By A. Hamil. Azusa Pacific University.
This interspecies promiscuity is essential to the transmission of this large group of pathogens order fincar 5 mg otc, which can persist in the environment in reservoir hosts purchase fincar 5mg amex, and periodically infect humans when a large group of nonimmune individuals is exposed discount fincar 5 mg visa. Since there are hundreds of asymptomatic or minimally symptomatic infections for every neuroinvasive case, “herd immunity” normally takes over after the infection is present in the environment for a period of time—presumably the reason the incidence of cases has moved like a wave across the United States from east to west since its initial introduction. West Nile is a flavivirus (the family that includes and is named for Yellow Fever virus), a broad group that includes dengue, tick borne encephalitis, Japanese encephalitis, and St. In the Middle East, serologic studies indicate up to 40% of the population has had asymptomatic infection. Disease severity increases with age, with most mortality occurring in individuals over 50. Neuroinvasive disease causes meningitis; a polio-like syndrome of flaccid lower motor neuron–type weakness occurs in about half. Involvement of the brainstem and basal ganglia appears to be common with extrapyramidal syndromes, tremors and ataxia occurring with some frequency. Rabies Fortunately human rabies is extremely rare in the United States, with typically 1 case per year nationwide. However there is a significant incidence among animals, and when human cases occur, there often is some delay in diagnosis, resulting in additional individuals being exposed, and then requiring prophylaxis. Transmission requires transfer of virus-containing secretions or tissue through mucosa or broken skin. Since the virus has an affinity for the muscle endplates, infection is particularly efficient when a bite introduces the virus directly into muscle. Once introduced, virions are transported within axons to the dorsal root ganglion neurons and multiply, then on to the spinal cord and brainstem. Once the virus is in the nervous system, patients develop fever, anxiety, muscle aches, and nonspecific symptoms. Neuropathic symptoms ranging from itching to pain may develop at the inoculation site. In the former, patients develop a Guillain Barre–like picture, with fever, sensory and motor symptoms, facial involvement, and sphincter dysfunction. More common is the encephalitic form in which patients develop inspiratory spasms, precipitated by any Encephalitis and Its Mimics in Critical Care 161 contact with the face, including trying to drink (hydrophobia). Hallucinations and fluctuating consciousness proceed to coma, paralysis, and death within a week. Immunofluorescence can often detect virus in nerve twigs surrounding hair follicles in skin biopsied from the nape of the neck. Despite numerous attempts at treatment, only one or two individuals have survived (24). Confusional states in septic patients—even with sources as localized as urinary tract infections or pneumonia—are so commonplace that clinicians rarely question the underlying pathophysiology. In both, the disorder caused by these intracellular organisms probably is less an encephalitis than an infectious vasculitis. Whether ehrlichia infections have significant neurologic involvement remains unclear—although headaches and alterations of consciousness are described frequently, only a few case reports have described focal brain abnormalities. Organisms can sometimes be identified in buffy coat isolates, using special stains. Legionnaire’s disease similarly does not infect the brain but causes altered cognitive function with remarkable frequency—out of proportion to any associated hypoxia or other metabolic abnormalities. This infection can often be suspected clinically by its multisystem involvement—often with prominent early gastrointestinal symptoms (diarrhea and abdominal pain), bradycardia, and hepatic and renal involvement. Diagnosis typically rests on the combination of rapidly worsening changes on chest radiograms, and either serologic or urinary antigen testing. Signs and symptoms are typically nonspecific—except when a septic embolism causes either a stroke or a mycotic aneurysm that ruptures. Again, findings are typically nonfocal; either on exam or imaging, but cerebral edema can be prominent. Since many of these patients are on chronic immunosuppression, one of the greatest diagnostic challenges can be differentiating between insufficiently controlled lupus or a superimposed opportunistic infection in an immunocom- promised patient. As illustrated in Figure 1, the first