Acute and 2?days delayed effects of exhaustive stretch-shortening cycle exercise on barefoot walking and running patterns

This study investigated the acute and 2?days delayed influences of exhaustive stretch-shortening cycle exercise (SSC) on barefoot walking and running gait patterns. The SSC exercise was performed on a sledge apparatus, on which the subjects (N?=?10) repeated until exhaustion intermittent series of 25 bilateral submaximal rebounds. Maximal drop-jumps and submaximal barefoot treadmill walking and running were performed before (PRE) and after (POST) the exhaustive exercise and repeated 48?h (D2) later. Electromyographic activity and 3D kinematics of the right lower limb and foot were recorded for 15?s at gait initiation (BEG) and at the end (END: at 3?min of walk and 5?min of run). The exhaustive SSC exercise resulted in 6% reductions in maximal drop jump performance at POST and D2, and affected mostly both gait patterns at D2. The walking pattern presented compensatory neural adjustments within the triceps surae muscle group. This expected pain-induced protective strategy of the soleus muscle was sufficient to preserve the kinematics pattern. The running condition revealed a major knee strategy, which might support the concept of pain protective strategy of knee extensor muscles at the expense of impact cushioning. Regardless the testing session, most parameters showed fatigue-induced changes at gait initiation (BEG), which were opposite to subsequent BEG to END adjustments. This is likely to support anticipatory strategies rather than progressive adjustments during the exercise.     

Sensory regulation of quadrupedal locomotion: a top-down or bottom-up control system?

Propriospinal pathways are thought to be critical for quadrupedal coordination by coupling cervical and lumbar central pattern generators (CPGs). However, the mechanisms involved in relaying information between girdles remain largely unexplored. Using an in vitro spinal cord preparation in neonatal rats, Juvin and colleagues (Juvin et al. 2012) have recently shown sensory inputs from the hindlimbs have greater influence on forelimb CPGs than forelimb sensory inputs on hindlimb CPGs, in other words, a bottom-up control system. However, results from decerebrate cats suggest a top-down control system. It may be that both bottom-up and top-down control systems exist and that the dominance of one over the other is task or context dependent. As such, the role of sensory inputs in controlling quadrupedal coordination before and after injury requires further investigation.     

The autopsy: complete or not complete?

Less invasive or non-invasive alternatives to the complete autopsy have been sought for some time, and a range of methods, ranging from needle sampling to endoscopy to magnetic resonance imaging, have been considered. Evaluations of these methods are few and far between, but generally confirm the predictable conclusion that incomplete autopsies provide incomplete information. It is not difficult to envisage a situation whereby pressure for non-invasive autopsies will allow them to become prevalent, whether properly evaluated or not. However, used appropriately, non-invasive or less invasive autopsies may be valuable tools capable of answering specific questions in situations where it is not possible to perform a complete autopsy.     

The ubiquitin proteasome system in neurodegenerative diseases: Culprit,accomplice or victim?

A shared hallmark for many neurodegenerative disorders is the accumulation of toxic protein species which is assumed to be the cause for these diseases. Since the ubiquitin proteasome system (UPS) is the most important pathway for selective protein degradation it is likely that it is involved in the aetiology neurodegenerative disorders. Indeed, impairment of the UPS has been reported to occur during neurodegeneration. Although accumulation of toxic protein species (amyloid β) are in turn known to impair the UPS the relationship is not necessarily causal. We provide an overview of the most recent insights in the roles the UPS plays in protein degradation and other processes. Additionally, we discuss the role of the UPS in clearance of the toxic proteins known to accumulate in the hallmarks of neurodegenerative diseases. The present paper will focus on critically reviewing the involvement of the UPS in specific neurodegenerative diseases and will discuss if UPS impairment is a cause, a consequence or both of the disease.     

The effect of social roles on mental health: a matter of quantity or quality?

