3D Imaging and Mechanical Modeling of Helical Buckling in Medicago truncatula Plant Roots

We study the primary root growth of wild-type Medicago truncatula plants in heterogeneous environments using 3D time-lapse imaging. The growth medium is a transparent hydrogel consisting of a stiff lower layer and a compliant upper layer. We find that the roots deform into a helical shape just above the gel layer interface before penetrating into the lower layer. This geometry is interpreted as a combination of growth-induced mechanical buckling modulated by the growth medium and a simultaneous twisting near the root tip. We study the helical morphology as the modulus of the upper gel layer is varied and demonstrate that the size of the deformation varies with gel stiffness as expected by a mathematical model based on the theory of buckled rods. Moreover, we show that plant-to-plant variations can be accounted for by biomechanically plausible values of the model parameters

3D Imaging and Mechanical Modeling of Helical Buckling in Medicago truncatula Plant Roots

We study the primary root growth of wild-type Medicago truncatula plants in heterogeneous environments using 3D time-lapse imaging. The growth medium is a transparent hydrogel consisting of a stiff lower layer and a compliant upper layer. We find that the roots deform into a helical shape just above the gel layer interface before penetrating into the lower layer. This geometry is interpreted as a combination of growth-induced mechanical buckling modulated by the growth medium and a simultaneous twisting near the root tip. We study the helical morphology as the modulus of the upper gel layer is varied and demonstrate that the size of the deformation varies with gel stiffness as expected by a mathematical model based on the theory of buckled rods. Moreover, we show that plant-to-plant variations can be accounted for by biomechanically plausible values of the model parameters

Rest and treatment/rehabilitation following sport-related concussion: a systematic review

AIM OR OBJECTIVE: The objective of this systematic review was to evaluate the evidence regarding rest and active treatment/rehabilitation following sport-related concussion (SRC). DESIGN: Systematic review. DATA SOURCES: MEDLINE (OVID), CINAHL (EbscoHost), PsycInfo (OVID), Cochrane Central Register of Controlled Trials (OVID), SPORTDiscus (EbscoHost), EMBASE (OVID) and Proquest DissertationsandTheses Global (Proquest) were searched systematically. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were included if they met the following criteria: (1) original research; (2) reported SRC as the diagnosis; and (3) evaluated the effect of rest or active treatment/rehabilitation. Review articles were excluded. RESULTS: Twenty-eight studies met the inclusion criteria (9 regarding the effects of rest and 19 evaluating active treatment). The methodological quality of the literature was limited; only five randomised controlled trials (RCTs) met the eligibility criteria. Those RCTs included rest, cervical and vestibular rehabilitation, subsymptom threshold aerobic exercise and multifaceted collaborative care. SUMMARY/CONCLUSIONS: A brief period (24-48 hours) of cognitive and physical rest is appropriate for most patients. Following this, patients should be encouraged to gradually increase activity. The exact amount and duration of rest are not yet well defined and require further investigation. The data support interventions including cervical and vestibular rehabilitation and multifaceted collaborative care. Closely monitored subsymptom threshold, submaximal exercise may be of benefit. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2016:CRD42016039570

Smoking Enhances Risk for New External Genital Warts in Men

Repeat episodes of HPV-related external genital warts reflect recurring or new infections. No study before has been sufficiently powered to delineate how tobacco use, prior history of EGWs and HIV infection affect the risk for new EGWs. Behavioral, laboratory and examination data for 2,835 Multicenter AIDS Cohort Study participants examined at 21,519 semi-annual visits were evaluated. Fourteen percent (391/2835) of men reported or were diagnosed with EGWs at 3% (675/21,519) of study visits. Multivariate analyses showed smoking, prior episodes of EGWs, HIV infection and CD4+ T-lymphocyte count among the infected, each differentially influenced the risk for new EGWs

Life-Expectancy Disparities Among Adults With HIV in the United States and Canada: The Impact of a Reduction in Drug- and Alcohol-Related Deaths Using the Lives Saved Simulation Model.

Improvements in life expectancy among people living with human immunodeficiency virus (PLWH) receiving antiretroviral treatment in the United States and Canada might differ among key populations. Given the difference in substance use among key populations and the current opioid epidemic, drug- and alcohol-related deaths might be contributing to the disparities in life expectancy. We sought to estimate life expectancy at age 20 years in key populations (and their comparison groups) in 3 time periods (2004-2007, 2008-2011, and 2012-2015) and the potential increase in expected life expectancy with a simulated 20% reduction in drug- and alcohol-related deaths using the novel Lives Saved Simulation model. Among 92,289 PLWH, life expectancy increased in all key populations and comparison groups from 2004-2007 to 2012-2015. Disparities in survival of approximately a decade persisted among black versus white men who have sex with men and people with (vs. without) a history of injection drug use. A 20% reduction in drug- and alcohol-related mortality would have the greatest life-expectancy benefit for black men who have sex with men, white women, and people with a history of injection drug use. Our findings suggest that preventing drug- and alcohol-related deaths among PLWH could narrow disparities in life expectancy among some key populations, but other causes of death must be addressed to further narrow the disparities

