Bilateral carotid body and cervical sympathetic chain paragangliomas: A case report and review of the literature

Background: Paragangliomas are rare neuroendocrine tumors which develop at the site of extra-adrenal paraganglia of the autonomic nervous system, originating in the neural crest. Case presentation: We report the extremely rare finding of 4 concurrent paragangliomas arising bilaterally and simultaneously involving the carotid bodies and superior cervical ganglia of the sympathetic trunk in a 53-year-old man. These tumors were large enough to cause unilateral sympathetic chain dysfunction resulting in Horner's syndrome, in addition to oropharyngeal compression causing obstructive sleep apnea. The patient's clinical course, surgical treatment, and management considerations are discussed here. Conclusion: The morbidity associated with Horner's syndrome is relatively low; therefore, resection of these tumors is less controversial. However, the surgical access to large masses in the parapharyngeal space is more difficult and, in some cases, requires mandibulotomy to ensure that critical neurovascular structures are preserved during the resection. Keywords: Paraganglioma, Parapharyngeal space, Cervical sympathetic chain, Carotid body tumor, Horner's syndrom

Septic arthritis of the sternoclavicular joint: A unique late complication after tracheostomy

BACKGROUND: Septic arthritis of the sternoclavicular joint is a rare infection associated with significant morbidity and mortality. Several risk factors for septic arthritis have been reported in the literature ranging from immunodeficiency to intravenous drug use. CASE PRESENTATION: A 63-year-old male previously treated for synchronous squamous cell carcinomas of the epiglottis and floor of mouth presented with tenderness and swelling of the sternoclavicular joint two months after tracheostomy decannulation. Computed tomography and bone scans confirmed the diagnosis of septic arthritis of the sternoclavicular joint. The patient\u27s clinical course, surgical treatment, and management considerations are discussed here. CONCLUSION: Septic arthritis of the SCJ is a rare but serious infection. Once diagnosed, septic arthritis of the SCJ should be promptly treated to prevent further morbidity and mortality

Aberrant course of the dominant superior thyroid artery in a patient undergoing a total thyroidectomy

We present the case of a 38-year-old Caucasian female who underwent a total thyroidectomy for papillary thyroid carcinoma. We identified a large anomalous superior thyroid artery (STA) that emerged as a second branch of the external carotid artery and entered the thyroid isthmus superficial to the right sternothyroid muscle. In this case report, we discuss the embryology of the thyroid gland as well as the possible embryological basis for this unusual course of the STA. In doing so, we aim to improve recognition of the potential vascular variations in the thyroid gland, in turn aiding surgeons in the prevention of unnecessary complications and providing insight into the embryologic development of this organ

Genome-wide association for testis weight in the diversity outbred mouse population.

Testis weight is a genetically mediated trait associated with reproductive efficiency across numerous species. We sought to evaluate the genetically diverse, highly recombinant Diversity Outbred (DO) mouse population as a tool to identify and map quantitative trait loci (QTLs) associated with testis weight. Testis weights were recorded for 502 male DO mice and the mice were genotyped on the GIGAMuga array at ~ 143,000 SNPs. We performed a genome-wide association analysis and identified one significant and two suggestive QTLs associated with testis weight. Using bioinformatic approaches, we developed a list of candidate genes and identified those with known roles in testicular size and development. Candidates of particular interest include the RNA demethylase gene Alkbh5, the cyclin-dependent kinase inhibitor gene Cdkn2c, the dynein axonemal heavy chain gene Dnah11, the phospholipase D gene Pld6, the trans-acting transcription factor gene Sp4, and the spermatogenesis-associated gene Spata6, each of which has a human ortholog. Our results demonstrate the utility of DO mice in high-resolution genetic mapping of complex traits, enabling us to identify developmentally important genes in adult mice. Understanding how genetic variation in these genes influence testis weight could aid in the understanding of mechanisms of mammalian reproductive function

Genome-wide association mapping of ethanol sensitivity in the Diversity Outbred mouse population.

BACKGROUND: A strong predictor for the development of alcohol use disorder (AUD) is altered sensitivity to the intoxicating effects of alcohol. Individual differences in the initial sensitivity to alcohol are controlled in part by genetic factors. Mice offer a powerful tool to elucidate the genetic basis of behavioral and physiological traits relevant to AUD, but conventional experimental crosses have only been able to identify large chromosomal regions rather than specific genes. Genetically diverse, highly recombinant mouse populations make it possible to observe a wider range of phenotypic variation, offer greater mapping precision, and thus increase the potential for efficient gene identification. METHODS: We have taken advantage of the Diversity Outbred (DO) mouse population to identify and precisely map quantitative trait loci (QTL) associated with ethanol sensitivity. We phenotyped 798 male J:DO mice for three measures of ethanol sensitivity: ataxia, hypothermia, and loss of the righting response. We used high-density MegaMUGA and GigaMUGA to obtain genotypes ranging from 77,808 to 143,259 SNPs. We also performed RNA sequencing in striatum to map expression QTLs and identify gene expression-trait correlations. We then applied a systems genetic strategy to identify narrow QTLs and construct the network of correlations that exists between DNA sequence, gene expression values, and ethanol-related phenotypes to prioritize our list of positional candidate genes. RESULTS: We observed large amounts of phenotypic variation with the DO population and identified suggestive and significant QTLs associated with ethanol sensitivity on chromosomes 1, 2, and 16. The implicated regions were narrow (4.5-6.9 Mb in size) and each QTL explained ~4-5% of the variance. CONCLUSIONS: Our results can be used to identify alleles that contribute to AUD in humans, elucidate causative biological mechanisms, or assist in the development of novel therapeutic interventions