The effect of social roles (partner, parent, worker) on mental health may depend on the total number or the quality of the individual occupied social roles. With longitudinal data from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), the effect of the number and quality of occupied social roles on mental health over three years was examined among 2471 men and women aged 25-55 years without mental disorders at baseline. Mental health was assessed using 3-year change in the SF-36 mental health scale as well as using the 3-year incidence of anxiety and depressive disorders defined by DSM-III criteria. The quality of social roles was assessed by the GQSB (Groningen Questionnaire Social Behavior). The number of social roles had no significant effect on the risk of developing depressive and anxiety disorders, but particularly the partner-role had a significant positive effect on mental health (beta of mental health=1.19, p=0.01; HR of incident disorders=0.75, 95% CI:0.51-1.00, p=0.05). A good quality of each of the three social roles was associated with higher levels of mental health and lower risks of incident disorders over 3 years. More than the number of social roles, knowledge about social role quality might provide opportunities for prevention of depressive and anxiety disorders.     

The perceptual control of goal-directed locomotion: a common control architecture for interception and navigation?

Intercepting a moving object while locomoting is a highly complex and demanding ability. Notwithstanding the identification of several informational candidates, the role of perceptual variables in the control process underlying such skills remains an open question. In this study we used a virtual reality set-up for studying locomotor interception of a moving ball. The subject had to walk along a straight path and could freely modify forward velocity, if necessary, in order to intercept—with the head—a ball moving along a straight path that led it to cross the agents displacement axis. In a series of experiments we manipulated a local (ball size) and a global (focus of expansion) component of the visual flow but also the egocentric orientation of the ball. The experimental observations are well captured by a dynamic model linking the locomotor acceleration to properties of both global flow and egocentric direction. More precisely the changes in locomotor velocity depend on a linear combination of the change in bearing angle and the change in egocentric orientation, allowing the emergence of adaptive behavior under a variety of circumstances. We conclude that the mechanisms underlying the control of different goal-directed locomotion tasks (i.e. steering and interceptive tasks) could share a common architecture.     

The comet assay: Genotoxic damage or nuclear fragmentation?

The single cell gel electrophoresis (SCGE) or comet assay is based on the assumption that comet images result from genotoxic damage that ultimately generate DNA single- or double-strand breaks. A criticism of the assay is that some or all of the comet images may be the result of apoptosis-mediated nuclear fragmentation. The objective of this study was to determine if mutagen-induced DNA damage leading to strand breakage observed in the SCGE assay was repairable or was due to nonrepairable nuclear fragmentation. Chinese hamster ovary cells were treated with ethylmethanesulfonate, 2-acetoxyacetylaminofluorene, or H(2)O(2). These mutagens induce genetic damage by different molecular mechanisms. One group of SCGE slides was prepared immediately after treatment, while parallel treated cultures were repeatedly washed and allowed to undergo liquid holding recovery for DNA repair. It was hypothesized that cells with genotoxic damage can repair their genomic DNA, while apoptotic cells cannot reverse nuclear fragmentation. We found a significant decrease in the tail moments of nuclei from mutagen-treated cells after 4 hr of liquid holding. However, this measurement may represent only those cells capable of repair. Apoptotic cells may continue DNA fragmentation during the recovery time and this DNA may become so diffuse that the nuclei disappear after electrophoresis. To overcome this possible artifact, images of nuclei were captured before and after alkaline electrophoresis. Constellations of nuclei were located on SCGE slides by their coordinates on the microscope stage. We found that no nuclei were lost due to apoptotic nuclear fragmentation and DNA migration. Even the so-called "hedgehog" comet images with extreme DNA damage were not lost during liquid holding. These data support the conclusion that mutagen-induced DNA damage is the principal cause of the damage measured in the comet assay.     

The Automated Clinical Microbiology Laboratory: Fact or Fantasy?

Automated chemistry laboratories dependent on robotic processes are the standard in both academic and large community hospital settings. Diagnostic microbiology manufacturers are betting that robotics will be used for specimen processing, plate reading, and organism identification in the near future. These systems are highly complex and have large footprints and hefty price tags. However, they are touted as being more efficient, rapid, and accurate than standard processes. Certain features, such as image collection, are highly innovative. Hospital administrators may be swayed to institute these new systems because of the promise of the need for fewer skilled workers, higher throughput, and greater efficiency. They also may be swayed by the fact that workers with the requisite clinical microbiology skills are becoming more difficult to find, and this technology should allow fewer skilled workers to handle larger numbers of cultures. In this Point-Counterpoint, Nate Ledeboer, Medical Director, Clinical Microbiology and Molecular Diagnostics, Dynacare Laboratories, and Froedtert Hospital, Milwaukee, WI, will explain why he believes that this approach will become widespread, while Steve Dallas of the University of Texas Health Science Center San Antonio explains why he thinks that this automation may not become widely used.