step is a clinical assessment, focusing on the history. If neurologic involvement is evident from the outset (seizures, persisting focal deficits), the 162 Halperin Figure 1 Clinical approach to the patient with altered brain function. A general examination should initially focus on vital signs—remembering that fever may not be evident at either end of the age spectrum or in those with compromised immunity. Finally, a limited neurologic assessment, focusing on language, orientation, and cranial nerve function is essential. Key biochemical markers, including glucose, sodium, liver and renal function and, if relevant, blood gases, should similarly be assessed immediately. If none of this reveals significant extra-neurologic disease, focus should shift to the nervous system. If this does not demonstrate significant focal mass effect, and the picture does not clearly suggest a noninfectious cause, a lumbar puncture should be performed. Spinal fluid studies should include cell count, differential, protein, glucose (with simultaneous blood glucose! Blood cultures should normally be obtained as well if there is serious consideration of a nervous system bacterial infection. Initial treatment is often started empirically, depending on context, to cover likely pathogens. However, when encephalitis does occur, its results can be devastating; generally the earlier the treatment can be initiated the better the likelihood of a favorable outcome. Increased cerebrospinal fluid quinolinic acid, kynurenic acid and L-kynurenine in acute septicemia. Recommendations for test performance and interpretation from the Second National Conference on Serologic Diagnosis of Lyme Disease. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America. Cunha Infectious Disease Division, Winthrop-University Hospital, Mineola, New York, and State University of New York School of Medicine, Stony Brook, New York, U.
He does not recall his vaccination history order 5 mg fincar mastercard, normal oropharynx and has a short generic fincar 5 mg with mastercard, squat neck buy discount fincar online. His lung but thinks he has not had any vaccinations since gradu- sounds are clear, and he has a protuberant, obese abdo- ating from high school. He is 190 cm amination, the patient’s wife demands to know what is tall and weighs 95. What are the piratory rate of 14 breaths/min, heart rate of 64 beats/ next steps in diagnosis and treatment? He and his wife should be reassured that his symp- nose, and throat examination reveals no enlargement of toms will improve as his work stress lessens. He should be prescribed a therapeutic trial of No forced expiratory wheezes are present. Which test is most likely to establish the diagno- plaint of cough and dyspnea on exertion that has gradu- sis correctly? Before 3 months ago the patient had no limita- systemic lupus erythematosus except tion of exercise tolerance, but now she reports that she A. A 68-year-old man presents to the emergency room has scattered rhonchi and faint expiratory wheezes bilat- with fever and productive cough. There is associated left-sided pleuritic chest chiectasis to explain his recurrent infections. Positive Gram stain or culture of the pleural ﬂuid chiectasis in a patient with this history. A 45-year-old female is seen in the clinic for evalua- the following is the most common cause of mortality? She reports a cough that began in her early twenties that is occasionally productive of yel- A. Bronchiolitis obliterans innumerable courses of antibiotics, all with brief im- C. Posttransplant lymphoproliferative disorder that she has asthma, and her only medications are ﬂutica- E. A 52-year-old alcoholic man presents to a local cal examination is notable for normal vital signs and an emergency room with purulent, productive cough, short- oxygen saturation of 92% on room air. He lungs have dullness in the upper lobes bilaterally and dif- thinks his symptoms started a few days ago. There is multiple positive cultures for Pseudomonas aeruginosa dullness to percussion over the right lower lung ﬁeld, and and Staphylococcus aureus. A chest radiograph shows eral chest radiography shows bilateral upper lobe inﬁl- a right-sided opacity in the superior portion of the right trates. Which of the following tests is the most important lower lobe with an air-ﬂuid level present. Subsequent management should include scribes the symptoms as “ants crawling in her veins. A 72-year-old male with a long history of tobacco very hot bath to alleviate the symptoms. During sleep, use is seen in the clinic for 3 weeks of progressive dyspnea her husband complains that she kicks him throughout on exertion. She