Citations

Alveolar epithelial type I cell (ATI) wounding is prevalent in ventilator-injured lungs and likely contributes to pathogenesis of “barotrauma” and “biotrauma.” In experimental models most wounded alveolar cells repair plasma membrane (PM) defects and survive insults. Considering the force balance between edge energy at the PM wound margins and adhesive interactions of the lipid bilayer with the underlying cytoskeleton (CSK), we tested the hypothesis that subcortical actin depolymerization is a key facilitator of PM repair. Using real-time fluorescence imaging of primary rat ATI transfected with a live cell actin-green fluorescent protein construct (Lifeact-GFP) and loaded with N-rhodamine phosphatidylethanolamine (PE), we examined the spatial and temporal coordination between cytoskeletal remodeling and PM repair following micropuncture. Membrane integrity was inferred from the fluorescence intensity profiles of the cytosolic label calcein AM. Wounding led to rapid depolymerization of the actin CSK near the wound site, concurrent with accumulation of endomembrane-derived N-rhodamine PE. Both responses were sustained until PM integrity was reestablished, which typically occurs between ∼10 and 40 s after micropuncture. Only thereafter did the actin CSK near the wound begin to repolymerize, while the rate of endomembrane lipid accumulation decreased. Between 60 and 90 s after successful PM repair, after translocation of the actin nucleation factor cortactin, a dense actin fiber network formed. In cells that did not survive micropuncture injury, actin remodeling did not occur. These novel results highlight the importance of actin remodeling in ATI cell repair and suggest molecular targets for modulating the repair process.

Background— Junctophilin-2 (JPH2), a protein expressed in the junctional membrane complex, is necessary for proper intracellular calcium (Ca 2+ ) signaling in cardiac myocytes. Downregulation of JPH2 expression in a model of cardiac hypertrophy was recently associated with defective coupling between plasmalemmal L-type Ca 2+ channels and sarcoplasmic reticular ryanodine receptors. However, it remains unclear whether JPH2 expression is altered in patients with hypertrophic cardiomyopathy (HCM). In addition, the effects of downregulation of JPH2 expression on intracellular Ca 2+ handling are presently poorly understood. We sought to determine whether loss of JPH2 expression is noted among patients with HCM and whether expression silencing might perturb Ca 2+ handling in a prohypertrophic manner. Methods and Results— JPH2 expression was reduced in flash-frozen human cardiac tissue procured from patients with HCM compared with ostensibly healthy traumatic death victims. Partial silencing of JPH2 expression in HL-1 cells by a small interfering RNA probe targeted to murine JPH2 mRNA (shJPH2) resulted in myocyte hypertrophy and increased expression of known markers of cardiac hypertrophy. Whereas expression levels of major Ca 2+ -handling proteins were unchanged, shJPH2 cells demonstrated depressed maximal Ca 2+ transient amplitudes that were insensitive to L-type Ca 2+ channel activation with JPH2 knockdown. Further, reduced caffeine-triggered sarcoplasmic reticulum store Ca 2+ levels were observed with potentially increased total Ca 2+ stores. Spontaneous Ca 2+ oscillations were elicited at a higher extracellular [Ca 2+ ] and with decreased frequency in JPH2 knockdown cells. Conclusions— Our results show that JPH2 levels are reduced in patients with HCM. Reduced JPH2 expression results in reduced excitation-contraction coupling gain as well as altered Ca 2+ homeostasis, which may be associated with prohypertrophic remodeling.

By the time Harvey Cushing entered medical school, nerve reconstruction techniques had been developed, but peripheral nerve surgery was still in its infancy. As an assistant surgical resident influenced by Dr. William Halsted, Cushing wrote a series of reports on the use of cocaine for nerve blocks. Following his residency training and a hiatus to further his clinical interests and intellectual curiosity, he traveled to Europe and met with a variety of surgeons, physiologists, and scientists, who likely laid the groundwork for Cushing's increased interest in peripheral nerve surgery. Returning to The Johns Hopkins Hospital in 1901, he began documenting these surgeries. Patient records preserved at Yale's Cushing Brain Tumor Registry describe Cushing's repair of ulnar and radial nerves, as well as his exploration of the brachial plexus for nerve repair or reconstruction. The authors reviewed Harvey Cushing's cases and provide 3 case illustrations not previously reported by Cushing involving neurolysis, nerve repair, and neurotization. Additionally, Cushing's experience with facial nerve neurotization is reviewed. The history, physical examination, and operative notes shed light on Cushing's diagnosis, strategy, technique, and hence, his surgery on peripheral nerve injury. These contributions complement others he made to surgery of the peripheral nervous system dealing with nerve pain, entrapment, and tumor.