• J Clin Microbiol. 2014 Sep; 52(9): 3140–3146.
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• Sub-article 1

2014 Sep; 52(9): 3140–3146. doi: 10.1128/JCM.00686-14 Copyright and License information DisclaimerCopyright notice     

The Russian Biological Weapons Program: Vanished or Disappeared?

The legacy and arsenal of biological weapons Russia inherited from USSR in 1991 became a lingering unsolved issue, in terms of a prime strategic arm that ought to be eliminated, advisably, in accordance with the Biological Weapons Convention Russia is committed to, and considering further undertakings and declarations made by the Russian regime. Indeed, that inheritance was created by USSR as a powerful, highly sophisticated component of utmost importance within the Soviet military paradigm, based on a wide spectrum of virulent, stabilized pathogens and toxins plus delivery systems. Moreover, remarkably advanced biotechnologies were thus applied to procure stockpiles of military-grade pathogens and toxins. Yet, an intriguing debate aroused with regard to the extent of the weaponized biological inventory accumulated by USSR, as well as the in effect attitude of Russia towards perpetuating or wiping out that inheritance. It turned out to form a far reaching and challenging complexity, both strategically and scientifically. The present study concentrates on the strategic as well as scientific spheres shaping that overall issue at large, attempting to thoroughly analyze it through an innovative methodology. One main conclusion thereby reached at is that the Russian military still poses a potential menance, in terms of both stockpiled, probably deployable biological weapons, and prevailing production capacities.     

The Russian biological weapons program: vanished or disappeared?

The legacy and arsenal of biological weapons Russia inherited from USSR in 1991 became a lingering unsolved issue, in terms of a prime strategic arm that ought to be eliminated, advisably, in accordance with the Biological Weapons Convention Russia is committed to, and considering further undertakings and declarations made by the Russian regime. Indeed, that inheritance was created by USSR as a powerful, highly sophisticated component of utmost importance within the Soviet military paradigm, based on a wide spectrum of virulent, stabilized pathogens and toxins plus delivery systems. Moreover, remarkably advanced biotechnologies were thus applied to procure stockpiles of military-grade pathogens and toxins. Yet, an intriguing debate aroused with regard to the extent of the weaponized biological inventory accumulated by USSR, as well as the in effect attitude of Russia towards perpetuating or wiping out that inheritance. It turned out to form a far reaching and challenging complexity, both strategically and scientifically. The present study concentrates on the strategic as well as scientific spheres shaping that overall issue at large, attempting to thoroughly analyze it through an innovative methodology. One main conclusion thereby reached at is that the Russian military still poses a potential menance, in terms of both stockpiled, probably deployable biological weapons, and prevailing production capacities.     

The negative autopsy: Sudden cardiac death or other?

One of the most frustrating challenges faced by the forensic pathologist is the inability to determine the cause of death in a young person previously thought healthy. The four steps in the investigation of a sudden death include obtaining the history and scene information, performing a gross and microscopic autopsy, performing appropriate laboratory tests, and making the diagnosis. When examining the heart grossly it is important to preserve the anatomic landmarks, section the coronary arteries closely, and recognize lethal abnormalities such as anomalous origin of the coronary arteries. Specimens useful for toxicologic analysis include whole blood, serum, vitreous humor, gastric contents, bile, urine a purple top tube of blood, and frozen myocardium and spleen. Lethal cardiac diseases with minimal or no anatomic findings include Brugada and Garg's syndromes, the long QT syndrome, and Wolff–Parkinson–White (WPW) syndrome. Consultation with other experts, including cardiac pathologists, cardiologists, electrophysiologists, and molecular biologists, may be helpful in determining a cause of death.