has no history of neurologic or renal dis- anorexia but denies fevers, chills, or sweats. She currently is perimenopausal and has been expe- examination, he has normal vital signs and normal oxy- riencing very heavy and prolonged menstrual cycles over gen saturation on room air. The physical examination, in- normal, and cardiac examination shows decreased heart cluding thorough neurologic examination, is normal. Serum ferritin is 22 nary examination, the patient has dullness over the left ng/mL. Which is the most appropriate initial therapy for lower lung ﬁeld, decreased tactile fremitus, decreased this patient? None of the above have fallen because whenever he tries to read he ﬁnds himself drifting off. Which of the following is the most common under- exercising or brief naps of 10–30 min. Because of this, he lying medical condition of patients undergoing lung states that he takes 5 or 10 “catnaps” daily. Sarcoidosis once weekly, he awakens from sleep but is unable to move for a period of about 30 s. A 34-year-old woman complains of cough produc- of consciousness but states that whenever he is laughing, tive of green sputum, malaise, and headache over the past he feels a heaviness in his neck and arms. She notes that two of her children recently had lean against a wall to keep from falling down. His mean sleep latency on tion, she is afebrile, with a heart rate of 125 beats/min and ﬁve naps is 2. She has pronounced use of her acces- ings of this patient is most speciﬁc for the diagnosis of sory respiratory musculature. Increased risk of lung cancer intensive care unit with pneumonia secondary to Pneu- B. All of the fol- increased incidence of sepsis in the United States except lowing are important supportive measures for this pa- tient except A. A 68-year-old woman is brought to the emergency ment with complaints of 1–2 days of fever, malaise, room for fever and lethargy. Her son feels that He is uncomfortable but alert with temperature of she has had periods of waxing and waning mental status. On examination, she is lethargic breath sounds in the right lower lobe, and chest radio- but appropriate. Piperacillin/tazobactam blood cell count of 24,200/µL with a differential of 82% E. A 68-year-old woman comes to the emergency de- blood cells with gram-negative bacteria on Gram stain.
Adverse effects of isotretinoin include inflammation of mucous membranes (most often the lips) order fincar cheap online, rash purchase fincar 5mg on line, and alopecia cheap fincar 5mg on-line. Reti- noids tend to inhibit lipoprotein lipase, which leads to an increase in serum triglycerides. Acitretin is an oral agent approved for the treatment of psoriasis and other disorders of kerati- nization. In addition, acitretin has been studied in cutaneous T-cell lymphoma and for the pre- vention of skin cancers following solid organ transplantation. It is a topical cream approved for use in the skin disorders associated with Kaposi syndrome. The most common adverse effects seen with tazarotene are skin related: rash, desquamation, and pruritus. Adapalene is a topical retinoid-like drug for the treatment of mild-to-moderate acne vulgaris. Bexarotene is a synthetic oral and topical rexinoid with selectivity for the retinoid X-receptor. It is used in the treatment of cutaneous T-cell lymphoma, Kaposi sarcoma, and breast and lung cancers. Its major adverse effects are hyperlipidemias, both hypertriglyceridemia and hypercholestero- lemia. A 36-year-old woman complains of hot (B) Levonorgestrel flashes, feelings of weakness, and increased (C) Raloxifene appetite. You observe that she is tachycardic (D) Calcitriol and has a prominent pulse pressure. A patient who has recently undergone a kid- Which of the following would be the most ney transplant is immunosuppressed with dexa- appropriate treatment for this patient? Besides the necessary (B) Liotrix treatment of the trauma, which of the following (C) Thyrotropin a actions would be necessary? A male patient is diagnosed with a large, be- formin, but her fasting glucose levels remain nign prostatic mass, and he has the urge to uri- above 100 mg/dL. He returns to your office 3 days (A) Increase insulin secretion later complaining that his urge to urinate has (B) Decrease glucocorticoid levels increased, not decreased. These studies (D) Prostatic resistance to leuprolide indicate an advanced case of osteosarcoma. A 16-year-old female patient enters your der- she becomes unresponsive and moribund. She is electrolytes are normal except for Ca , which is not taking any medications and is well dressed elevated at 4. You diagnose a mild case of acne would be most appropriate choice