China
Africa
Explore chapters and articles related to this topic
Embryology of the Spinal Cord, Peripheral Nerves, and Vertebrae
Published in Bernard J. Dalens, Jean-Pierre Monnet, Yves Harmand, Pediatric Regional Anesthesia, 2019
Bernard J. Dalens, Jean-Pierre Monnet, Yves Harmand
In stage 9 (1.5- to 2-mm embryos, 19 to 20 d), the neural plate is curled (Figure 1.4). The embryonic disc elongates and the primitive streak and Hensen’s node appear to be carried caudad, since the cephalic area grows more rapidly. The embryo changes its shape, becoming first oval, then pear shaped. At this stage, the neural groove is in close contact with the notochord. Mesenchymatous cells of both sides of the notochord (paraxial mesoderm) show intense mitotic activity and differentiate as paired blocks of cells, the somites. This fundamental aspect of metamerism of the body does not occur in the paraxial mesoderm of the cephalic area.
The Abdominal Muscles
Published in Alan D. Miller, Armand L. Bianchi, Beverly P. Bishop, Neural Control of the Respiratory Muscles, 2019
During embryonic development the abdominal muscle fibers arise from several body segments or metameres.19 Each metamere receives one innervation band whose motor endplates form at the midpoints of the muscle fibers. Muscle fibers run in long parallel fascicles that span the distance from origin to aponeurosis of insertion, but single fibers extend only a fraction of the fascicle’s length. The muscle fibers are joined end-to-end either with or without an intervening tendon. As a consequence some muscle fibers lie in series and others lie in parallel. Thus, the contractile force or length changes generated by a motor unit or muscle may be unevenly distributed.
Formation of the Cranial Base and Craniofacial Joints
Published in D. Dixon Andrew, A.N. Hoyte David, Ronning Olli, Fundamentals of Craniofacial Growth, 2017
In the head region of vertebrates, the metameric pattern of paraxial mesoderm condensation is less well defined (Noden, 1982). Rostral to the first somite, the head mesoderm forms seven incompletely segregated condensations called somitomeres (Meier, 1979, 1981; Anderson and Meier, 1981; Meier and Jacobson, 1982). These are unique in that neither do they completely separate from one another nor do they differentiate into identifiable sclerotomes and dermatomal segments. They represent the most cephalic mesodermal contribution from the primitive streak, and it is onto this cranial modification of the paraxial mesoderm that cephalic neural crest cells migrate (Noden, 1982).
Ethical questions arising from Otfrid Foerster’s use of the Sherrington method to map human dermatomes
Published in Journal of the History of the Neurosciences, 2022
Brian Freeman, John Carmody, Damian Grace
At the 18th annual meeting of the German Society of Neurologists in Hamburg, Foerster presented further details on vasodilatation dermatomes, comparing some with the corresponding tactile dermatomes but without details of how either were plotted (Foerster 1928). He wrote that “the effect on irritation of a posterior root has a markedly metameric limitation, the zone of vasodilation corresponding to the skin dermatome in question.” This was Foerster’s first paper illustrating boundaries for 13 such dermatomes inscribed on photographs of patients.11Photographs show vasodilatation dermatomes for C3, C4, C5, C8, T2, T3, T4, T5, T7, T8, T10, T11, and L3. In most cases, the medical history and condition of the patient were not stated, nor was the interval between dorsal rhizotomy and photography. The rationale for dorsal rhizotomy around this time was stated by the American neurosurgeon Leo Max Davidoff (1898–1975), who met Foerster in Breslau in March 1927, commenting, “whenever he [Foerster] was faced by a patient with incurable pain he tried to give relief by directing a surgical colleague to cut the sensory roots in the involved area” (Davidoff 1928).
Quantitative proteomic analysis of venom from Southern India common krait (Bungarus caeruleus) and identification of poorly immunogenic toxins by immune-profiling against commercial antivenom
Published in Expert Review of Proteomics, 2019
Aparup Patra, Abhishek Chanda, Ashis K. Mukherjee
The SDS-PAGE analysis of SI B. caeruleus venom under reduced conditions separated the venom proteins into 17 sections with molecular masses ranging from 6 to 150 kDa (Figure1). The pattern of migration of the SI B. caeruleus venom proteins in the SDS-PAGE non-reduced conditions was different from the reduced conditions due to the occurrence of metameric proteins, self-aggregation of proteins, and/or interactions among the SI B. caeruleus venom proteins (Figure 1) [20,46,47]. The densitometry analyses of the SDS-PAGE bands (reduced) showed a predominance of SI B. caeruleus venom proteins (>85%) in the 5–15 kDa range (Figure1). Snake venom proteins in this molecular weight range are generally represented by PLA2, 3FTxs, and Kunitz-type serine protease inhibitors (KSPI), which suggests that the SI B. caeruleus venom (wild-type) is also enriched in these toxins, as corroborated by earlier reports [14,15].
Hypoesthesia in generalised anxiety disorder and major depression disorder
Published in International Journal of Psychiatry in Clinical Practice, 2018
Ana García-Blanco, Pablo González-Valls, Carmen Iranzo-Tatay, Luis Rojo-Moreno, Pilar Sierra, Lorenzo Livianos
The thalamus is the neuroanatomical region in which this hypoesthesia resides (López-Ibor, 1950; Rojo-Sierra, 1980). Moreover, thalamic abnormalities have been more related to MDD than to GAD (Bora, Harrison, Davey, Yücel, & Pantelis, 2012). Therefore, the hypoesthesia origin resides in localised functional alterations in central structures such as the thalamus. Hence, its corporal distribution corresponds with the distribution of thalamic anesthetics and it is not metameric (López-Ibor, 1950). Indeed, many thalamic disorders, which are usually accompanied by affective disorders, produce hypoesthesia localised on the malleolar regions of the foot (Greicius et al., 2007; Smith et al., 2003). For instance, while neuroimaging studies have found significant structural and functional anomalies located in the thalamus in MDD patients (Greicius et al., 2007), only neurochemical markers in a specific area of thalamus (i.e., choline in medial but not lateral thalamus) have been found in a subtype of anxiety disorder (obsessive compulsive disorder) (Smith et al., 2003).