Modular hip exoskeleton improves walking function and reduces sedentary time in community-dwelling older adults

Numerous studies showed that postural balance improves through light touch on a stable surface highlighting the importance of haptic information, seemingly downplaying the mechanical contributions of the support. The present study examined the mechanical effects of canes for assisting balance in healthy individuals challenged by standing on a beam. Sixteen participants supported themselves with two canes, one in each hand, and applied minimal, preferred, or maximum force onto the canes. They positioned the canes in the frontal plane or in a tripod configuration. Statistical analysis used a linear mixed model to evaluate the effects on the center of pressure and the center of mass. The canes significantly reduced the variability of the center of pressure and the center of mass to the same level as when standing on the ground. Increasing the exerted force beyond the preferred level yielded no further benefits, although in the preferred force condition, participants exploited the altered mechanics by resting their arms on the canes. The tripod configuration allowed for larger variability of the center of pressure in the task-irrelevant anterior–posterior dimension. High forces had a destabilizing effect on the canes: the displacement of the hand on the cane handle increased with the force. Given this static instability, these results show that using canes can provide not only mechanical benefits but also challenges. From a control perspective, effort can be reduced by resting the arms on the canes and by channeling noise in the task-irrelevant dimensions. However, larger forces exerted onto the canes can also have destabilizing effects and the instability of the canes needs to be counteracted, possibly by arm and shoulder stiffness. Insights into the variety of mechanical effects is important for the design of canes and the instructions of how to use them.     

G1 domain of aggrecan cointernalizes with hyaluronan via a CD44-mediated mechanism in bovine articular chondrocytes

OBJECTIVE: To determine whether aggrecan fragments bound to hyaluronan (HA) can be retained and internalized by articular chondrocytes and whether these events are dependent on HA and its receptor, CD44. An additional objective was to determine whether partial degradation of aggrecan is a prerequisite for internalization. METHODS: Binding and internalization of a variety of fluorescein isothiocyanate (FITC)- or biotin-labeled HA/proteoglycan probes were investigated on normal bovine articular cartilage chondrocytes, bovine articular chondrocytes transfected with a dominant-negative construct of CD44, or COS-7 cells transfected with wild-type CD44. The probes were defined as being internalized by the presence of label associated with the cells following extensive trypsinization of the cell surface. RESULTS: Biotinylated aggrecan fragments bound to FITC-HA were cointernalized in bovine articular chondrocytes or COS-7 cells transfected with CD44. Intracellular vesicles containing FITC-HA colocalized with a fluorescent probe for lysosomes. The internalization of the aggrecan fragments was dependent on the presence of HA as well as the presence of functional CD44. Intact aggrecan/FITC-HA complexes bound to the cell surface but were not internalized. However, following brief trypsin digestion of the aggrecan/HA complex, the remaining proteoglycan fragments were bound and internalized. CONCLUSION: Partially degraded aggrecan fragments (e.g., aggrecan G1 domains bound to HA) can be internalized by articular chondrocytes via a mechanism involving HA/CD44-mediated endocytosis. Further, the presence of an intact aggrecan monomer bound to HA inhibits the internalization of HA as well as HA-bound fragments.     

Biopsy of the prostate guided by transrectal ultrasonography: early experience in a teaching community hospital.

Transrectal ultrasonography (TRUS) was used to guide 277 biopsies of the prostate in 182 patients. The Bard Biopty system was used. Of these 182 patients, 107 (59%) had benign changes, and 75 (41%) had malignant lesions. Of those with cancer, 40% (30/75) had negative results of digital rectal examination (DRE). The cancer detection rate by TRUS was 40.7%, and by DRE alone it was 24.2%. Use of TRUS before transurethral resection of the prostate (TURP) in 47 patients with negative findings on DRE yielded 22 cancerous lesions (47%). We advocate this method in patients with abnormalities detected on DRE or with elevated levels of prostate-specific antigen or prostatic acid phosphatase, and as preoperative screening in patients having TURP because of the potential impact of a preoperative diagnosis of cancer upon the choice of treatment.     

