Project description:This paper reports the kinematic, kinetic and electromyographic (EMG) dataset of human locomotion during level walking at different velocities, toe- and heel-walking, stairs ascending and descending. A sample of 50 healthy subjects, with an age between 6 and 72 years, is included. For each task, both raw data and computed variables are reported including: the 3D coordinates of external markers, the joint angles of lower limb in the sagittal, transversal and horizontal anatomical planes, the ground reaction forces and torques, the center of pressure, the lower limb joint mechanical moments and power, the displacement of the whole body center of mass, and the surface EMG signals of the main lower limb muscles. The data reported in the present study, acquired from subjects with different ages, represents a valuable dataset useful for future studies on locomotor function in humans, particularly as normative reference to analyze pathological gait, to test the performance of simulation models of bipedal locomotion, and to develop control algorithms for bipedal robots or active lower limb exoskeletons for rehabilitation.
Project description:BackgroundCOVID-19 (severe acute respiratory syndrome coronavirus 2) infected patients have increased risk for thrombotic events, which initially may have been under recognized. The existence of cardiovascular emboli can be directly life threatening when obstructing the blood flow to vital organs such as the brain or other parts of the body. The exact mechanism for this hypercoagulable state in COVID-19 patients yet remains to be elucidated.Case summaryA 72-year-old man critically ill with COVID-19 was diagnosed with a free-floating and mural thrombus in the thoracic aorta. Subsequent distal embolization to the limbs led to ischaemia and necrosis of the right foot. Treatment with heparin and anticoagulants reduced thrombus load in the ascending and thoracic aorta.DiscussionOne-third of COVID-19 patients show major thrombotic events, mostly pulmonary emboli. The endothelial expression of angiotensin-converting enzyme-2 receptors makes it feasible that in patients with viraemia direct viral-toxicity to the endothelium of also the large arteries results in local thrombus formation. Up to date, prophylactic anticoagulants are recommended in all patients that are hospitalized with COVID-19 infections to prevent venous and arterial thrombotic complications.
Project description:Brain asymmetries are a widespread phenomenon among vertebrates and show a common behavioural pattern. The right hemisphere mediates more emotional and instinctive reactions, while the left hemisphere deals with elaborated experience-based behaviours. In order to achieve a lateralized behaviour, each hemisphere needs different information and therefore different representations of the world. However, how these representations are accomplished within the brain is still unknown. Based on the pigeon's visual system, we present experimental evidence that lateralized behaviour is the result of the interaction between the subtelencephalic ascending input directing more bilateral visual information towards the left hemisphere and the asymmetrically organized descending telencephalic influence on the tecto-tectal balance. Both the bilateral representation and the forebrain-modulated information processing might explain the left hemispheric dominance for complex learning and discrimination tasks.
Project description:The spinal cord contains many descending and ascending longitudinal tracts whose development appears to be controlled by distinct guidance systems. We identified a population of dorsal spinal neurons marked by coexpression of the transcription factor Zic2 and the guidance receptor EphA4. Zic2+;EphA4+ neurons are surrounded by mechanosensory terminals, suggesting innervation by mechanoreceptor afferents. Their axons form an ipsilateral ascending pathway that develops during embryogenesis and projects within the ventral aspect of the dorsal funiculus, the same location as the descending corticospinal tract (CST), which develops postnatally. Interestingly, the same guidance mechanism, namely, ephrinB3-induced EphA4 forward signaling, is required for the guidance of both ascending and descending axon tracts. Our analysis of conditional EphA4 mutant mice also revealed that the development of the dorsal funiculus occurs independently of EphA4 expression in descending CST axons and is linked to the distribution of Zic2+;EphA4+ spinal neurons and the formation of the ascending pathway.
