scholarly journals Complete Unilateral Absence of Trapezius Muscle

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohammed Allouh ◽  
Adel Mohamed ◽  
Azedean Mhanni

Congenital partial absence of the trapezius muscle is a relatively common variation. Several cases of partial absence of the trapezius muscle have been reported. However, complete unilateral agenesis of this muscle has not been previously reported. In our case, a complete cadaver dissection of an 87-year-caucasian male was performed at the Department of Anatomy, College of Medicine in Saskatoon, Canada. The entire body dissection revealed a complete agenesis of the left trapezius muscle fibers. No other significant congenital anomalies were found.

2020 ◽  
Vol 21 (7) ◽  
pp. 2306
Author(s):  
Yong-Hee Han ◽  
Kyoung-Bin Ryu ◽  
Brenda I. Medina Jiménez ◽  
Jung Kim ◽  
Hae-Youn Lee ◽  
...  

Echiura is one of the most intriguing major subgroups of phylum Annelida because, unlike most other annelids, echiuran adults lack metameric body segmentation. Urechis unicinctus lives in U-shape burrows of soft sediments. Little is known about the molecular mechanisms underlying the development of U. unicinctus. Herein, we overviewed the developmental process from zygote to juvenile U. unicinctus using immunohistochemistry and F-actin staining for the nervous and muscular systems, respectively. Through F-actin staining, we found that muscle fibers began to form in the trochophore phase and that muscles for feeding were produced first. Subsequently, in the segmentation larval stage, the transversal muscle was formed in the shape of a ring in an anterior-to-posterior direction with segment formation, as well as a ventromedian muscle for the formation of a ventral nerve cord. After that, many muscle fibers were produced along the entire body and formed the worm-shaped larva. Finally, we investigated the spatiotemporal expression of Uun_st-mhc, Uun_troponin I, Uun_calponin, and Uun_twist genes found in U. unicinctus. During embryonic development, the striated and smooth muscle genes were co-expressed in the same region. However, the adult body wall muscles showed differential gene expression of each muscle layer. The results of this study will provide the basis for the understanding of muscle differentiation in Echiura.


2011 ◽  
Vol 29 (1) ◽  
pp. 299-303 ◽  
Author(s):  
H Rodriguez ◽  
O Espinoza-Navarro ◽  
I Silva ◽  
P Quiroz ◽  
C Arriaza ◽  
...  

Author(s):  
F. G. Zaki

Choline-deficiency was induced in Holtzman young rats of both sexes by feeding them a high fat - low protein diet.Preliminary studies of the ultrastructural changes in the myocardium of these animals have been recently reported from this laboratory. Myocardial lesions first appeared in the form of intraventricular mural thrombi, loss of cross striation of muscle fibers and focal necrosis of muscle cells associated with interstitial myocarditis. Prolonged choline-deficiency induced cardiomegaly associated with pericardial edema.During the early phase of this nutritional disorder, heart mitochondria - despite of not showing any swelling similar to that usually encountered in liver mitochondria of the same animal - ware the most ubiquitous site of marked structural abnormalities. Early changes in mitochondria appeared as vacuolation, disorganization, disruption and loss of cristae. Degenerating mitochondria were often seen quite enlarged and their matrix was replaced by whorls of myelin figures resembling lysosomal structures especially where muscle fibers were undergoing necrosis. In some areas, mitochondria appeared to be unusually clumped together where some contained membranelined vacuoles and others enclosed dense bodies and granular inclusions.


Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).


1986 ◽  
Vol 13 (2) ◽  
pp. 175-189
Author(s):  
Vincent R. Hentz
Keyword(s):  

ENTOMON ◽  
2020 ◽  
Vol 44 (4) ◽  
pp. 241-248
Author(s):  
P. Maheswara Reddy ◽  
M. Shankara Murthy

The specimens collected and reared to an adult stage on their respective hosts utilized to characterize the species of the genus Glyphodes based on morphological and genital characters of adults, revealed three species of the genus Glyphodes and were documented from Karnataka viz., Glyphodes caesalis Walker, Glyphodes pulverulentalis Hampson and Glyphodes vertumnalis Guenee on jack-fruit, mulberry and jasmine, respectively. These three species differ morphologically in having entire body green colour in G. vertumnalis, abdomen with oblique lateral stripes in G. pulverulentalis wherein, G. caesalis having sub-marginal black edged patch on costa with four spots. In genitalia, uncus greatly curved and beak shaped in G. vertumnalis, uncus slim and slightly curved in G. caesalis, whereas in G. pulverulentalis uncus long, narrow and slightly curved with short setae at apex.


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