Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions.

INTRODUCTION: It is common for men to develop erectile dysfunction after radical prostatectomy. The anatomy of the rat allows the cavernous nerve (CN) to be identified, dissected, and injured in a controlled fashion. Therefore, bilateral CN injury (BCNI) in the rat model is routinely used to study post-prostatectomy erectile dysfunction. AIM: To compare and contrast the available literature on pharmacologic intervention after BCNI in the rat. METHODS: A literature search was performed on PubMed for cavernous nerve and injury and erectile dysfunction and rat. Only articles with BCNI and pharmacologic intervention that could be grouped into categories of immune modulation, growth factor therapy, receptor kinase inhibition, phosphodiesterase type 5 inhibition, and anti-inflammatory and antifibrotic interventions were included. MAIN OUTCOME MEASURES: To assess outcomes of pharmaceutical intervention on erectile function recovery after BCNI in the rat model. The ratio of maximum intracavernous pressure to mean arterial pressure was the main outcome measure chosen for this analysis. RESULTS: All interventions improved erectile function recovery after BCNI based on the ratio of maximum intracavernous pressure to mean arterial pressure results. Additional end-point analysis examined the corpus cavernosa and/or the major pelvic ganglion and CN. There was extreme heterogeneity within the literature, making accurate comparisons between crush injury and therapeutic interventions difficult. CONCLUSIONS: BCNI in the rat is the accepted animal model used to study nerve-sparing post-prostatectomy erectile dysfunction. However, an important limitation is extreme variability. Efforts should be made to decrease this variability and increase the translational utility toward clinical trials in humans. Haney NM, Nguyen HMT, Honda M, et al. Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions. Sex Med Rev 2018;6:234-241.

Size-dependent mechanical properties of axial and radial mixed AlN/GaN nanostructure.

In this paper, continuum multiscale models are proposed to describe the size-dependent mechanical properties of two kinds of heterogeneous nanostructures: radially heterogeneous nanowires and longitudinally heterogeneous nanolaminates. In both cases, the continuum models involve additional surface/interface energies, which allow capturing size effects. Several models of imperfect interface models, like coherent and spring-layer ones, are shown to respectively capture the size effects, which are reported by first-principles calculations performed on heterogeneous nanostructures. In each case, a procedure is proposed to identify the parameters of the surface/interface model in the continuum framework, based on first-principles calculations performed on slab systems. The obtained continuum models allow avoiding full computations on atomistic models, which are not affordable for large sizes (diameters, layer thickness). An increase of the overall stiffness for both kinds of heterogeneous AlN/GaN nanostructures with the decrease of the dimensions is evidenced. The continuum models are then compared with full first-principles calculations to demonstrate their accuracy and their ability to capture size effects.

The rising incidence of melanoma in children and adolescents.

Although melanoma is a rare occurrence in childhood and adolescence, recent reports indicate a rise in its incidence. This concerning trend is largely attributed to increasing amounts of sun exposure. Health care providers can intervene by the early identification and treatment of melanomas and educating children about sun-protective behaviors.

Rare cutaneous malignancies of childhood.

Malignant melanoma and mycosis fungoides (cutaneous T cell lymphoma) are rare malignancies in childhood. However, both are potentially fatal tumors that may be cured if detected early. The incidence of melanomas in adolescents has increased in the last 10 years. This makes it imperative that high-risk children be identified for preventive measures including sun protection as well as serial skin examinations. This review highlights the important risk factors for melanoma and comments on which risk-reducing interventions pediatricians should institute. Mycosis fungoides is a cutaneous malignancy usually found in middle-aged adults. Recently, it has been asserted that this entity is underreported in children. This occurs because it may frequently mimic other more common disorders, such as eczema. Thus, lesions clinically suspicious for mycosis fungoides, especially those that have failed chronic eczema therapies, warrant a skin biopsy for definitive diagnosis.

Prediction of outcome in intensive care unit trauma patients: a multicenter study of Acute Physiology and Chronic Health Evaluation (APACHE), Trauma and Injury Severity Score (TRISS), and a 24-hour intensive care unit (ICU) point system.