for treating vulgaris and notice that the girl’s skin and hair this condition? A cab driver with a 10-year history of alcohol- (B) Dihydrotachysterol ism presents with ictarus and yellow sclera; se- (C) Calcitriol rum bilirubin levels are elevated and liver (D) Cholecalciferol function tests are all abnormal. Raloxifene makes hot flashes worse; and while a vitamin D analogue might help maintain Ca2+, it would not have any effect on the vasomotor symptoms. Patients taking glucocorticoids long term have suppressed pituitary–adrenal function and do not respond to trauma with increased cortisol biosynthesis. Isotretinoin is a retinoid that is especially useful in treating acne; it reduces oil production in the skin. Ketoconazole inhibits a number of P-450–catalyzed reactions but not the pro- duction of thyroid hormone. Sulfonylureas such as glyburide increase the release of insulin from the pan- creas. They also may cause an increase in insulin receptors, which increases tissue sensitivity to insulin. They do not slow insulin clearance, and they do not decrease glucocorticoid levels. Thiazides and loop diuretics have opposite effects on Ca excretion; loop diu- retics like furosemide increase Ca2+ excretion and hence reduce hypercalcemia. Calcitriol would be the most effective agent for hypocalcemia in a patient with impaired liver function. The drug of choice is usually the most active drug against the pathogen or the least toxic of sev- eral alternative drugs. An antibacterial agent is often used prophylactically against single microorganisms (e. The choice of drug depends on the effectiveness of host defense mechanisms in controlling the infection. The drug selected for use may be either a bactericidal agent (causing the death of the microorganism) or bacteriostatic agent (temporarily inhibiting the growth of the microorganism). Drug choice is related to the mechanism of drug action in one of the following general categories: a. Host determinants include history of drug reactions; site of infection; renal, hepatic, and immune status; age; pregnancy and lactation; metabolic abnormalities; pharmacokinetic factors; preexisting organ dysfunction; and genetic factors. Bacterial determinants include intrinsic resistance, escape from antibiotic effect, and acquired resistance, which can occur as a result of the following: 1. Spontaneous, random chromosomal mutations, which occur at a frequency of 10–12 to 10–5. These mutations are commonly due to a change in either a structural protein receptor for an antibiotic or a protein involved in drug transport. Conjugation is the passage of genes from bacteria to bacteria via direct contact through a sex pilus or bridge. Conjugation occurs primarily in gram-negative bacilli, and it is the prin- cipal mechanism of acquired resistance among enterobacteria. Structure and mechanism of action (1) Penicillins are analogues of alanine dipeptide (Fig. Modifications of the R-group side- chain (attached to the b-lactam ring) alter the pharmacologic properties and resistance to b-lactamase. Gram-positive bacteria with thick external cell walls are particularly susceptible. The genes for b-lactamases can be transmitted during conjugation or as small plasmids (minus conjugation genes) via transduction. Common organisms capable of producing penicillinase include Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Neisseria gonorrhoeae, and Bacillus, Proteus, and Bacteroides species. Selected drugs and their therapeutic uses (Table 11-1) (1) Penicillin G and penicillin V are mainly used to treat infections with the following organisms (resistant strains of bacteria are being isolated more frequently): (a) Gram-positive cocci (aerobic): Pneumococci, streptococci (except S.
Its one drawback is the susceptibility of the etched surface to saliva or moisture contamination buy fincar 5 mg lowest price, which reduces the bond strength buy fincar 5mg on-line. Salivary contamination results in significantly reduced bond strengths unless removed by thorough washing buy cheap fincar on-line. Re-etching of the surface is usually necessary if salivary contamination has occurred. Bonding agents Bonding agents used as an additional layer under a resin sealant yield bond strengths significantly greater than the bond strength obtained when using sealant alone. Initial results of clinical trials also show increased retention of the sealant when an intermediate bond is used. New bonding techniques are proving to be less technique sensitive, with respect to moisture control than erstwhile procedures. The use of a bonding agent under a sealant on wet contaminated surfaces yields bond strengths