A study of anatomical variability of the omohyoid muscle and its clinical relevance

OBJECTIVE: The omohyoid muscle is a long, thin muscle consisting of superior and inferior bellies and an intermediate tendon, which runs obliquely in the lateral cervical region. The omohyoid is important in neck dissections because it is the surgical landmark for level III and IV lymph node metastases. METHODS: In the present study, the anterior and posterior triangle of the neck was dissected in 35 male cadavers and observed for variations in the omohyoid bilaterally. Observations were focused on variations in number, attachments, and position of omohyoid. RESULTS: Among the 35 cadavers studied, double omohyoid was present in one cadaver, inferior belly originated from the clavicle in three cadavers, superior belly merged with the sternohyoid in two cadavers, and the omohyoid received additional slips from the sternum in one cadaver. Standard attachment and position of the omohyoid was observed in the remaining cadavers. CONCLUSION: Variations of this muscle are important because of its close relation to the large vessels and brachial plexus. Because of the direct adhesion of the intermediate tendon to the anterior wall of the internal jugular vein and its connection with it through a thin lamina of the pretracheal layer of the cervical fascia, the contraction of the omohyoid muscle has a direct effect on the lumen of this vessel

Anatomical Variation of Radial Wrist Extensor Muscles: A Study in Cadavers

OBJECTIVE: The tendons of the extensor carpi radialis longus and brevis muscles are quite useful in tendon transfer, such as in correction of finger clawing and restoration of thumb opposition. Knowledge of additional radial wrist extensor muscle bellies with independent tendons is useful in the above-mentioned surgical procedures. METHODS: The skin, subcutaneous tissue, and antebrachial fascia of 48 (24 on the right side and 24 on left side) male upper limb forearms were dissected. The following aspects were then analyzed: (a) the presence of additional muscle bellies of radial wrist extensors, (b) the origin and insertion of the additional muscle, and (c) measurements of the muscle bellies and their tendons. RESULTS: Five out of 48 upper limbs (10.41%) had additional radial wrist extensors; this occurred in 3 out of 24 left upper limbs (12.5%) and 2 out of 24 right upper limbs (8.3%). In one of the right upper limbs, two additional muscles were found. The length and width of each additional muscle belly and its tendon ranged between 2 - 15cm by 0.35 - 6.4cm and 2.8 - 20.8cm by 0.2 0.5cm, respectively. The additional radial wrist extensor tendons in our study basically originated either from the extensor carpi radialis longus or brevis muscles and were inserted at the base of the 2nd or 3rd metacarpal bone. CONCLUSION: The present study will inform surgeons about the different varieties of additional radial wrist extensors and the frequency of their occurrence

Entrapment of the Martin-Gruber branch of median nerve in the forearm

We report a rare case of a dual neuro-vascular variation, which was observed in the right extremity of male cadaver. About an inch inferior to the elbow joint, three branches arose from the median nerve. These were the anterior interosseous branch, a Martin-Gruber branch (MGB) and a muscular branch. The MGB coursed infero-medially to join with the ulnar nerve by running posterior to the ulnar artery. It was surprising to observe that the MGB passed between the ulnar artery and its venae comitantes. There was an acute angulation of the MGB here, suggesting entrapment at this site

Atypical insertion of the abductor pollicis longus muscle, an anatomical case report

During a routine dissection of upper limb in the Department of Anatomy, we came across an unusual attachment of the abductor pollicis longus muscle. Proximal fleshy belly of it originated from the dorsal surface of the shaft of the radius as usual. As it descended it split into two tendons (lateral and medial) proximal to the wrist. The medial tendon attached to the lateral side of base of the first metacarpal bone, whereas the lateral tendon again converted into a fleshy belly at its distal part and inserted into the proximal phalanx of the thumb overlapping the insertion of the abductor pollicis brevis. Double tendons of abductor pollicis longus, each inserting separately into different sites is a rare incidence and needs to be reported to enhance the success rate of any surgical procedures at this region

A study of anatomical variability of the omohyoid muscle and its clinical relevance

OBJECTIVE: The omohyoid muscle is a long, thin muscle consisting of superior and inferior bellies and an intermediate tendon, which runs obliquely in the lateral cervical region. The omohyoid is important in neck dissections because it is the surgical landmark for level III and IV lymph node metastases. METHODS: In the present study, the anterior and posterior triangle of the neck was dissected in 35 male cadavers and observed for variations in the omohyoid bilaterally. Observations were focused on variations in number, attachments, and position of omohyoid. RESULTS: Among the 35 cadavers studied, double omohyoid was present in one cadaver, inferior belly originated from the clavicle in three cadavers, superior belly merged with the sternohyoid in two cadavers, and the omohyoid received additional slips from the sternum in one cadaver. Standard attachment and position of the omohyoid was observed in the remaining cadavers. CONCLUSION: Variations of this muscle are important because of its close relation to the large vessels and brachial plexus. Because of the direct adhesion of the intermediate tendon to the anterior wall of the internal jugular vein and its connection with it through a thin lamina of the pretracheal layer of the cervical fascia, the contraction of the omohyoid muscle has a direct effect on the lumen of this vessel