OBJECTIVE: To conduct a multicenter study to validate the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) II system, APACHE III system, Trauma and Injury Severity Score (TRISS) methodology, and a 24-hour intensive care unit (ICU) point system for prediction of mortality in ICU trauma patient admissions. METHODS: The study population consisted of retrospectively identified, consecutive ICU trauma admissions (n = 2,414) from six Level I trauma centers. Probabilities of death were calculated by using logistic regression analysis. The predictive power of each system was evaluated by using decision matrix analysis to compare observed and predicted outcomes with a decision criterion of 0.50 for risk of hospital death. The Youden Index (YI) was used to compare the proportion of patients correctly classified by each system. Measures of model calibration were based on goodness-of-fit testing (Hosmer-Lemeshow statistic less than 15.5) and model discrimination were based on the area under the receiver operating characteristic curve (AUC). RESULTS: Overall, APACHE II (sensitivity, 38%; specificity, 99%; YI, 37%; H-L statistic, 92.6; AUC, 0.87) and TRISS (sensitivity, 52%; specificity, 94%; YI, 46%; H-L statistic, 228.1; AUC, 0.82) were poor predictors of aggregate mortality, because they did not meet the acceptable thresholds for both model calibration and discrimination. APACHE III (sensitivity, 60%; specificity, 98%; YI, 58%; H-L statistic, 7.0; AUC, 0.89) was comparable to the 24-hour ICU point system (sensitivity, 51%; specificity, 98%; YI, 50%; H-L statistic, 14.7; AUC, 0.89) with both systems showing strong agreement between the observed and predicted outcomes based on acceptable thresholds for both model calibration and discrimination. The APACHE III system significantly improved upon APACHE II for estimating risk of death in ICU trauma patients (p < 0.001). Compared with the overall performance, for the subset of patients with nonoperative head trauma, the percentage correctly classified was decreased to 46% for APACHE II; increased to 71% for APACHE III (p < 0.001 vs. APACHE II); increased to 59% for TRISS; and increased to 62% for 24-hour ICU points. For operative head trauma, the percentage correctly classified was increased to 60% for APACHE II; increased to 61% for APACHE III; decreased to 43% for TRISS (p < 0.004 vs. APACHE III); and increased to 54% for 24-hour ICU points. For patients without head injuries, all of the systems were unreliable and considerably underestimated the risk of death. The percentage of nonoperative and operative patients without head trauma who were correctly classified was decreased, respectively, to 26% and 30% for APACHE II; 33% and 29% for APACHE III; 33% and 19% for TRISS; 20% and 23% for 24-hour ICU points. CONCLUSION: For the overall estimation of aggregate ICU mortality, the APACHE III system was the most reliable; however, performance was most accurate for subsets of patients with head trauma. The 24-hour ICU point system also demonstrated acceptable overall performance with improved performance for patients with head trauma. Overall, APACHE II and TRISS did not meet acceptable thresholds of performance. When estimating ICU mortality for subsets of patients without head trauma, none of these systems had an acceptable level of performance. Further multicenter studies aimed at developing better outcome prediction models for patients without head injuries are warranted, which would allow trauma care providers to set uniform standards for judging institutional performance.

Occupational exposure and chronic respiratory symptoms--a population based study in Vietnam.

In order to investigate the relationship between occupational exposure to dust/chemicals (toxic gases/fumes) and chronic respiratory symptoms in Vietnam, the questionnaire standardized by the American Thoracic Society was applied to 368 subjects living in Ha Thai district of Vietnam. According to the results of multiple logistic regression analyses, the odds ratios of chronic respiratory symptoms by occupational exposure are over unity, except for the relationship between chronic cough and occupational exposure to chemicals. Especially for chronic breathlessness, significantly higher odds ratios are observed among people with a history of occupational exposure to dust or chemicals: 2.925 (95% CI: 1.130-7.574) for dust, and 3.721 (95% CI: 1.412-9.803) for chemicals. As for the interaction between occupational exposure to dust and cigarette smoking, it is considered that occupational exposure leads to an increase in chronic respiratory symptoms independent of the effects of cigarette smoking.

Influence of age, dietary protein and weaning on calf abomasal enzymic secretion.

Using fistulated calves, the influence of the age, type of dietary protein and weaning on the secretion of chymosin and pepsin by the abomasum were studied. The abomasum secreted both chymosin and pepsin when the animals were fed milk. Chymosin secretion appeared to be independent of the age of the animals whereas a slow increase in pepsin secretion was observed as the calves aged. Several preruminant animals were fed either a skim-milk diet or a milk substitute in which proteins were provided by fish, soya or whey concentrates. Each of these 3 milk substitutes led to a decrease in chymosin secretion without modification of pepsin secretion. Chymosin secretion was partly restored when the claves were again given a skim-milk diet. At weaning, chymosin secretion dropped abruptly, but the pepsin level was not affected. These results indicate that milk (most probably its casein fraction) is responsible for the activation of chymosin secretion.