equivalent to the bond strength obtained when sealant is bonded directly to clean etched enamel without contamination. Most of the data on the subject of using a bonding agent as part of the sealant procedure supports its use. Use of a bonding agent would tend to increase the time and cost of the sealant application but in cases where maintaining a dry surface is difficult or where there are areas of hypomineralization on the surface, it would have many advantages. Logically, combination of these technologies to achieve better penetration with less steps in the application sequence would be beneficial and there is some evidence already in the use of self-etching primer-adhesive systems. As yet, there has only been a 2-year follow-up but the early results are promising in relation to retention. Other studies have shown that there are concerns about micro-leakage compared with conventional acid etching. The big bonus of the self-etching primer-adhesive system is the speed with which the operator can apply it. In the application procedure for the Prompt-L-Pop system, the operator brushes the self-etching adhesive on to the surface; air thins it, and follows this by immediate placement of the sealant and polymerization. At present, therefore, there are conflicting views on these systems but with technology moving ever onwards it does seem likely that in the future it should be possible to achieve good etching and bonding with a simpler application method. Most clinicians will employ a resin-based sealant, because they have a good track record. Many clinical trials have demonstrated the effectiveness of resin sealants and there are several long-term studies, which show the benefits. Fifteen years after a single application, resin sealants have shown 28% complete retention of sealants and 35% partial retention on first permanent molars. Where researchers re-applied sealant to those surfaces that had deficient sealant as determined by yearly exams, 65% complete retention was obtained and only 13% of the surfaces had caries or restorations after 20 years. Retreatment Sealants placed in the first permanent molars in children of ages 6, 7, and 8 and in second permanent molars in children of ages 11 and 12 required more re-application than those placed in older teeth. If the clinician places fissure sealant in newly erupted teeth it is more likely to fail, but should still be placed as early as possible, because the teeth are more vulnerable to caries at this time. However, fluoride release occurs only for a very short time and at a very low level. Many studies over 2- 3-year periods have reported good retention but with a similar caries incidence to conventional sealant. Since the addition of fluoride to sealant resin does not have any detrimental effect it could certainly be used, but until the chemistry can be adapted to readily unlock the fluoride, the anti-cariogenicity cannot be attributed to the fluoride. Such cements have high levels of fluoride available for release but they suffer from the drawback of poor retention. Even with the very poor retention rates, sealing with glass ionomer does seem to infer some caries protective effect. This may be due to both the fluoride released by the glass ionomer and residual material retained in the bottom of the fissure, invisible to the naked eye. Hence, glass ionomers, used as sealants can be classed as a fissure sealant but more realistically as a fluoride depot material. They can be usefully employed to seal partially erupted molars in high risk children since eruption of the molars takes 12-18 months and during this time they are often very difficult to clean. They are also useful in children where there are difficulties with the level of co-operation, as the technique does not depend on absolute moisture control. As yet, studies of these materials used as fissure sealants while available, show no improvement over resin-based sealants and so there is nothing to recommend them in preference to resins. Retention is better for unfilled resins probably because it penetrates into the fissures more completely. If a filled resin is not adjusted there is a perceptible occlusal change, possible discomfort, and wear of the opposing antagonist tooth. It has been found that identification error for opaque resin was only 1% while for clear resin the corresponding figure was 23% with the most common error being false identification of the presence of clear resin on an untreated tooth. The disadvantage of opaque sealant is that the dentist cannot examine the fissure visually at future recalls (Figs. Safety issues There has only been one report of an allergy to the