Nurturing the Genius of Genes: The New Frontier of Education, Therapy, and Understanding of the Brain

Genes dance. They dance with culture. Theydance with environment. Genes act on the world through the brain, mind and behavior. Historically, psychologists, therapists,educators and most lay people have understoodgenes in the context of Gregor Mendel'sexperiments, which were only partiallyexplained to us. While many studies show thatbrain structures and behaviors have quiterobust influences from inheritance, mostbehavior is not influenced in the classic waywe were taught in our introduction to genetics– which has been revolutionized by molecularstudies and understandings that most of theimportant genes of everyday life arequantitative, or polygenic.Popular culture and naïve theory has a verysimplistic view of genes. They are bad,impolite and vaguely anti-democratic if notsinister. A very simple truth exists, however.Were it not for the genes of our grandparents,no one would be reading this article.This article introduces the reader to an ideathat emerges from evolutionary psychology andbehavior genetics, which may turn our thinkinginside out. For the most part, genes are giftsof nature to solve problems, and to hedge a beton the future. Most true genetic diseases,regulated by the classic processes that Mendelobserved, are extremely rare – typically belowone in several hundred. Most of the behaviorsthat cause us grief or joy in our homes,schools and communities and with some form ofgenetic contribution happen far more often –3%, 5%, 10% or more of the time in thepopulation. If such behaviors were ``defects'harming our reproductive success, Mother Naturewould have quickly made short work of thosegenes in a handful of generations. The factthat many of the genes related to thesebehaviors and subtle changes in the brain seemto have been recent changes (pejorativelycalled by some ``mutations') in the past fewthousand years implies that these changes are insome sense Nature's Gifts.Gifts are to be treasured, saved and perhapspassed on. Sometimes a gift may be burdensome. This paper is about reframing and explainingadvances in science in the past 10 years or so,parallel to the brain imaging studies. Themolecular studies, explored in the context ofevolutionary psychology and behavioral geneticsprovide a new model for human development,enhancing our understanding of more traditionalviews of human phylogeny and ontogeny. Thesame molecular studies, when framed in thecontext of twin, adoption and longitudinalstudies, provide new insights for parenting,schools, community and therapy.     

How are bariatric patients coping during the coronavirus disease 2019 (COVID-19) pandemic? Analysis of factors known to cause weight regain among postoperative bariatric patients

BackgroundThe global coronavirus disease 2019 (COVID-19) pandemic is wreaking havoc on society. Bariatric patients are more prone to severe infection due to their high body mass index (BMI) and are more vulnerable to the effects of isolation, such as depression or disruption of their health habits.ObjectivesTo quantify the impact of self-quarantine on bariatric patients and self-quarantine’s relationship with weight gain.SettingAcademic hospital, United States.MethodsA 30-item survey examining several known contributors to weight regain was distributed among the postoperative bariatric patients of our clinic. Changes in eating habits, exercise, depression, social support, loneliness, and anxiety were studied, among others.ResultsA total of 208 patients completed the survey (29.3% response rate). A large percentage of patients reported increases in their depression (44.2%), loneliness (36.2%), nervousness (54.7%), snacking (62.6%), loss of control when eating (48.2%), and binge eating (19.5%) and decreases in their social support (23.2%), healthy food eating (45.5%), and activity (55.2%). Difficulty in accessing vitamins was reported by 13%. Patients more than 18 months out of surgery regained more than 2 kg during an average of 47 days. Risk factors for weight regain were found to be loss of control when eating, increases in snacking and binge eating, reduced consumption of healthy food, and reduced physical activity.ConclusionBariatric patients are negatively affected by the COVID-19 pandemic and subsequent social isolation on many levels. This patient population is vulnerable to crisis situations; thus, additional intervention is needed to address behaviors that lead to weight regain.