By G. Mazin. University of Texas at Brownsville. 2017.
Which of the following statements regarding the pathophysiology of benign prostatic hyperplasia (BPH) is true? The hyperplastic process of BPH begins in the peripheral zones and can eventually compress the urethra B purchase suhagra 100mg without a prescription. Only one type of alpha2-adrenergic receptor has been identified in the lower urinary tract C purchase 100 mg suhagra amex. Type 1 5α-reductase isoenzyme converts testosterone to dihy- drotestosterone preferentially in the prostate D. Peptide growth factors such as fibroblast growth factors, insulinlike growth factors, and epidermal growth factors are felt to be the local forces that determine prostate growth Key Concept/Objective: To understand the basic pathophysiology involved in BPH BPH involves hyperplasia of both the epithelial and the stromal compartments. The hyperplastic process begins in the periurethral and transition zones of the prostate; in contrast, prostate cancer preferentially develops in the peripheral zones. At least three types of alpha2-adrenergic receptors have been identified in the lower urinary tract. The type 1 5α-reductase isoenzyme has low activity in the prostate and is expressed pre- dominantly in the skin and liver. The pathophysiologic mechanisms underlying the development and progression of BPH are incompletely understood. Clearly, BPH involves prolonged exposure of the prostate gland to androgens. In the prostate, inter- actions between epithelial and stromal cells and the extracellular matrix, mediated pri- marily by locally produced (intrinsic) growth factors, appear important. These peptide growth factors, which include fibroblast growth factors, insulinlike growth factors, and epidermal growth factors, are felt to be the local forces that determine prostate growth. A 57-year-old man presents for evaluation of urinary frequency. On review of symptoms, the patient also reports occasional hesitancy and dribbling. Results of physical examination, including digital rectal examination, are normal. Which of the following statements regarding the diagnosis of BPH is false? Systemic diseases that can mimic BPH include diabetes, heart fail- ure, and hyperparathyroidism B.
HIV-seropositive patients with a PPD of 5 mm or greater should receive 9 to 12 months of INH chemoprophylaxis 100 mg suhagra otc. Patients younger than 35 years with a recent PPD conversion of 10 mm or greater and patients older than 35 years with a 15 mm PPD conversion are candidates for chemoprophy- laxis generic suhagra 100 mg line. Several other factors lower the threshold for chemoprophylaxis, including recent exposure, an abnormal chest x-ray consistent with old TB, and membership in high- incidence population groups (e. INH chemoprophylaxis is no longer administered for 1 year; therapy for 6 to 9 months achieves the best balance between reducing the risk of active TB and minimiz- ing the risk of hepatitis. Rifampin and pyrazinamide for 2 months can be substituted for INH chemoprophylaxis in patients who are unable to take INH or in whom INH resistance is suspected. A 48-year-old physician from New York City develops fever, night sweats, cough, weight loss, and malaise. Chest x-ray reveals an infiltrate in the posterior-apical segment of the right upper lobe. Which of the following treatment options would you institute for this patient at this time? Await cultures and sensitivity testing before instituting therapy B. INH, rifampin, ethambutol, pyrazinamide, and streptomycin Key Concept/Objective: To understand the treatment of active tuberculosis 7 INFECTIOUS DISEASE 13 This patient has a clinical syndrome very suggestive of tuberculosis. He is smear-posi- tive, and treatment should be initiated immediately, pending the results of mycobacte- rial culture and antimicrobial sensitivity. He should be hospitalized and placed in a neg- ative-pressure isolation room for induction of chemotherapy until his symptoms improve and he becomes smear-negative. The United States Public Health Service rec- ommends initiation of therapy with INH, rifampin, ethambutol, and pyrazinamide unless the INH-resistance rate in the community is low (< 4%), in which case ethamb- utol can be withheld. In drug-sensitive cases, treatment is then changed to INH and rifampin for an additional 4 months (until spu- tum cultures have been negative for at least 3 months).
Henceforth buy discount suhagra 100 mg online, the medial shift velocity increased generic 100mg suhagra amex, reaching a maximum at 90° of knee ﬂexion. Then, the varus velocity increased, reaching a maximum between 40 and 50° of knee ﬂexion; henceforth, the velocity decreased reaching zero between 60 and 65° of knee ﬂexion. The valgus velocity increased again achieving a maximum around 80° of knee ﬂexion. Then, the external rotation velocity began to increase reaching a maximum at around 8° of knee ﬂexion and decreased, reaching zero around 20° of knee ﬂexion. From this point, the internal rotation velocity increased to a maximum between 45 and 60° of knee ﬂexion then decreased as the knee ﬂexion increased. The remaining results related to contact and ligamentous forces are shown for pulses of different amplitudes and a constant duration of 0. These two ﬁgures show that increasing the pulse amplitude caused a decrease in the magnitude of the medial and lateral contact forces; similar results were obtained when the pulse duration was increased while the pulse amplitude was kept unchanged. As the ﬂexion angle increased, this tension decreased while tension in the anterior ﬁbers increased and became dominant. The maximum forces in the anterior and deep ﬁbers occurred between 40 and 50° of knee ﬂexion, while the maximum force in the oblique ﬁbers occurred at approximately 5° of knee ﬂexion. The results show that the patterns of change in the ligamentous forces were not generally affected by changing the characteristics of the applied pulsing loads. However, increasing pulse amplitude (and/or duration) slightly affected the magnitude of the forces in the different ligamentous ﬁbers. The procedure is then repeated at different positions to cover a range of knee motions. However, these quasi-static models cannot predict the velocity or acceleration of the different segments forming the joint. Also, these models are further limited in that they cannot determine the effects of the dynamic inertial loads (which occur in many daily living activities) on joint kinematics and joint loads. In this chapter, a © 2001 by CRC Press LLC FIGURE 1.
The release of the drug from the coating must be coordinated with the intended biological targets suhagra 100mg overnight delivery, which may be upregulated anywhere from minutes to weeks after the stent implantation procedure generic suhagra 100mg with mastercard. The coating must survive several physical challenges. The coating must also not interfere with the primary function of the stent, which is to physically support the walls of the blood vessel. There are several ways to prepare drug delivery coatings and to control the release of a drug from the stent surface. The method SurModics has employed is to form coatings using combinations of nonbiodegradable polymers and drug, with the objective of achieving a homoge- neous mixture on the surface of the stent. The release of the drug is controlled by the loading of the drug and the composition of the polymer components, both of which influence the rate at which the drug diffuses out of the coating. Additional control of the release can be achieved by applying barrier coatings onto the surface of the drug-containing polymer layer. As an example of the work done at SurModics with drug delivery coatings, we will describe examples involving several model drug compounds. Due to proprietary constraints, these drugs will not be named. Polymer coatings containing drug were prepared by depositing films on stainless steel disks or laser-cut, stainless steel, balloon-expandable stents. Coating solutions were prepared using a blend of two polymers, polyethylenevinylacetate and polybutylmethacry- late (PEVA and PBMA), and drug. The concentrations of components (polymers and drug) were varied to obtain different loading levels of drug, different ratios of drug to polymer, and different ratios of the polymer components. The coatings were investigated using several types of surface analytical techniques. Optical microscopy and scanning electron microscopy were used to assess uniformity and surface texture of coatings. Raman IR spectroscopy was used to obtain spatial information on the chemical composition of the films, including location and relative concentration of polymer and drug components. The surfaces of most of the drug-containing coatings were smooth when viewed under the visible microscope (Fig.