To understand how mutations in thick filament proteins such as cardiac myosin binding protein-C or titin, cause familial hypertrophic cardiomyopathies, it is important to determine the structure of the cardiac thick filament. Techniques for the genetic manipulation of the zebrafish are well established and it has become a major model for the study of the cardiovascular system. Our goal is to develop zebrafish as an alternative system to the mammalian heart model for the study of the structure of the cardiac thick filaments and the proteins that form it. We have successfully isolated thick filaments from zebrafish cardiac muscle, using a procedure similar to those for mammalian heart, and analyzed their structure by negative-staining and electron microscopy. The isolated filaments appear well ordered with the characteristic 42.9 nm quasi-helical repeat of the myosin heads expected from x-ray diffraction. We have performed single particle image analysis on the collected electron microscopy images for the C-zone region of these filaments and obtained a three-dimensional reconstruction at 3.5 nm resolution. This reconstruction reveals structure similar to the mammalian thick filament, and demonstrates that zebrafish may provide a useful model for the study of the changes in the cardiac thick filament associated with disease processes.
Energy drinks consumption continues to grow since its Background: appearance in the United States in 1997. Available evidence indicates that caffeine, their main ingredient, can alter the central nervous system (CNS). However, it is unknown how energy drinks alter the CNS postural control mechanism. The purpose of this study was to investigate how energy drinks can affect postural control after sensory perturbations during stance. 20 healthy adults, (11 males; 9 females) averaging 26.1 years of Methods: age, stood on a MatScan™ pressure mat, which measured center of pressure (CoP), anteroposterior (AP) and mediolateral (ML) postural sways during eight different balance tests (BALT's). BALT's were designed to alter or cancel the systems involved in postural control: visual, vestibular and somatosensory. Subjects were randomly assigned to a caffeine group and an energy drink group. MANOVA analysis was performed for all variables of interest.In the caffeine group, the AP sway of the Eyes Closed test on a stable Results: surface was statistically significant. In the energy drinks group, we observed a general tendency of participants to increase CoP slightly, AP and ML sway in most of the BALT's after the consumption of an energy drink. However, this increase was not statistically significant. These results suggest that in healthy young adults, the sensory re-weighting mechanism can overcome postural perturbation and maintain overall postural control.We observed an overall tendency to increase postural instability Conclusions: after the ingestion of energy drinks.
Undergraduate students often have difficulty relating the Anatomy and Physiology (A&P) course to their future careers, which may lead to difficulties in graduate school. Thus, the purpose of the Anatomy Observational Outreach (AOO) was to help students make the connection and application between the information presented in A&P labs and real human cadaver, which could encourage students to pursue graduate degrees. The outreach consisted of 99 undergraduate A&P students from Texas Woman’s University in the biology, nursing, kinesiology, health studies, physical therapy, and occupational therapy departments. The methodology consisted of a 30-minute orientation, a graduate student panel, a Q&A session, a 60-minute cadaver observation, and Anatomage table demonstration, amongst others. The impact of AOO was measured by 10-question pre-tests and identical post-tests (1 point each) along with a survey at the end. The tests result demonstrated a significant increase [t(62)=-9.3, p=0.001] in anatomical knowledge. The survey results showed that out of 99 participants, 84% of the students interested in applying to graduate school, 32% of students felt that all of the teaching tools were useful, while 68% concluded the cadaver prosections were the most potent sole educational aid. 65% of the students were ethnic minorities, and 97% were gender minorities. We conclude that AOO yielded distinguished results in retention, and application of A&P knowledge, along with increased interest and excitement for pursuing a STEM and Allied Health degrees.
Patients with diabetes have been shown to suffer from Background: increased fall risk. Research shows that this risk is higher on irregular surfaces. Existing studies evaluate gait on irregular surfaces, such as stairs, asphalt, grass and stones. This study evaluates gait parameters in individuals with diabetes mellitus type II (DMII) with no history of peripheral neuropathy, while ascending and descending a ramp at an imposed speed, and compares them with healthy controls.Fifteen healthy volunteer participants and fifteen participants with Methods: DMII and no peripheral neuropathy (females and males) between the ages of 40-65 were recruited for this study. Participants walked three times at 100 bpm while ascending and descending a wooden ramp. Temporospatial and kinematic parameters were analyzed.We observed minimal changes in temporospatial and kinetic Results: parameters in people with controlled DMII with no evidence of peripheral neuropathy.Focusing on individuals with controlled DMII allowed us to Conclusion: determine if only the diagnosis of diabetes without peripheral neuropathy influenced gait parameters. Clinicians and researchers should focus their assessments on neuromuscular activation during this stage of the condition, thus preventing complications, such as abnormal gait, that increases the risk for falls.
People diagnosed with HIV may exhibit orthostatic Background: hypotension (OH) as a result of the infection and of secondary effects of medications. Such impairments are attributed to autonomic nervous system (ANS) deficits. The purpose of this study was to assess OH during a balance sensory condition test (SCT) and evaluate the role of the cardiac autonomic system, regarding blood pressure (BP) and heart rate (HR), during this balancing task. We hypothesized that BP and heart rate would rise with an increase in postural instability, thus revealing OH.: Eight individuals diagnosed with HIV were recruited from a Methods community health center in the area of San Juan, Puerto Rico. BP and HR were measured after 5 minutes of sitting, immediately after standing up and 1 minute after this, during the SCT. A t-test was used to assess the difference between BP in sitting, BP in standing, and BP while performing the SCT. HR was also evaluated the same way.There was an increase of more than 10 mmHg in systolic BP Results: (SBP) from sitting compared to standing while performing the SCT (p≤0.01). Likewise, HR and SBP standing versus standing during the SCT increased significantly (p≤0.01).The results of this study show that the ANS may be impaired Conclusion: in people with HIV. Cohen JA, Miller L, Polish L: Orthostatic hypotension in human immunodeficiency virus infection may be the result of generalized autonomic nervous system dysfunction. J Acquir Immune Defic Syndr. 1991; 4(1): 31-3. PubMed Abstract | Publisher Full Text Dymarek R, Ptaszkowski K, Słupska L, et al.: [Physiotherapy potentials improve the calf muscle pump function in chronic venous insufficiency]. Wiad Lek. 2014; 67(2 Pt 1): 112-8. PubMed Abstract Ogoh S, Volianitis S, Nissen P, et al.: Carotid baroreflex responsiveness to headup tilt-induced central hypovolaemia: effect of aerobic fitness. J Physiol. 2003; 551(Pt 2): 601-8. PubMed Abstract | Publisher Full Text | Free Full Text Ogoh S, Yoshiga CC, Secher NH, et al.: Carotid-cardiac baroreflex function does not influence blood pressure regulation during head-up tilt in humans. J Physiol Sci. 2006; 56(3): 227-33. PubMed Abstract | Publisher Full Text Recek C: Calf pump activity influencing venous hemodynamics in the lower extremity. Int J Angiol. 2013; 22(1): 23-30. PubMed Abstract | Publisher Full Text | Free Full Text Robinson-Papp J, Sharma S, Simpson DM, et al.: Autonomic dysfunction is common in HIV and associated with distal symmetric polyneuropathy. J Neurovirol. 2013; 19(2): 172-80.PubMed Abstract | Publisher Full Text | Free Full Text
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