resin used for pit and fissure sealing and concern has been raised about the oestrogenicity of resin-based composites. The amount released orally is undetectable in the systemic circulation and concerns about potential oestrogenicity are probably unfounded. Sealant bulk in relation to application It is important to remember that the sealant must be kept to a minimum, consistent with the coverage of the complete fissure system including buccal and lingual pits. Sealant monitoring Once the sealant has been placed the operator must monitor it at recall appointments and repair or replenish as necessary. This leaves that surface equally at risk from caries compared to an unsealed surface. Cost-effectiveness Cost-effectiveness will depend on the caries rate for the children in the population. Where there is a higher caries rate, generalized sealing will protect more surfaces that would have become carious in the future. However, if the caries rate is very high, then the risk of developing interproximal lesions is also higher and may lead to a two surface restoration even when the fissure sealed surfaces remain caries free. Sealing over caries Once caries has been diagnosed it is important to determine its extent. If there is clear unequivocal evidence that the lesion does not extend beyond the enamel, then the surface may be sealed and monitored both clinically and radiologically. However, several authors have shown that dentinal carious lesions do not progress under intact sealants.
Also the Gaussian curve shows that half of the measurements are below the mean value cheap generic fincar canada, and the other half are above it order 5mg fincar. The standard deviations in radioactive measurements indicate the statistical ﬂuctuations of radioactive decay proven 5mg fincar. For practical reasons, only single counts are obtained on radioactive samples instead of multiple repeat counts to determine the mean value. In this situation, if a single count n of a radioactive sample is large, then n can be estimated as close to ;n that is, n = n and s = n. It can then be said that there is a 68% chance that the true value of the count falls within n ± s or that the count n falls within one standard deviation of the true value (Fig. That is, one is 68% conﬁdent that the count n is within one standard deviation of the true value. Similarly, 95% and 99% conﬁdence levels can be set at two standard deviations (2s) and three standard deviations (3s), respectively, of any single radioactive count. Another useful quantity in the statistical analysis of the counting data is the percent standard deviation, which is given as s 100 n 100 %s 100 (4. Thus, the precision of a count of a radioactive sample can be increased by accumulating a large number of counts in a single measurement. Answer 95% comﬁdence level is 2s, that is, 2 n 2s × 100 2 n × 100 2% = = n n Therefore, 200 2 = n n = 100 n = 10,000 counts Propagation of Errors 37 Standard Deviation of Count Rates The standard deviation of a count rate is s sc = t where s is the standard deviation of the total count n of a radioactive sample obtained in time t. Because n is equal to the count rate c times the counting time t, c sc n t ct t (4. Answer 8640 Count rate c 720 counts per minute cpm 12 Standard deviation, sc ct 720 12 8 Therefore, the count rate is 720 ± 8cpm. Propagation of Errors Situations arise in which two quantities, say x and y, with their respective standard deviations, sx and sy, are either added, subtracted, multiplied, or divided. The standard deviations of the results of these arithmetic opera- tions are given by the following expressions: Addition: s (4. Calculate the net count rate, its standard deviation, and percent standard deviation. Answer 8000 Gross sample count rate 1600cpm 5 3000 Background count rate 600cpm 5 Net count rate = 1600 − 600 = 1000cpm Using Eqs. The 2-min counts are: standard, 90,000; room background, 1000; thyroid, 40,000; and thigh, 2000. Answer Net standard count = 90,000 − 1000 = 89,000 s s 90,000 1000 = 302 Chi-Square Test 39 Net thyroid count = 40,000 − 2000 = 38,000 st 40,000 2000 = 205 Percent thyroid uptake 38,000 = 100 42 7. It should be noted that although all counts were taken for 2min, count rates (cpm) were not used in the calculations. Chi-Square Test 2 The chi-square (c ) test is a useful test for verifying if the variations in a set of measurements are due to statistical randomness of the data or due to variations in entities, such as equipment, patients, and the like, used in the measurements. The latter variations may be systematic, such as a ﬁxed voltage drop throughout the measurement or random, such as