Introduction: Telemedicine options for symptom assessment include both telephonic means (call centers) and Internet sites. Although symptom assessment call centers have been available for decades, symptom assessment over the Internet is relatively new. It is not well known what types of symptoms Internet users are seeking assessment for and whether extant telephone triage algorithms would be applicable to Internet users. Methods: Symptom assessments on a heavily used Internet site ( MayoClinic.com ) were compared with symptom calls to a U.S. call center (Ask Mayo Clinic). Results: Internet users sought symptom assessments about adult symptoms 13 times more often than children's symptoms. In contrast, over the telephone, adult symptoms were addressed 2.1 times more frequently than children's symptoms. Despite the differences in frequencies of adult and child symptom assessments, users of the Internet and telephone callers asked about specific symptoms with similar relative frequencies. Analysis of 20 adult symptom types shared by the Web and call center revealed that by excluding only 2 assessments (nasal symptoms and leg pain) the remaining 18 showed a significant correlation in counts of use ( r 2 = 0.68, p < 0.001 for linear trend). Conclusions: Internet users have symptoms assessed in similar proportions to callers, with a few exceptions. Compared with callers, Web users are much more likely looking for information about adult symptoms. Callers are proportionally asking more about acute symptoms, whereas Internet users appear more interested in symptom assessment of chronic conditions.

Objectives. Some aspects of the natural history of metachronous colorectal cancer (MCRC), such as the rate of progression from adenomatous polyp to MCRC, are unknown. The objective of this study is to estimate a set of parameters revealing some of these unknown characteristics of MCRC. Methods. The authors developed a computer simulation model that mimics the progression of MCRC for a 5-year period following the treatment of primary colorectal cancer (CRC). They obtained the inputs of the simulation model using longitudinal data for 284 CRC patients from the Mayo Clinic, Rochester. Results. Five-year MCRC incidence and all-cause mortality were 7.4% and 12.7% in the patient cohort, respectively. Statistical analysis showed that 5-year MCRC incidence was associated with gender ( P = 0.05), whereas both all-cause and CRC-related mortalities were associated with age ( P < 0.001 and P = 0.01). Estimated annual probabilities of progression from adenomatous polyp to MCRC and from MCRC to metastatic MCRC were 0.14 and 0.28, respectively. Annual probabilities of mortality after MCRC and metastatic MCRC treatments were estimated to be 0.06 and 0.26, respectively. The estimated annual probability of mortality due to undetected MCRC was 0.16. Conclusions. The results imply that MCRC, especially in women, may be more common than suggested by previous studies. In addition, statistics derived from the clinical data and results of the simulation model indicate that gender and age affect the progression of MCRC.

Abstract Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/advanced colorectal adenomas. Magnification chromoendoscopy (MCE) was performed to identify and characterize rectal aberrant crypt foci (ACF); eligibility criteria required five or more rectal ACFs at baseline. Intervention assignments were as follows: (a) atorvastatin 20 mg qd; (b) sulindac 150 mg bid; (c) oligofructose-enriched inulin (as ORAFTI®Synergy1) 6 gm bid; or (d) control (maltodextrin) 6 gm bid, for 6 months. Percent change in rectal ACF number (%ΔACF) within arm was the primary endpoint. Secondary endpoints included changes in proliferation (Ki67) and apoptosis (caspase-3), as measured from normal mucosa biopsy samples. Among 85 eligible randomized subjects, 76 (86%) completed the trial per protocol. The median (range) of rectal ACF was 9 (5–34) and 8 (0–37) at baseline and postintervention, respectively. The median (SD) for %ΔACF was 5.6 (−69% to 143%), −18.6 (−83% to 160%), −3.6 (−88% to 83%), and −10.0 (−100% to 117%) in the atorvastatin, sulindac, ORAFTI®Synergy1 and control arms, respectively. Neither within-arm (P = 0.12–0.59) nor between-arm (P = 0.30–0.92) comparisons of %ΔACF were statistically significant. The active and control interventions also seemed to have similar effects on mucosal proliferation and apoptosis (P &gt; 0.05 for each comparison). Data from this multicenter, phase II trial do not provide convincing evidence of CRC risk reduction from 6-month interventions with atorvastatin, sulindac, or ORAFTI®Synergy1, although statistical power was limited by the relatively small sample size. Cancer Prev Res; 4(2); 259–69. ©2011 AACR.