Estrogen-induced hypomethylation and overexpression of <i>YAP1 </i>facilitate breast cancer cell growth and survival

Increased expression of Yes-associated protein-1 (YAP1) was shown to correlate with reduced survival in breast cancer (BC) patients. However, the exact mechanism of YAP1 regulation in BC cells remains ambiguous. Genomic sequence search showed that the promoter region of the YAP1 gene contains CpG Islands, hence the likelihood of epigenetic regulation by DNA methylation. To address this possibility, the effect of estrogen (17β estradiol; E2) on YAP1 gene expression and YAP1 promoter methylation status was evaluated in BC cells. The functional consequences of E2 treatment in control and YAP1-silenced BC cells were also investigated. Our data showed that E2 modulates YAP1 expression by hypomethylation of its promoter region via downregulation of DNA methyltransferase 3B (DNMT3B); an effect that seems to facilitate tumor progression in BC cells. Although the effect of E2 on YAP1 expression was estrogen receptor (ER) dependent, E2 treatment also upregulated YAP1 expression in MDA-MB231 and SKBR3 cells, which are known ER-negative BC cell lines but expresses ERα. Functionally, E2 treatment resulted in increased cell proliferation, decreased apoptosis, cell cycle arrest, and autophagic flux in MCF7 cells. The knockdown of the YAP1 gene reversed these carcinogenic effects of E2 and inhibited E2-induced autophagy. Lastly, we showed that YAP1 is highly expressed and hypomethylated in human BC tissues and that increased YAP1 expression correlates negatively with DNMT3B expression but strongly associated with ER expression. Our data provide the basis for considering screening of YAP1 expression and its promoter methylation status in the diagnosis and prognosis of BC.</p

Emerging role of caldesmon in cancer: A potential biomarker for colorectal cancer and other cancers

Colorectal cancer (CRC) is a devastating disease, mainly because of metastasis. As a result, there is a need to better understand the molecular basis of invasion and metastasis and to identify new biomarkers and therapeutic targets to aid in managing these tumors. The actin cytoskeleton and actin-binding proteins are known to play an important role in the process of cancer metastasis because they control and execute essential steps in cell motility and contractility as well as cell division. Caldesmon (CaD) is an actin-binding protein encoded by the CALD1 gene as multiple transcripts that mainly encode two protein isoforms: High-molecular-weight CaD, expressed in smooth muscle, and low-molecular weight CaD (l-CaD), expressed in nonsmooth muscle cells. According to our comprehensive review of the literature, CaD, particularly l-CaD, plays a key role in the development, metastasis, and resistance to chemoradiotherapy in colorectal, breast, and urinary bladder cancers and gliomas, among other malignancies. CaD is involved in many aspects of the carcinogenic hallmarks, including epithelial mesenchymal transition via transforming growth factor-beta signaling, angiogenesis, resistance to hormonal therapy, and immune evasion. Recent data show that CaD is expressed in tumor cells as well as in stromal cells, such as cancerassociated fibroblasts, where it modulates the tumor microenvironment to favor the tumor. Interestingly, CaD undergoes selective tumor-specific splicing, and the resulting isoforms are generally not expressed in normal tissues, making these transcripts ideal targets for drug design. In this review, we will analyze these features of CaD with a focus on CRC and show how the currently available data qualify CaD as a potential candidate for targeted therapy in addition to its role in the diagnosis and prognosis of cancer

Autophagy related markers (Beclin-1 and ATG4B) are strongly expressed in Wilms' tumor and correlate with favorable histology

Background. Wilms’ tumor treatment has achieved great success in the last decade. Nevertheless, some cases still fail to respond to the current multimodality therapy. These cases fall mainly in the unfavorable histology group with very few belonging to the favorable histology group. In recent years, autophagy manipulation whether inhibition or stimulation has been shown to affect cancer cell behavior and has emerged as a novel mechanism to improve cancer cell response to currently used therapeutic regimens. Objective. The current study aimed to investigate the expression of autophagy related markers (ATG4B and Beclin1) in WT, its association with the different clinicpathological parameters and its impact on patient survival. Methods. Twenty-one formalin fixed paraffin embedded (FFPE) WT specimens were immunohistochemically stained using autophagy related markers; Beclin-1 and ATG4B. All clinical, radiological and follow up data were retrieved from the patient records. Results. All specimens showed positive expression of both Beclin-1 and ATG4B. The staining score for Beclin1 varied between 50 and 300, and its expression was significantly associated with favorable histology (p=0.007). Similarly, ATG4B expression was significantly higher in favorable histology tumors compared to unfavorable histology (p=0.046). A statistically significant positive correlation between Beclin-1 and ATG4B expression was observed. The cumulative disease-free survival in patients with favorable histology was significantly higher compared to patients with unfavorable histology (p=0.0027). Conclusions. Beclin-1 and ATG4B expression were both found to be statistically significant discriminators of survival. Collectively these findings suggest that the expression of autophagy-related markers is associated with a favorable histology and could predict better survival in these patients