ﬂuctuations in voltage supply to the equipment. If there are N measurements made of a parameter, then for Gaussian distribution of the data, which is true in radioactive measurement, the c2 is given by N 2 i − c = ∑ (4. If the observed c2 value falls outside this range, it is an indication that the variation is beyond the statistical randomness of the data and something is wrong with the experimental set-up, for example, measuring equipment, measurement technique, and so on. In performing the c2 test, a number of measurements (a minimum of 10) are made of the quantity, and the mean and c2 of the measured values are 2 calculated by Eq. Use the c2 test to see if the variations in counts are due to statistical variations of radioactivity or the counter is not working properly. The computed c2 far exceeds the theoretical value, so something in addi- tion to the statistical ﬂuctuations of the counts is operating. Minimum Detectable Activity The efﬁciency of different detectors is limited by the dead time at high count rates and by statistical ﬂuctuations at low count rates of the back- grounds. Evaluation of Diagnostic Tests It is often required to evaluate the usefulness of a new diagnostic test to determine the presence or absence of a particular disease. This aspect of the test is commonly described by two entities: sensitivity and speciﬁcity. The sensitivity of a test is the probability of being able to identify correctly 42 4. By these deﬁnitions, it is obvious that a given test may not identify all patients correctly whether or not they have the disease. It should be noted that when sensitivity is assessed for a diseased popu- lation or speciﬁcity for a healthy group, the disease or healthy status of the group must be assessed by an established standard diagnostic test. This test is called the “gold standard” and is considered the best method available for comparison. Suggested Readings 43 Answer True positive = 780 True negative = 160 − 15 = 145 False negative = 840 − 780 = 60 False positive = 15 780 780 Sensitivity = 100 92 6. A radioactive sample gives 15,360 counts in 9min: (a) What are the count rate of the sample and its standard deviation? How many counts of a sample are to be collected to have a 1% error at the 95% comﬁdence level? To achieve an estimated percent standard error of 3%, how many counts must be collected? What is the prob- ability that the variations of measurements are due to statistical varia- tions of the quantity? The majority of radionuclides are arti- ﬁcially produced in the cyclotron and reactor. Some short-lived radionu- clides are available from the so-called radionuclide generators in which long-lived parents are loaded and decay to short-lived daughters. These accelerated particles can possess a few kiloelectron volts (keV) to several billion electron volts (BeV) of kinetic energy depending on the design of the cyclotron. Because charged particles move along the circular paths under the magnetic ﬁeld with gradually increasing energy, the larger the radius of the particle trajectory, the higher the kinetic energy of the particle. The charged particles are deﬂected by a deﬂector (D) through a window (W) outside the cyclotron to form an external beam.
He reports tion that extends past the left common carotid ar- that over the past 2 weeks fincar 5mg discount, he has developed his typical an- tery after an automobile accident ginal symptoms of chest pressure radiating to his jaw and C 5mg fincar amex. A 42-year-old male with Marfan’s syndrome with a left arm with progressively less exertion buy genuine fincar line. He has been using distal aortic dissection beginning just below the left sublingual nitroglycerin more frequently. His other medi- subclavian artery and an aortic root of 53 mm cation includes a beta blocker, aspirin, and lovastatin. A 56-year-old male with a descending aortic dissec- for a blood pressure of 140/88 mmHg; a heart rate of 110/ tion that encompasses the origin of the renal and il- min, and a respiratory rate of 25/min. He has bilateral iac arteries with rest claudication crackles halfway up both lung ﬁelds and has a 3/6 systolic murmur that radiates to his axilla. The pulmonary, abdominal, ex- drome and narrow complex tachycardia tremity, and neurologic examinations are normal. A 28-year-old male with known preexcitation syn- echocardiogram demonstrates a normal ejection frac- drome and wide complex tachycardia tion without an effusion. What is the prior history of heart disease most appropriate treatment for this patient? His care provider is measurements concerned about pneumonia, so a chest radiograph is B. On the chest radiograph, the