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ABSTRACT OBJECTIVE To determine the clinical presentation, imaging characteristics, microscopic and ultrastructural characteristics, and treatment outcomes of patients with clinically silent pituitary corticotroph adenomas. METHODS All silent corticotroph adenomas diagnosed at the Mayo Clinic during the years 1975 through 1997 were selected from the files of the Mayo Tissue Registry. RESULTS We studied 23 cases, occurring in 16 male and 7 female patients (age range, 11–79 yr; mean age, 48 yr), who presented with headaches (50%), visual field defects (61%), extraocular muscle paresis (13%), hypopituitarism (26%), and galactorrhea/amenorrhea (43%/29% of the female patients). No patients exhibited clinical hypercortisolism. All tumors were macroadenomas (2.4 ± 0.8 cm; range, 1.5–4.0 cm) and exhibited suprasellar extension in 87% of the cases and hemorrhage, necrosis, and/or cystic changes in 61%. All tumors stained were variably periodic acid-Schiff-, adrenocorticotropic hormone-, and β-endorphin-positive, particularly Subtype I lesions. Ultrastructural classification was performed in 19 cases. In a comparison of Subtype I and II tumors, differences were observed with respect to sex (male/female, 1.4:1 versus 6:1), preoperative hyperprolactinemia (5 of 16 versus 0 of 6 cases), preoperative hypopituitarism (9 of 16 versus 5 of 7 cases), radiographic or gross invasion (7 of 16 versus 5 of 7 cases), and partial or total postoperative pituitary failure (6 of 16 versus 6 of 6 cases). The overall median postoperative follow-up period was 4.9 years (range, 0.3–16.6 yr); 54% of the patients had persistent or recurrent tumors. CONCLUSION Clinically silent corticotroph adenomas behave in an aggressive manner and are characterized by the following: lack of clinical signs or symptoms of Cushing's syndrome and normal cortisol levels; no or only minor elevations of serum adrenocorticotropic hormone levels; macroadenomas with hemorrhagic infarction; and presentation dominated by mass effect symptoms. The high persistence/recurrence rate underscores the need for long-term follow-up.

Objective.To determine why people do or do not wear helmets while bicycling.Methods.A survey was conducted from August through October 1999. Two survey areas were chosen for this study: local public schools and paved bicycle trails. For the school arm of the study, 3 public elementary, middle, and high schools were selected from 3 different regions of Rochester, Minnesota, for participation in the study. For the bicycle arm of the study, 3 paved trails located in southeastern Minnesota were selected. A total of 2970 surveys were distributed to the public school system, and 463 surveys were collected from bicyclists on the paved bicycle trails. The survey population was split into 3 age categories for analysis: child (7–10), adolescent (11–19), and adult (older than 19).Results.Of the 2970 surveys distributed to Rochester public schools, 2039 (69%) were returned for analysis. Seventy-eight of the surveys that were completed in the public school system were discarded for the following reasons: age <10 years (35), insufficient completion (24), and selection of every reason for not wearing a bicycle helmet (19). A total of 463 surveys were completed on the 3 paved bicycle trails. One survey from the paved bicycle trail arm of the study was discarded because of insufficient completion. The total number of surveys used for statistical analysis was 2424. The distribution of male (52.7%) and female (47.3%) participants was similar. No significant difference in bicycle helmet use was found between genders.The age groups with the highest rate of bicycle helmet use were 50 to 59 years (62%) and older than 59 years (70%). The age groups with the lowest rate of bicycle helmet use were 11 to 19 years (31%) and 30 to 39 years (30%). The most common reasons given for not wearing a bicycle helmet were “uncomfortable,” “annoying,” “it's hot,” “don't need it,” and “don't own one.” Bicycle helmet use was significantly influenced by peer helmet use in all 3 age groups. Children also were more likely to wear a bicycle helmet when their parents wore bicycle helmets.A majority of respondents in all 3 age groups indicated that bicycle helmets provided either “moderate” or “great” protection from head injury, although significantly more adults (65.9%) than adolescents (43.9%) believed that the protection afforded by bicycle helmets was “great.” Despite this belief, a majority of adolescents and adults indicated that there was only a “slight risk” of head injury when bicycling without a helmet. Participants in all 3 categories were more likely to wear a bicycle helmet when they indicated either that there was a “great risk” of head injury when bicycling without a helmet or that helmets provided “great protection” from head injury. Adolescents and adults who believed that bicycling without a helmet put one at “great risk” for head injury also were more likely to indicate that helmets provided “great protection” from head injury.Conclusions.The prevalence of bicycle helmet use remains low despite research indicating the high level of head injury risk when bicycling without a helmet and the significant protection afforded by bicycle helmets. With the information provided by this survey, a well-designed intervention to increase the use of bicycle helmets can be implemented. Suggestions for a campaign to promote an increase in bicycle helmet use include focusing efforts on males and females between 11 and 19 years and 30 and 39 years of age; educating the public on new bicycle helmet designs that address comfort, ventilation, and fashion; educating adolescents on the significant protection from head injury afforded by bicycle helmets; and educating the public on the risk and severity of head injury associated with bicycling without a helmet. The influence of parents and peers on bicycle helmet use may be targeted through education and statements such as, “If you wear a bicycle helmet, you are not only protecting yourself, you are also helping to protect your friends and/or children.” bicycle, helmet, injury, accident, prevention.