Oral leukoplakia and risk of progression to oral cancer: A population-based cohort study

BACKGROUND: The optimal clinical management of oral precancer remains uncertain. We investigated the natural history of oral leukoplakia, the most common oral precancerous lesion, to estimate the relative and absolute risks of progression to cancer, the predictive accuracy of a clinician\u27s decision to biopsy a leukoplakia vis-à-vis progression, and histopathologic predictors of progression. METHODS: We conducted a retrospective cohort study (1996-2012) of patients with oral leukoplakia (n = 4886), identified using electronic medical records within Kaiser Permanente Northern California. Among patients with leukoplakia who received a biopsy (n = 1888), we conducted a case-cohort study to investigate histopathologic predictors of progression. Analyses included indirect standardization and unweighted or weighted Cox regression. RESULTS: Compared with the overall Kaiser Permanente Northern California population, oral cancer incidence was substantially elevated in oral leukoplakia patients (standardized incidence ratio = 40.8, 95% confidence interval [CI] = 34.8 to 47.6; n = 161 cancers over 22 582 person-years). Biopsied leukoplakias had a higher oral cancer risk compared with those that were not biopsied (adjusted hazard ratio = 2.38, 95% CI = 1.73 to 3.28). However, to identify a prevalent or incident oral cancer, the biopsy decision had low sensitivity (59.6%), low specificity (62.1%), and moderate positive-predictive value (5.1%). Risk of progression to oral cancer statistically significantly increased with the grade of dysplasia; 5-year competing risk-adjusted absolute risks were: leukoplakia overall = 3.3%, 95% CI = 2.7% to 3.9%; no dysplasia = 2.2%, 95% CI = 1.5% to 3.1%; mild-dysplasia = 11.9%, 95% CI = 7.1% to 18.1%; moderate-dysplasia = 8.7%, 95% CI = 3.2% to 17.9%; and severe dysplasia = 32.2%, 95% CI = 8.1%-60.0%. Yet 39.6% of cancers arose from biopsied leukoplakias without dysplasia. CONCLUSIONS: The modest accuracy of the decision to biopsy a leukoplakia vis-à-vis presence or eventual development of oral cancer highlights the need for routine biopsy of all leukoplakias regardless of visual or clinical impression. Leukoplakia patients, particularly those with dysplasia, need to be closely monitored for signs of early cancer

HMG-CoA reductase inhibitors (statins) use and risk of non-Hodgkin lymphoma in HIV-positive persons

Objective: Experimental studies suggested that HMG-CoA reductase inhibitors ('statins') may have antilymphoma properties. We investigated whether statin use is associated with reduced risk of non-Hodgkin lymphoma (NHL) in HIV-positive persons. Design: A nested case-control study was conducted among HIV-positive members of Kaiser Permanente California, a large managed care organization. Methods: Cases were incident HIVþ NHL diagnosed from 1996 to 2008. Controls were HIV-positive members without NHL matched 5 : 1 to cases by age, sex, race, index year and known duration of HIV infection. Data were collected from Kaiser Permanente's electronic medical records. Conditional logistic regression was used to examine the effect of statin use on HIV þ NHL risk, adjusting for potential confounders (matching factors, prior clinical AIDS diagnosis, antiretroviral use, baseline CD4 cell count, and history of selected co-morbidity) and use of nonstatin lipid-lowering therapy (LLT). Results: A total of 259 cases and 1295 controls were included. Eight percent of the cases and 14% of the controls had a history of statin use. Statin use was associated with lower risk of HIV þ NHL; hazard ratio and 95% confidence intervals for ever use, less than 12, and at least 12 months cumulative use was 0.55 (0.31-0.95), 0.64 (0.31-1.28), and 0.50 (0.23-1.10), respectively. P value for trend for duration of statin use was 0.08. No association between nonstatin LLT use and risk of NHL was observed

Temporal pattern of C1q deposition after transient focal cerebral ischemia

Recent studies have focused on elucidating the contribution of individual complement proteins to post-ischemic cellular injury. As the timing of complement activation and deposition after cerebral ischemia is not well understood, our study investigates the temporal pattern of C1q accumulation after experimental murine stroke. Brains were harvested from mice subjected to transient focal cerebral ischemia at 3, 6, 12, and 24 hr post reperfusion. Western blotting and light microscopy were employed to determine the temporal course of C1q protein accumulation and correlate this sequence with infarct evolution observed with TTC staining. Confocal microscopy was utilized to further characterize the cellular localization and characteristics of C1q deposition. Western Blot analysis showed that C1q protein begins to accumulate in the ischemic hemisphere between 3 and 6 hr post-ischemia. Light microscopy confirmed these findings, showing concurrent C1q protein staining of neurons. Confocal microscopy demonstrated co-localization of C1q protein with neuronal cell bodies as well as necrotic cellular debris. These experiments demonstrate the accumulation of C1q protein on neurons during the period of greatest infarct evolution. This data provides information regarding the optimal time window during which a potentially neuroprotective anti-C1q strategy is most likely to achieve therapeutic success. © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50651/1/20775_ftp.pd