aorta appears tor- and stent tuous with a widened mediastinum. Consult interventional radiology for placement of ing hit in the chest with a ball while playing lacrosse. A 44-year-old woman presents to the emergency The murmur is best heard at the lower left sternal bor- room complaining of acute onset of chest pain. The murmur does not radiate describes the chest pain as 10/10 in intensity, with a to the neck. With passive elevation of the legs, the mur- lying ﬂat and better when sitting upright. Tricuspid regurgitation decrease in macrovascular complications (coronary ar- tery disease, stroke) in patients with diabetes and dyslipi- V-104. Insulin resistance and fasting hyperglycemia are im- demia except portant when creating a treatment program for the meta- A. Metformin is more effective than the combination of weight reduction, dietary fat restriction, and in- V-108. Pulsus paradoxus can be described by which of the creased physical activity for the prevention of diabe- following statements? Metformin is superior to other drug classes for in- asthma exacerbations in which the negative intra- creasing insulin sensitivity. Thiazolidinediones, but not metformin, improve in- with a resultant increase in systolic pressure during sulin-mediated glucose uptake in muscle. Pulsus paradoxus has not been described in patients ducing the incidence of diabetes mellitus. Pulsus paradoxus describes the ﬁnding of dimin- myopathy is offered a heart transplant from a 20-year-old ished pulses during inspiration, when the peripheral female with brain death after a skiing accident. A drop in systolic pressure during inspiration of vised about if he decides to accept the heart? Risk of rejection of transplanted organ when there is an exaggeration of the normal decrease C. A 35-year-old woman is admitted to the hospital with malaise, weight gain, increasing abdominal girth, V-106. The swelling in her legs has gotten baseline, his exercise tolerance is normal, but he has lim- increasingly worse such that she now feels her thighs are ited his activity in the past few days due to fear of exacer- swollen as well. She was treated at that time with normal blood pressure, heart rate is 104 beats per chemotherapy and mediastinal irradiation. On physical minute, respiratory rate 22 breaths per minute; oxygen examination, she has temporal wasting and appears saturation 91% on room air. The sound is short and abrupt and is heard lar hypertrophy, and T-wave inversions in V2 and V3. A strong parental history of sudden cardiac death as room complaining of shortness of breath, chest pain, and a presenting history of coronary artery disease in- dizziness. An estimated 50% of all cardiac deaths are sudden aspirin and lay down, but the symptoms worsened. As many as 70–75% of men who die of sudden car- called 911, and upon arrival to the emergency room, he diac death have evidence of acute myocardial infarc- was found to be hypotensive and tachycardic. On physical examination, he survival rates are no better than 25–30% in the out- appears in distress and is diaphoretic. A 64-year-old man suddenly collapses while playing sounds are regular and tachycardic. Initial rhythm on cardiac monitor is ven- Emergency cardiac catheterization is scheduled, and it is tricular ﬁbrillation. What is the ﬁrst step in the treatment estimated that the catheterization laboratory will be of this patient? The patient remains hypotensive with a blood pressure that is now 68/38 mmHg, and the A. What is a full 5 min prior to attempting deﬁbrillation the best management for the patient’s hypotension? A 64-year-old woman is admitted to the emer- strated to improve survival to hospital discharge with fa- gency room with hypotension and chest pain. Her vorable neurologic outcome in out-of-hospital cardiac symptoms began 30 min ago, awakening the patient arrest? Given is sinus with occasional premature ventricular contrac- the characteristics of his chest pain, it is decided that he tions. He has a history of shows normal left ventricular function and right ven- myocardial infarction involving the left anterior descend- tricular dilatation. What is the best immediate treat- ing artery 2 years ago, for which he received reteplase with ment for this patient’s hypotension? You are called to the bedside to see a patient with 99m nuclear stress test is shown in Figure V-115 (Color Prinzmetal’s angina who is having chest pain. Reversible ischemia of the anteroapical wall lowing additional disorders is the patient most likely to D. A 56-year-old man is admitted to the hospital for history is remarkable for early coronary artery disease in newly diagnosed heart failure.