Background— Revascularization strategies often hinge on the presence and degree of left anterior descending coronary artery (LAD) stenosis. A decision for bypass surgery is often based on the durability of surgical LAD revascularization compared with percutaneous approaches. By decreasing restenosis, drug-eluting stents may have reduced the “reintervention gap” between surgery and percutaneous intervention, making the percutaneous route preferable. Methods and Results— Of the 1101 patients in the SIRIUS trial, 459 with an LAD stenosis were randomized to percutaneous intervention with either sirolimus-eluting or bare-metal stents. Baseline demographic, clinical, and angiographic data were obtained. Patients had 1-year clinical and 8-month angiographic follow-up. Baseline characteristics were similar in both groups. The majority of lesions were tubular type B lesions (69.7%) with a mean diameter of 2.73 mm and a mean length of 14.0 mm. The binary in-stent restenosis rate was 2% for the sirolimus stent group and 41.6% for the bare-metal arm (relative risk, 0.05; 95% CI, 0.02 to 0.1; P <0.001). One-year major adverse events (defined as cardiac death, Q-wave and non–Q-wave myocardial infarction, or target vessel revascularization) was decreased 59% in the sirolimus-stent group (9.8% versus 24.9%; relative risk, 0.39; 95% CI, 0.26 to 0.61; P <0.001). Subgroup analysis of 135 patients with proximal LAD lesions showed similar benefits. In-stent restenosis was 0 in the proximal LAD sirolimus-eluting group (n=67), compared with 38% in the bare-metal arm (n=68), and major adverse events demonstrated a similar trend, with a 50% decrease compared with control patients (10.4% versus 20.6%, P =NS). Conclusions— Sirolimus-eluting stents significantly decrease revascularization rates in LAD lesions. At 1 year, sirolimus-eluting stent revascularization rates are comparable to historic single vessel bypass surgery revascularization rates.

Proteins in the transforming growth factor-β (TGF-β) family recognize transmembrane serine/threonine kinases known as type I and type II receptors. Binding of TGF-β to receptors results in receptor down-regulation and signaling. Whereas previous work has focused on activities controlling TGF-β signaling, more recent studies have begun to address the trafficking properties of TGF-β receptors. In this report, it is shown that receptors undergo recycling both in the presence and absence of ligand activation, with the rates of internalization and recycling being unaffected by ligand binding. Recycling occurs as receptors are most likely internalized through clathrin-coated pits, and then returned to the plasma membrane via a rab11-dependent, rab4-independent mechanism. Together, the results suggest a mechanism wherein activated TGF-β receptors are directed to a distinct endocytic pathway for down-regulation and clathrin-dependent degradation after one or more rounds of recycling.

Background— Clinical and radiologic predictors of cerebral infarction occurrence and location after aneurysmal subarachnoid hemorrhage have been seldom studied. Methods— We evaluated all patients admitted to our hospital with aneurysmal subarachnoid hemorrhage between 1998 and 2000. Cerebral infarction was defined as a new hypodensity located in a vascular distribution on computed tomography (CT) scan. Results— Fifty-seven of 143 patients (40%) developed a cerebral infarction. On univariate analysis, occurrence of cerebral infarction was associated with a worse World Federation of Neurological Surgeons grade ( P =0.01), use of ventriculostomy catheter ( P =0.01), preoperative vasospasm ( P =0.03), surgical clipping ( P =0.02), symptomatic vasospasm ( P <0.01), and vasospasm on transcranial Doppler ultrasonography (TCD) or repeat angiogram ( P <0.01). On multivariable analysis, only presence of symptoms ascribed to vasospasm ( P <0.01) and evidence of vasospasm on TCD or angiogram predicted cerebral infarction ( P <0.01). TCD and angiogram agreed on the diagnosis of vasospasm in 73% of cases (95% CI, 63% to 81%), but the diagnostic accuracy of this combination of tests was suboptimal for the prediction of cerebral infarction occurrence (sensitivity, 0.72; specificity, 0.68; positive predictive value, 0.67; negative predictive value, 0.72). Location of the cerebral infarction on delayed CT was predicted by neurological symptoms in 74%, by aneurysm location in 77%, and by angiographic vasospasm in 67%. Conclusions— Evidence of vasospasm on TCD and angiogram is predictive of cerebral infarction on CT scan but sensitivity and specificity are suboptimal. Cerebral infarction location cannot be predicted in one quarter to one third of patients by any of the studied clinical or radiological variables.