The interactive effect of subjective age and subjective distance-to-death on psychological distress of older adults

Objectives: Subjective age refers to how young or old people experience themselves to be, while subjective distance-to-death reflects how far or close they experience themselves to be from their death. The present study examined whether subjective age and subjective distance-to-death interact in predicting psychological distress.

Method: A sample of 1073 community-dwelling older adults at the age range of 50–86 (M = 58.1, SD = 5.3) evaluated their subjective age, subjective distance-to-death, psychological distress, and rated several measures of physical health.

Results: After controlling for background characteristics and physical health indices, perceiving death as far and reporting younger subjective age predicted lower psychological distress. The combination of feeling close to death and older subjective age was related to the highest ratings of psychological distress. Moreover, the effect of subjective distance-to-death on psychological distress was mitigated by younger subjective age.

Conclusion: The findings underscore the importance of an integrative view of two time perspectives – one that focuses on time since birth and another that concerns time left till death – to psychological distress of older adults.     

Three-dimensional imaging improves surgical skill performance in a laparoscopic test model for both experienced and novice laparoscopic surgeons

Study objective

The objective of this study was to evaluate and compare the impact of three-dimensional (3D) imaging system on the performance of basic laparoscopic tasks in a test model by novice and experienced surgeons.

Design

Three tasks were performed in a test model by 30 surgeons, 15 experienced surgeons, and 15 with minimal laparoscopic experience. The tasks were performed using 2D and 3D vision systems.

Design classification

Canadian Task Force II-1.

Subjects

Fifteen experienced laparoscopic surgeons and fifteen novices with minimal laparoscopic experience.

Measurements

Performance times were recorded using both two-dimensional and 3D imaging system for each task.

Main results

Performance time for all skills was significantly (P < 0.02) shorter when using 3D imaging system. Performance times were reduced by 18–31 % using 3D imaging for all participants. Experienced surgeons performed the tasks faster and showed similar improvement while using 3D imaging system.

Conclusion

3D vision systems allow for significant improvement in performance times of basic laparoscopic tasks in a test model for both inexperienced and advanced laparoscopic surgeons. Experienced surgeons benefit as much as novices from 3D imaging system. This benefit should be weighed against the disadvantages of the 3D vision systems, mainly cost, decreased light, eye strain, headaches, and shorter focal lengths.     

Characterization and antibacterial properties of N-halamine-derivatized cross-linked polymethacrylamide nanoparticles

N-halamine-derivatized cross-linked polymethacrylamide nanoparticles with sizes ranging between 18 ± 2.0 and 460 ± 60 nm were prepared via surfactant-free dispersion co-polymerization of methacrylamide (MAA) and the cross-linking monomer N,N-methylenebisacrylamide (MBAA) in an aqueous continuous phase, followed by a chlorination process using sodium hypochlorite. The effect of various polymerization parameters (monomer concentration, initiator type and concentration, polymerization duration, polymerization temperature, and the weight ratio [MBAA]/[MAA]) on the size and size distribution of the produced cross-linked P(MAA–MBAA) nanoparticles was elucidated. The effect of various chlorination parameters (hypochlorite concentration, chlorination period and temperature) on the bound oxidative chlorine atom (Cl) content of the P(MAA–MBAA) nanoparticles was also investigated. The bactericidal activity of these chloramine-derivatized nanoparticles was tested against two common bacterial pathogens (Escherichia coli and Staphylococcus aureus), and they were found to be highly potent. Furthermore, these nanoparticles also exerted their antimicrobial activity against multi-drug resistant (MDR) bacteria, further demonstrating their efficacy.     

Stent-based percutaneous coronary interventions in small coronary arteries

A third to half of all percutaneous coronary interventions involve small diameter vessels of less than 3 mm. Small vessel size is a predictor of restenosis after balloon angioplasty, as well as after stent placement. Stents deployed in small arteries, have a higher metal-to-artery ratio; this may increase the risk of sub-acute thrombosis or restenosis. Various studies have shown that stent design, stent coating, and stent strut thickness may determine event-free survival. Dedicated stents for small vessels with less amount of metal, appropriate expansion to the vessel size with correct radial force and cells morphology, and less prothrombotic properties, may further improve the results of stenting in this setting (thinner struts, fewer cells, or loops per circumference). This review provides an update on the current status, review the major trials and define the clinical utility of small vessel stenting, particularly in the era of drug-eluting stents.     

Spondylosis in sand rats: a model of intervertebral disc degeneration and hyperostosis

This study defines gross, histopathologic, and radiologic changes associated with intervertebral disc degeneration in a spontaneously occurring form of the disease in aging sand rats (Psammomys obesus). Sand rats (male/female) fed lab chow supplemented with desert salt bush were sacrificed at periods of 3-30 months. Lateral thoracolumbar spine films were obtained. At sacrifice, spines were surgically exposed and gross findings were recorded; after fixation/decalcification, histopathologic studies were carried out using hematoxylin and eosin, and Safranin-O with fast green counterstain. Metabolic studies included correlations of pathologic and radiologic findings with blood glucose and insulin levels. Disc-space narrowing and subchondral endplate sclerosis increased radiologically with age, with more severe lower lumbar disc lesions. Ligamentous calcifications ventral to involved discs and caudal vertebrae were common. Disc thinning and anterior vertebral bony/cartilaginous spurs were more marked with age. Microscopy revealed loss of nucleus pulposus physaliform cells, chondrocyte replication, disc necrosis, and ossification. Hyperglycemia with and without hyperinsulinemia was common. No statistically significant differences in pathologic findings were noted, neither in diabetic versus nondiabetic nor in hyperinsulinemic animals. The sand rat is a model of disc degeneration; similarities with possible overlap with diffuse idiopathic skeletal hyperostosis syndrome were noted.     

HBV-RNA,Quantitative HBsAg,Levels of HBV in Peripheral Lymphocytes and HBV Mutation Profiles in Chronic Hepatitis B

A comprehensive characterization of chronic HBV (CHB) patients is required to guide therapeutic decisions. The cumulative impact of classical and novel biomarkers on the clinical categorization of these patients has not been rigorously assessed. We determined plasma HBV-RNA and HBsAg levels, HBV in peripheral lymphocytes (PBMCs) and HBV mutation profiles in CHB patients. Patient demographics (n = 139) and classical HBV biomarkers were determined during a clinical routine. HBV-RNA in plasma and HBV-DNA in PBMCs were determined by RT-PCR. HBsAg levels were determined using Architect. In samples with HBV-DNA viral load >1000 IU/mL, genotype mutations in precore (PC), basal core promoter (BCP), HBsAg and Pol regions were determined by sequencing. Most patients (n = 126) were HBeAg-negative (HBeAgNeg) with significantly lower levels of HBV-RNA, HBV-DNA and HBsAg compared to HBeAg-positive (HBeAgPos) patients (p < 0.05). HBV genotype D prevailed (61/68), and >95% had BCP/PC mutations. Escape mutations were identified in 22.6% (13/63). HBeAgNeg patients with low levels of HBsAg (log IU ≤ 3) were older and were characterized by undetectable plasma HBV-DNA and undetectable HBV-RNA but not undetectable HBV-DNA in PBMCs compared to those with high HBsAg levels. In >50% of the studied HBeAgNeg patients (66/126), the quantitation of HBsAg and HBV-RNA may impact clinical decisions. In conclusion, the combined assessment of classical and novel serum biomarkers, especially in HBeAgNeg patients, which is the largest group of CHB patients in many regions, may assist in clinical decisions. Prospective studies are required to determine the real-time additive clinical advantage of these biomarkers.