Project description:Stairs are among the most hazardous locations, and stair descending contributes to a high risk of falls among the elderly under dual-task (DT) conditions. The purpose of this study was to determine whether the practitioners of Tai Chi (TC), one type of mind-body exercise, have lower fall risks under DT conditions during stair descending, compared with their no-exercise (NE) counterparts. Fifteen TC practitioners with at least 10 years of experience in TC and fifteen NE participants were recruited in this study. They were asked to descend a six-step staircase under single-task (ST) and DT conditions. An eight-camera motion analysis system and two force plates were used for data collection. Results showed group by DT interactions in walking velocity (p = 0.016) and center of mass-center of pressure inclination angle (COM-COP IA) in the anteroposterior directions (p = 0.026). Group effects observed with foot clearance (p = 0.031), trunk (p = 0.041) and head (p = 0.002) tilt angles, and COM-COP IA in the mediolateral (p = 0.006) directions. Significant DT effects only detected in foot clearance (p = 0.004). Although both groups of participants adopted a more cautious gait strategy under the dual-task condition, the TC practitioners were less influenced by the DT paradigm than their NE counterparts. Our observations indicated that TC practitioners have lower fall risks under DT conditions during stair descending.
Project description:The Nigrostriatal pathway (NSP) is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.
Project description:BACKGROUND:Obesity is a risk factor for colorectal cancer, yet metabolic distinctions between healthy right and left colon tissue, before cancer is diagnosed, remains largely unknown. This study compared right-ascending and left-descending colon tissue metabolomes to identify differences from the stool metabolome in normal weight, overweight, and obese adults. AIM:To examine right and left colon tissue metabolites according to body mass index that may serve as mechanistic targets for interventions and biomarkers for colon cancer risk. METHODS:Global, non-targeted metabolomics was applied to assess right-ascending and left-descending colon tissue collected from healthy adults undergoing screening colonoscopies to test the hypothesis that BMI differentially impacts colon tissue metabolite profiles. The colon tissue and stool metabolome of healthy adults (n = 24) was analyzed for metabolite signatures and metabolic pathway networks implicated in progression of colorectal cancer. RESULTS:Ascending and descending colon contained 504 host, food, and microbiota-derived metabolites from normal weight, overweight and obese adults grouped according to body mass index. Amino acids, lipids, and nucleotides were among the chemical types that further differentiated from the stool metabolite profiles. Normal weight adults had 46 significantly different metabolites between ascending and descending colon tissue locations, whereas there were 37 metabolite differences in overweight and 28 metabolite differences for obese adults (P < 0.05). Obese adults had trimethylamine N-oxide, endocannabinoids and monoacylglycerols with different relative abundances identified between ascending and descending colon. Primary and secondary bile acids, vitamins, and fatty acids also showed marked relative abundance differences in colon tissue from overweight/obese adults. CONCLUSION:There were metabolite profile differences between right-ascending and left-descending colon tissue in healthy adults. Colon lipids and other metabolites in obese and overweight adults were distinguished from normal weight participants and associated with gut inflammation, nutrient absorption, and products of microbiota metabolism.
Project description:Introduction and importanceThe spleen is normally found in the left hypochondrium and it is fixed in its place by numerous suspensory ligaments. When the ligaments are elongated or abnormally developed, it causes a rare medical condition called Wandering spleen. A persistent ascending and descending mesocolon is also a congenital anomaly, resulting from the failure of fusion of the primitive dorsal mesocolon.Case presentationHerein, a 5-year-old male child with sudden and acute onset of abdominal pain, constipation, nausea, tachycardia, and low urine output, imaging and blood tests revealed evidence of intestinal obstruction and normocytic anemia and neutrophilia. A laparotomy revealed persistent ascending and descending mesocolon, with a torsioned vascular pedicle of the spleen, resulting in splenomegaly and infarction. The surgeon successfully derotated the torsioned pedicle and performed a splenectomy. The patient had an uneventful postoperative course and was discharged without complications.Clinical discussionThis case could be asymptomatic and the diagnosis is incidental or it could be presented with ambiguous symptoms. The differential diagnosis of WS varies according to the clinical presentation and the associated complication. For instance, in the case of WS torsion and acute presentation, the differential diagnosis is ovarian torsion, acute appendicitis, and intestinal obstruction. Currently, surgery is the only suggested treatment option even in asymptomatic patients as well.ConclusionThis case of a Wandering Spleen is associated with a persistent ascending and descending mesocolon, suggesting that there may be certain risk factors. Therefore, we suggest making more research about wandering spleen in association with persistent mesocolon.
Project description:The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-ascending-descending action by the insect, which was highly reproducible and precisely corresponded to the changed expansion of the electric field. Other pole-climbing insects including the cigarette beetle (Lasioderma serricorne), which was shown to adopt the same behavior.