Home-field advantage: native gecko exhibits improved exertion capacity and locomotor ability in structurally complex environments relative to its invasive counterpart.

BACKGROUND: Invasive species are of substantial concern because they may threaten ecosystem stability and biodiversity worldwide. Not surprisingly, studies examining the drivers of biological invasion have increased in number over the past few decades in an effort to curtail invasive species success by way of informing management decisions. The common house gecko, Hemidactylus frenatus, has successfully invaded the Pacific islands where it appears to thrive in and dominate non-natural habitats offering high food availability (i.e., well-lit human dwellings) compared to native geckos. Previous work demonstrated that H. frenatus can outperform the native gecko, Lepidodactylus lugubris, in terms of maximal sprint speed on relatively simple planar surfaces (e.g., building walls). Lepidodactylus lugubris and other native geckos, however, may have superior locomotor performance in three-dimensional, structurally complex habitats. RESULTS: Here we compared the locomotor behaviour and exertion capacity of the native gecko, Gehyra oceanica, and the invasive gecko, Hemidactylus frenatus, on the island of Mo'orea, French Polynesia, on fabricated structures simulating structurally complex substrates. We found that the native gecko exhibits improved locomotor performance compared to the invasive gecko on structurally complex substrates. We also completed encounter surveys to document free-ranging habitat use and behaviour of these two species. We discovered that H. frenatus were more common in natural habitats than previously observed and used similar substrates as G. oceanica, although G. oceanica appeared to use substrates with greater perch heights (i.e., trees). CONCLUSIONS: Our findings revealed that locomotor performance in complex environments may contribute to the previously observed habitat segregation between native and invasive Pacific island geckos. Furthermore, our locomotor and habitat use data are consistent with the hypothesis that G. oceanica may be resistant to invasion of H. frenatus in natural environments. Our study calls for more detailed ecophysiological and ecomorphological studies of both native and invasive Pacific gecko species.

A multimodal 3D imaging approach of pore networks in the human femur to assess age-associated vascular expansion and Lacuno-Canalicular reduction.

Cellular communication in the mechanosensory osteocyte Lacuno-Canalicular Network (LCN) regulates bone tissue remodeling throughout life. Age-associated declines in LCN size and connectivity dysregulate mechanosensitivity to localized remodeling needs of aging or damaged tissue, compromising bone quality. Synchrotron radiation-based micro-Computed Tomography (SRµCT) and Confocal Laser Scanning Microscopy (CLSM) were employed to visualize LCN and vascular canal morphometry in an age series of the anterior femur (males n = 14, females n = 11, age range = 19-101, mean age = 55). Age-associated increases in vascular porosity were driven by pore coalescence, including a significant expansion in pore diameter and a significant decline in pore density. In contrast, the LCN showed significant age-associated reductions in lacunar volume fraction, mean diameter, and density, and in canalicular volume fraction and connectivity density. Lacunar density was significantly lower in females across the lifespan, exacerbating their age-associated decline. Canalicular connectivity density was also significantly lower in females but approached comparable declining male values in older age. Our data illuminate the trajectory and potential morphometric sources of age-associated bone loss. Increased vascular porosity contributes to bone fragility with aging, while an increasingly reduced and disconnected LCN undermines the mechanosensitivity required to repair and reinforce bone. Understanding why and how this degradation occurs is essential for improving the diagnosis and treatment of age-related changes in bone quality and fragility.

Contemporary management of tricuspid regurgitation: an updated clinical review.

Tricuspid regurgitation (TR) is a complex and insidious valvular pathology that represents a complex decision and management algorithm for patients. TR is present in a significant proportion of the population and is especially prevalent in patients with advanced heart failure. Patients with TR have been demonstrated to have a decreased survival even with normal left heart function. TR can be a result of pathology that directly affects the valvular structure (i.e., Ebstein anomaly) or as a result of increased forward pressures (ie, pulmonary hypertension, left heart failure). Conservative management of patients with TR is primarily symptomatic relief. Definitive therapy involves surgical repair of the tricuspid valve. Furthermore, as more patients develop advanced heart failure, the management of TR in patients with left ventricular assist devices has become necessary because of the evidence of increased in-hospital morbidity and a trend toward decreased survival.