Management of aneurysms involving branches of the celiac and superior mesenteric arteries: A comparison of surgical and endovascular therapy

ObjectiveAneurysms involving branches of the superior mesenteric and celiac arteries are uncommon and require proper management to prevent rupture and death. This study compares surgical and endovascular treatment of these aneurysms and analyzes outcome.MethodsPatients at the Mount Sinai Medical Center in New York who were treated for aneurysms in the branches of the celiac artery and superior mesenteric artery were identified through a search of the institution’s medical records and endovascular database. Patient demographics, history, clinical presentation, aneurysm characteristics, treatments, and follow-up outcome were retrospectively recorded. Significant differences between patients treated by surgical or endovascular therapy were determined by using Student’s t test and χ 2 analysis.ResultsBetween January 1, 1991, and July 1, 2005, 59 patients with 61 aneurysms were treated at a single institution. Twenty-four patients had surgical repair, and 35 underwent endovascular treatment, which included coil embolization and stent-graft therapy. Splenic (28) and hepatic (22) artery aneurysms predominated. Eighty-nine percent of splenic artery aneurysms were true aneurysms and were treated by endovascular and surgical procedures in near equal numbers (14 and 11, respectively). Pseudoaneurysms were significantly more likely to be treated by endovascular means (P < .01). The technical success rate of endovascular treatment for aneurysms was 89%, and failures were successfully treated by repeat coil embolization in all patients who presented for retreatment. Patients treated by endovascular techniques had a significantly higher incidence of malignancy than patients treated with open surgical techniques (P = .03). Furthermore, patients treated by endovascular means had a shorter in-hospital length of stay (2.4 vs 6.6 days, P < .001).ConclusionEndovascular management of visceral aneurysms is an effective means of treating aneurysms involving branches of the celiac and superior mesenteric arteries and is particularly useful in patients with comorbidities, including cancer. It is associated with a decreased length of stay in the elective setting, and failure of primary treatment can often be successfully managed percutaneously

Weight gain among treatment-naïve persons with HIV starting integrase inhibitors compared to non-nucleoside reverse transcriptase inhibitors or protease inhibitors in a large observational cohort in the United States and Canada.

IntroductionWeight gain following antiretroviral therapy (ART) initiation is common, potentially predisposing some persons with HIV (PWH) to cardio-metabolic disease. We assessed relationships between ART drug class and weight change among treatment-naïve PWH initiating ART in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD).MethodsAdult, treatment-naïve PWH in NA-ACCORD initiating integrase strand transfer inhibitor (INSTI), protease inhibitor (PI) or non-nucleoside reverse-transcriptase inhibitor (NNRTI)-based ART on/after 1 January 2007 were followed through 31 December 2016. Multivariate linear mixed effects models estimated weight up to five years after ART initiation, adjusting for age, sex, race, cohort site, HIV acquisition mode, treatment year, and baseline weight, plasma HIV-1 RNA level and CD4+ cell count. Due to shorter follow-up for PWH receiving newer INSTI drugs, weights for specific INSTIs were estimated at two years. Secondary analyses using logistic regression and all covariates from primary analyses assessed factors associated with &gt;10% weight gain at two and five years.ResultsAmong 22,972 participants, 87% were male, and 41% were white. 49% started NNRTI-, 31% started PI- and 20% started INSTI-based regimens (1624 raltegravir (RAL), 2085 elvitegravir (EVG) and 929 dolutegravir (DTG)). PWH starting INSTI-based regimens had mean estimated five-year weight change of +5.9kg, compared to +3.7kg for NNRTI and +5.5kg for PI. Among PWH starting INSTI drugs, mean estimated two-year weight change was +7.2kg for DTG, +5.8kg for RAL and +4.1kg for EVG. Women, persons with lower baseline CD4+ cell counts, and those initiating INSTI-based regimens had higher odds of &gt;10% body weight increase at two years (adjusted odds ratio&nbsp;=&nbsp;1.37, 95% confidence interval: 1.20 to 1.56 vs. NNRTI).ConclusionsPWH initiating INSTI-based regimens gained, on average, more weight compared to NNRTI-based regimens. This phenomenon may reflect heterogeneous effects of ART agents on body weight regulation that require further exploration