Intra-operative frozen section technique for pituitary adenomas.

Orange G-hematoxylin stains performed on frozen sections from the sella turcica had a diagnostic accuracy of over 90% when compared to permanent sections on the same tissue. This technique allows the pathologist to make an intra-operative contribution to the establishment of tumor margins in the selective removal of pituitary adenomas.     

Genitourinary issues in the male college student: a case-based approach

Five percent of all ambulatory visits by men 18 years of age or older include genitourinary symptoms as a reason for the visit. In this article, using typical, unusual, or otherwise instructive cases, the authors review a select group of genitourinary issues in the college-age male. Warts (human papilloma virus), is the most common sexually transmitted infection, and it may mimic other disease. Testicular cancer is one of the most serious diseases to confront health care providers. Varicoceles are the most common scrotal mass. Urethritis is a common presentation of sexually transmitted infection in the young adult male. Acute prostatitis is an unusual condition in the young adult, but it is easily treatable. Sexual dysfunction causes great distress in the young adult, but a systematic approach usually leads to a treatable psychological or environmental cause. With understanding of these medical conditions, the practitioner should feel comfortable addressing the most challenging genitourinary health needs of this population.     

Impact of Carotid Artery Angioplasty and Stenting on Management of Recurrent Carotid Artery Stenosis

Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of the carotid artery (CAS) has been advocated for recurrent carotid stenosis (RCS). To examine the impact of CAS on the management and outcome of recurrent stenosis, a retrospective review of a prospectively compiled database was performed. From a registry of patients treated for carotid disease, 105 procedures were performed from 1992 to 2002 for RCS. For comparison, two study groups were examined. Time I consisted of 77 reoperations performed through 1998, before CAS was introduced at our institution. Time II included 12 reoperations and 16 CAS procedures performed for RCS from 1999 through 2002. Using perioperative stroke as a measure of outcome, the results for time II were poorer than for time I (7.2% vs. 5.2%, p = NS). Overall, the risk of perioperative stroke was the same for reoperation (5/89) and CAS (1/16) (5.6% vs. 6.3%, p = NS). Although not statistically significant, there was a trend toward a higher risk of perioperative stroke for patients treated with reoperation during the latter time period (8.3% vs. 5.2%, p = NS). This probably relates to the finding that during time II, CAS was most likely to be used in asymptomatic patients (68.6% vs. 41.7%, p = NS) with early (<3 years) RCS (87.5% vs. 41.7%, p = 0.01). No patient with asymptomatic, early RCS had a perioperative stroke with either surgery or CAS (0/35 cases, 0%). The presence of preoperative neurologic symptoms was significantly predictive of a perioperative stroke among all procedures performed for RCS (13.6% vs. 0%, p = 0.004). Contrary to suggestions that CAS might improve the management of RCS, a review of our data shows the overall risk of periprocedural stroke to be no better since CAS has become available. The bias for using CAS for asymptomatic myointimal hyperplastic lesions, and reoperation for frequently symptomatic late recurrent atherosclerotic disease, makes direct comparisons of the two techniques for treating RCS difficult. It is expected that the overall risk for redo carotid surgery will increase, as fewer low-risk patients will be receiving open procedures. However, the increased risk among symptomatic patients undergoing reoperation suggests that endovascular techniques should be investigated among this group of cases as well.Presented at the Twenty-eighth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago, IL, June 7, 2003.     

Activation kinetics of the slow afterhyperpolarization in hippocampal CA1 neurons

The activation of the slow afterhyperpolarization (sAHP) in CA1 neurons was studied using whole-cell recordings in the presence of inhibitors of the fast and medium-duration AHPs. The amplitude of the slow afterhyperpolarization current (IsAHP) increased as a function of duration and magnitude of the depolarizing voltage pulse reflecting graded increases in Ca²⁺ influx through voltage-dependent Ca²⁺ channels. Therefore, the time constant for activation, _max, determined from a family of IsAHPs as a function of pulse duration, was voltage dependent decreasing several-fold within the range of –20 to 20 mV and was dependent on extracellular [Ca²⁺]. The IsAHP displayed a pronounced rising phase that was well fit by a single exponential with a time constant, _rise, that was invariant of pulse duration, voltage, IsAHP amplitude, or external [Ca²⁺] and was significantly slower than the _max. In current clamp, the magnitude of the sAHP increased with the number of evoked action potentials, yet _rise of the sAHP was invariant of action potential number and was similar to the _rise of the IsAHP recorded in voltage-clamp. The results suggest that there are two components to the development of the IsAHP, a rapid, voltage- and Ca²⁺-dependent step, the magnitude and rate of which reflects the voltage dependence of the Ca²⁺ channels, that triggers a second rate-limiting, voltage-independent process that dictates the slow IsAHP rise kinetics.     

Pharmacoeconomics: the cost of prophylactic migraine treatments

Migraine preventive medications considered effective reduce headache frequency by 50 percent in approximately 50 percent of treated patients. In spite of similar effectiveness, these medications vary tremendonsly in their prices. Knowledge of medication prices and employing cost-effective strategies may greatly reduce treatment costs.     

Successful management of carotid stenosis in a high-risk population at an inner-city hospital

This is a retrospective review of all carotid endarterectomies (CEA) (n=91) done from 1993 to 2002 at an inner-city hospital (Group I). This group was compared to a randomly selected group of patients (n=445) treated at a private hospital (Group II). The same high-volume surgeons performed CEAs at both hospitals. The majority of Group I patients (71.4%) were members of racial minority groups. They were also more likely to be younger (p<0.001), hypertensive (p<0.03), diabetic (p<0.001), and current smokers (p<0.001); have contralateral carotid artery occlusion (p=0.04); and present with stroke (p<0.001) than Group II patients. Despite this, the incidence of postoperative myocardial infarction (2.2% vs 0.2%, p=0.08), stroke (1.1% vs 1.6%, NS), and death (1.1% vs 0%, NS) was comparable between the 2 groups. Aggressive preoperative workup for occult cardiac disease in Group I revealed an incidence of 25.9% (n=15). Of these, 5 (33.3%) were found to have coronary artery disease severe enough to warrant intervention before CEA. In an inner-city population with increased medical comorbidities, more severe cerebrovascular disease, and relatively low volume of carotid surgery, the results of CEA were comparable to those in patients treated at a high-volume private hospital. The presence of high-volume surgeons, operating at the low-volume municipal hospital, may contribute to the low complication rate. Finally, aggressive preoperative cardiac workup in this underserved population revealed a meaningful incidence of occult coronary artery disease requiring intervention before CEA.     

Design, synthesis, and biological evaluation of thio-containing compounds with serum HDL-cholesterol-elevating properties

A novel series of substituted sulfanyldihydroimidazolones (1) that modulates high-density lipoprotein cholesterol (HDL-C) has been reported to have HDL-elevating properties in several animal models. Concerns about the chemical and metabolic stability of 1 directed us to explore the structure-activity relationship (SAR) of a related series of substituted thiohydantoins (2). Expansion of the scope of the thiohydantoin series led to exploration of compounds in related thio-containing ring systems 3-7 and the N-cyanoguanidine derivative 8. Compounds were tested sequentially in three animal models to assess their HDL-C elevating efficacy and safety profiles. Further evaluation of selected compounds in a dose-response paradigm culminated in the identification of compound 2.39 as a candidate compound for advanced preclinical studies.