Human immunodeficiency virus infection as a prognostic factor in surgical patients with non-small cell lung cancer.

BACKGROUND: The purpose of this study was to assess the effect of human immunodeficiency virus (HIV) infection on postoperative survival among non-small cell lung cancer (NSCLC) patients. METHODS: A retrospective cohort study compared 22 HIV-infected lung cancer patients to 2,430 lung cancer patients with HIV-unspecified status who underwent resection at Johns Hopkins Hospital from 1985 to 2009. Subcohort comparative analyses were performed using individual matching methods. RESULTS: Thirty-day mortality rates did not differ between HIV-infected and HIV-unspecified patients. Survival rates for HIV-infected lung cancer patients were significantly shorter than for HIV-unspecified patients (median, 26 versus 48 months; p=0.001). After adjustment, the relative hazard of mortality among HIV-infected NSCLC patients was more than threefold that of HIV-unspecified patients (adjusted hazard ratio, 3.08; 95% confidence interval: 1.85 to 5.13). When additional surgical characteristics were modeled in a matched subcohort, the association remained statistically significant (adjusted hazard ratio, 2.31; 95% confidence interval: 1.11 to 4.81). Moreover, HIV-infected lung cancer patients with CD4 counts less than 200 cells/mm3 had shortened median survival compared with patients whose CD4 counts were 200 cells/mm3 or greater (8 versus 40 months; p=0.031). Postoperative pulmonary and infectious complications were also elevated in the HIV-infected group (p=0.001 and p<0.001, respectively). After surgery, median time to cancer progression was shorter among HIV-infected patients (20.4 months) versus HIV-unspecified patients (p=0.061). CONCLUSIONS: The HIV-infected NSCLC patients have more postoperative complications, rapid progression to disease recurrence, and poorer postoperative survival. Optimizing immune status before surgery and careful patient selection based on diffusion capacity of lung for carbon monoxide may improve patient outcomes.

Recurrence after neoadjuvant chemoradiation and surgery for esophageal cancer: does the pattern of recurrence differ for patients with complete response and those with partial or no response?

OBJECTIVE: We hypothesized that most relapses in patients with esophageal cancer having neoadjuvant chemoradiation therapy would occur outside of the surgical and radiation fields. METHODS: Recurrence patterns, time to recurrence, and median survival were examined in 267 patients who had esophagectomy after neoadjuvant chemoradiation therapy at Johns Hopkins over 19 years. RESULTS: Of 267 patients, 82 (30.7%) showed complete response to neoadjuvant therapy, with 108 (40.4%) and 77 (28.8%) showing partial response or no response, respectively. Recurrence developed in 84 patients (patients with complete response 18/82, 21.4%; patients with partial response 39/108, 36.1%; patients with no response 27/77, 35.1%; P = .055, respectively). Most patients had recurrences at distant sites (65/84;77.4%) regardless of pathologic response, and subsequent survival was brief (median 8.37 months). Median disease-free survival was short (10 months) and did not differ based on recurrence site for patients with partial response or no response, but was longer for patients with complete response with distant recurrence, whose median disease-free survival was 27.3 months (P = .008). By multivariate analysis, no other factor except for pathologic response to neoadjuvant therapy was associated with disease recurrence or death. Patients with partial response or no response were 1.97 and 2.23 times more likely to have recurrence than patients with complete response (P = .024 and P = .012, respectively). CONCLUSIONS: Most esophageal cancer recurrences after neoadjuvant therapy and surgery are distant, and survival time after recurrence is short regardless of pathologic response. Fewer patients achieving complete response had recurrences, and distant recurrences in these patients manifest later than in patients showing partial response and those showing no response. Only pathologic response is significantly associated with disease recurrence, suggesting that tumor biology and chemosensitivity are critical in long-term patient outcome.