Population Genomics of Nymphon australe Hodgson, 1902 (Pycnogonida, Nymphonidae) in the Western Antarctic

Within the Southern Ocean, the Antarctic Circumpolar Current is hypothesized to facilitate a circumpolar distribution for many taxa, even though some, such as pycnogonids, are assumed to have limited ability to disperse, based on brooding life histories and adult ambulatory capabilities. With a number of contradictions to circumpolarity reported in the literature for other pycnogonids, alternative hypotheses have been explored, particularly for Nymphon australe, the most common species of Pycnogonida (sea spider) in the Southern Ocean. Glacial events have been hypothesized to impact the capacity of organisms to colonize suitable areas without ice coverage as refuge and without the eurybathic capacity to colonize deeper areas. In this study, we examine populations of one presumed circumpolar species, the pycnogonid N. australe, from throughout the Western Antarctic, using a 2b-RAD approach to detect genetic variation with single-nucleotide polymorphisms. Using this approach, we found that N. australe included two distinct groups from within >5000-km sampling region. By using a discriminant analysis of principle components, sparse nonnegative matrix factorization, and admixture coefficient analysis, two distinctive populations were revealed in the Western Antarctic: one covered distances greater than 5000 km (Weddell, Western Antarctic Peninsula, and Ross Sea), and the other shared limited connectivity entrained within the Amundsen Sea. Under further scrutiny of the 3086 single-nucleotide polymorphisms in the data set, only 78 loci had alignment stacks between the two populations. We propose that the populations analyzed are divergent enough to constitute two different species from within this common Antarctic genus known for its phenotypic plasticity.

Current predictive models do not accurately differentiate between single and multi gland disease in primary hyperparathyroidism: a retrospective cohort study of two endocrine surgery units

Background Minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism is dependent upon accurate prediction of single-gland disease on the basis of preoperative imaging and biochemistry. The aims of this study were to validate currently available predictive models of single-gland disease in two UK cohorts and to determine if these models can facilitate MIP. Methods This is a retrospectively cohort study of 624 patients who underwent parathyroidectomy for primary hyperparathyroidism in two centres between July 2008 and December 2013. Two recognised models: CaPTHUS (preoperative calcium, parathyroid hormone, ultrasound, sestamibi, concordance imaging) and Wisconsin Index (preoperative calcium, parathyroid hormone) were validated for their ability to predict single-gland disease. Results The rates of single- and multi-gland disease were 491 (79.6%) and 126 (20.2%), respectively. Cure rates in centres 1 and 2 were 93.2% and 93.8%, respectively (P = 0.789). The positive predictive value (PPV) of CaPTHUS score . 3 in predicting single-gland disease was 84.6%, compared with 100% in the original report. CaPTHUS . 4 and 5 had a PPV of 85.1 and 87.1, respectively. There were no differences in Wisconsin Index (WIN) between patients with single- and multi-gland (P = 0.573). A WIN greater than 1600 and weight of excised gland greater than 1 g had a positive predictive value of 86.7% for single-gland disease. Conclusions The use of CaPTHUS and WIN indices without intraoperative adjuncts (such as IOPTH) had the potential to result in failure to cure in up to 15% (CaPTHUS) and 13% (WIN) of patients treated by MIP targeting a single enlarged gland.

Colorectal surgeons and biomedical scientists improve lymph node harvest in colorectal cancer

BACKGROUND

The aim of this study was to review lymph node retrieval from colorectal cancer resections.

METHODS

We examined consecutive, single colorectal cancers excised between September 1999 and February 2007. Data gathered included patient age and gender, cancer location, total number of lymph nodes and involved lymph nodes identified. The speciality of the operating surgeon was recorded. Whether a pathologist or biomedical scientist was responsible for harvesting lymph nodes from the resected specimen was also noted.

RESULTS

A total of 1,194 patients were identified. Increased numbers of lymph nodes identified was associated with increased lymph node positivity (p<0.001, r=0.121). Biomedical scientists identified more lymph nodes (median 15, range 12-20) within specimens than consultant pathologists (median 10, range 7-13; p<0.001). Colorectal surgeons removed more lymph nodes (median 11, range 7-15) than non-colorectal surgeons (median 9, range 7-14; p=0.002).

CONCLUSIONS

There was a significant increase in lymph node harvesting over time and this correlated with lymph node positivity. Lymph node harvest was significantly higher when the resection was performed by a colorectal surgeon and when the specimen was examined by a biomedical scientist. For accurate staging and consequent correct planning of adjuvant treatment and prognosis, resections should be performed by a colorectal surgeon and the lymph nodes harvested by a biomedical scientist.

A review of chronic anal fissure management

Anal fissure management has rapidly progressed in the last 15 years as our understanding of fissure pathophysiology has developed. All methods of treatment aim to reduce the anal sphincter spasm associated with chronic anal fissures. Surgical techniques have been used for over 100 years with success. Lateral internal sphincterotomy remains the surgical treatment of choice for many practitioners. Postoperative impairment of continence remains controversial. Recently, less invasive methods of treatment have been explored. Topical nitrates, calcium channel blockers and botulinum toxin are established treatments. These and other non-surgical treatments are described in this review. Various guidelines and treatment algorithms for anal fissure are also discussed.

Attitudes of young adults to prenatal screening and genetic correction for human attributes and psychiatric conditions

With recent advances in DNA technology, questions have arisen as to how this technology should be appropriately used. In this article, results obtained from a survey designed to elicit attitudes of college students to prenatal testing and gene therapy for human attributes and psychiatric conditions are reported. The eleven hypothetical disease phenotypes included schizophrenia, alcoholism, tendency toward violent behavior, attention deficit/hyperactivity disorder, depression requiring medical treatment, obesity, involvement in "dangerous" sports activities, homosexuality, borderline normal IQ (80-100), proportional short stature, and inability to detect perfect pitch. Most students supported prenatal genetic testing for psychiatric disorders and behavior that might result in harm to others (i.e., tendency towards violent behavior) and found prenatal genetic testing for human attributes less desirable. However, the lack of unilateral agreement or disagreement toward any one condition or attribute suggests the potential difficulties ahead in the quest for guidelines for the application of new technologies available to manipulate the human genome.

FISH localization of the soluble thymidine kinase gene (TK1) to human 17q25, a region of chromosomal loss in sporadic breast tumors

Soluble thymidine kinase (TK1) is an important 17q marker in somatic cell genetics. Its activity is increased in many malignancies, including breast cancer. Through somatic cell hybrid and fluorescence in situ hybridization studies, we mapped TK1 to 17q25.2-->25.3, in region demonstrating loss of heterozygosity in primary breast tumors. It lies near D17S836 and is proximal to the avian erythroblastic leukemia viral oncogene homolog 2-like gene (ERBA2L).