic cancer deaths?

A 50 year old woman comes for her periodical health examination. Her body mass index is 29 kg/m2. Her blood pressure is 120/80. She has no family history of cardiovascular disease. Her total cholesterol is 200 mg/dL (5.2 mmol/L), her HDL is 35 mg/dL (0.9 mmol/L), and her LDL is 100 mg/dL (2.6 mmol/L). This patient is at highest risk for developing which of the following conditions?

A 50 year old woman comes for her periodical health examination. Her body mass index is 29 kg/m2. Her blood pressure is 120/80. She has no family history of cardiovascular disease. Her total cholesterol is 200 mg/dL (5.2 mmol/L), her HDL is 35 mg/dL (0.9 mmol/L), and her LDL is 100 mg/dL (2.6 mmol/L). This patient’s weight increases the risk for which of the following cancers?

A 50 year old woman comes for her periodical health examination. Her body mass index is 29 kg/m2. Her blood pressure is 120/80. She has no family history of cardiovascular disease. Her total cholesterol is 200 mg/dL (5.2 mmol/L), her HDL is 35 mg/dL (0.9 mmol/L), and her LDL is 100 mg/dL (2.6 mmol/L). The most appropriate initial intervention for weight loss is

Which of the following is the most important risk factor for developing cervical cancer?

35yearold woman presents to your office complaining of hair loss, bone pain, and dryness and fissures of the lips. She tells you that she has been taking large amount of vitamins in hopes of pre venting cancer and infections. Her symptoms are most likely caused by an excess of

A 20yearold patient presents to the office for contraception counseling. Her history reveals no past medical problems. Her physical and pelvic examination is normal. She is sexually active with the same partner for 9 months. Which of the following contraceptive methods would be most appropriate?

A 30yearold patient presents to your office for contraceptive counseling. She is divorced and has just started a new relationship. She wishes to use oral contraceptives because of their effectiveness. Her examination is normal. Which of the following factors would be considered a contraindication to their use?

The use of oral contracep tives will have the most impact on gynecological mortality by reduc ing the risk for which of the follow ing cancers?

Environmental tobacco smoke (ETS) is a major public health issue, particularly for children. Which of the following conditions is most affected by ETS?

Which of the following groups of risk factors has been associated with endometrial cancer?

Which of the following types of diets may reduce the risk of developing cancer?

A 52yearold patient with chronic cough and shortness of breath is diagnosed with chronic obstructive lung disease. Which of the following factors is the most important contributor to this finding?

Which of the following public health interventions has been the most successful in preventing initiation of smoking or reducing the prevalence of smoking?

Public health efforts to pre vent injuries have been particularly successful in reducing deaths from

Which of the following acts as a cofactor in duodenal ulcer?

A 68yearold man with controlled hypertension complains of gradual impairment of vision. His history further reveals that he was recently diagnosed with mild adult onset diabetes that is also well controlled. He is a retired fisherman. The most likely cause of his visual impairment is

Which of the following is the most cost-effective and safe public health measure today to prevent dental caries?

Dermatitis, diarrhea, and delirium. Select the dietary deficiency that match each set of symptoms and signs.

Edema, neuropathy, and myocardial failure. Select the dietary deficiency that match each set of symptoms and signs.

Treating a pregnant woman infected with syphilis. Select the most appropriate level of prevention that match with description above.