Structural insight into selectivity of amylin and calcitonin receptor agonists

Amylin receptors (AMYRs), heterodimers of the calcitonin receptor (CTR) and one of three receptor activity-modifying proteins, are promising obesity targets. A hallmark of AMYR activation by Amy is the formation of a 'bypass' secondary structural motif (residues S19-P25). This study explored potential tuning of peptide selectivity through modification to residues 19-22, resulting in a selective AMYR agonist, San385, as well as nonselective dual amylin and calcitonin receptor agonists (DACRAs), with San45 being an exemplar. We determined the structure and dynamics of San385-bound AMY3R, and San45 bound to AMY3R or CTR. San45, via its conjugated lipid at position 21, was anchored at the edge of the receptor bundle, enabling a stable, alternative binding mode when bound to the CTR, in addition to the bypass mode of binding to AMY3R. Targeted lipid modification may provide a single intervention strategy for design of long-acting, nonselective, Amy-based DACRAs with potential anti-obesity effects.

Characterization of cephalic and non-cephalic sensory cell types provides insight into joint photo- and mechanoreceptor evolution

Rhabdomeric opsins (r-opsins) are light sensors in cephalic eye photoreceptors, but also function in additional sensory organs. This has prompted questions on the evolutionary relationship of these cell types, and if ancient r-opsins were non-photosensory. A molecular profiling approach in the marine bristleworm Platynereis dumerilii revealed shared and distinct features of cephalic and non-cephalic r-opsin1-expressing cells. Non-cephalic cells possess a full set of phototransduction components, but also a mechanosensory signature. Prompted by the latter, we investigated Platynereis putative mechanotransducer and found that nompc and pkd2.1 co-expressed with r-opsin1 in TRE cells by HCR RNA-FISH. To further assess the role of r-Opsin1 in these cells, we studied its signaling properties and unraveled that r-Opsin1 is a Gαq-coupled blue light receptor. Profiling of cells from r-opsin1 mutants versus wild-types, and a comparison under different light conditions reveals that in the non-cephalic cells light - mediated by r-Opsin1 - adjusts the expression level of a calcium transporter relevant for auditory mechanosensation in vertebrates. We establish a deep-learning-based quantitative behavioral analysis for animal trunk movements and identify a light- and r-Opsin-1-dependent fine-tuning of the worm's undulatory movements in headless trunks, which are known to require mechanosensory feedback. Our results provide new data on peripheral cell types of likely light sensory/mechanosensory nature. These results point towards a concept in which such a multisensory cell type evolved to allow for fine-tuning of mechanosensation by light. This implies that light-independent mechanosensory roles of r-opsins may have evolved secondarily.

Trends in the quality of work presented at the society of british neurological surgeons meetings: 1975 to 2010

BACKGROUND

The quality of scientific publications in clinical journals is well studied but the quality of work presented at medical conferences less so.

AIMS

To describe trends in the quality of presentations at the Society of British Neurological Surgeons [SBNS] conference between 1975 and 2010 and the factors associated with higher quality work in order to consider what might improve publication rates.

METHODS

Analysis was conducted in 5-year time periods (i.e. 1975-1979, 1985-1989, 1995-1999, 2005-2009). Published abstracts were used to identify conference presentations. Quality metrics included level of evidence of the presentation and eventual publication within 5 years. Publication 5-year citation count and destination journal impact factor were further used to assess publication quality. Statistical analysis was carried out using SPSS.

RESULTS

Of the 1711 presentations in total, 479 (28%) were published. The British Journal of Neurosurgery (93, 19%) was the favoured destination. Although the total number of publications has increased, given the increase in the number of presentations, the proportion of work published has decreased (80/179; 45% in the 1970s to 113/721; 16% in the 2000s). The growth in the impact factor of published work was better than that found in leading neurosurgical journals, but lower than for leading medical journals. In a multivariate model, presentations using a higher level of evidence increased the likelihood of publication (AOR 6.7 95% CI 3.7, 12.1), whilst presenting at conferences after the 1970s reduced the likelihood of publication; 1985-1989 (AOR 0.3, 95% CI 0.2, 0.4), 1995-1999 (0.4, 95% CI 0.3, 0.7) and 2005-2009 (0.1, 95% CI 0.1, 0.2).

CONCLUSION

SBNS conferences today contain more presentations and yield more publications than ever before. However, the increased volume may dilute the quality of work presented.

Metastatic small cell carcinoma to the testis

Testicular neoplasms comprise 1% of all malignancies in men, with less than 3% of these malignancies due to metastatic disease. We report a case of a 51-year-old man with a history of left pneumonectomy done 2 years earlier for small cell carcinoma of the lung; the patient came to his primary care physician for routine follow-up. Physical examination was significant for a left testicular mass, which on final pathology was diagnosed as metastatic small cell carcinoma.

Metastatic adenocarcinoma of the pancreas to the testicle: a case report

We report a 58-year-old man who presented with a 1-month history of left testicular pain and swelling that was eventually diagnosed as metastatic adenocarcinoma from the pancreas. Currently, there are only three accounts in the English literature of metastatic pancreatic carcinoma to the testis.

The accident department and Age Concern

Accident and Emergency Departments are increasingly becoming major providers of primary health care to the elderly. The attendance of an elderly person at an Accident Department may be associated with loss of independence and this may lead to admission to hospital. Such admissions, may sometimes, be avoided by the provision of immediate social support in the community. For five years, we have worked with the Age Concern after-care officer who is able to provide such assistance by liaison with the Social Services. To provide longer-term help, she works closely with the community-based Age Concern network. The Community and Social Services, as well as the Hospital-based services, have benefited from her presence.