Animal toxins: what features differentiate pore blockers from gate modifiers

A surprisingly large number of animal toxins target voltage sensitive ion channels. Even though there exists toxins for all four major voltage sensitive ion channels, a majority act either on sodium or potassium channels. Given a specific primary sequence, the challenge is to determine in an automated fashion whether a given substance is toxic, and what its site of action might be. Currently, there are signals such as functional dyads that are indicative of a toxin, but are not yet specific enough to allow accurate prediction of the site of action. In this paper, an automated approach for detecting whether a toxin acts on voltage-sensitive sodium versus potassium channels is presented. In addition, our consensus sequence is also able to reliably determine whether the toxin acts as a gate modifier or pore blocker (> 93% accuracy)

Effect of uncorrected astigmatism on vision

PURPOSE: To examine the effect of uncorrected astigmatism in older adults. SETTING: University Vision Clinic METHOD: Twenty-one healthy presbyopes, aged 58.9±2.8 years, had astigmatism of 0.0 to -4.0 x 90?DC and -3.0DC of cylinder at 90?, 180? and 45? induced with spectacle lenses, with the mean spherical equivalent compensated to plano, in random order. Visual acuity was assessed binocularly using a computerised test chart at 95%, 50% and 10% contrast. Near acuity and reading speed were measured using standardised reading texts. Light scatter was quantified with the cQuant and driving reaction times with a computer simulator. Finally visual clarity of a mobile phone and computer screen was subjectively rated. RESULTS: Distance visual acuity decreased with increasing uncorrected astigmatic power (F=174.50, p0.05), but the reliability and variability of measurements decreased with increasing uncorrected astigmatic power (p0.05), but subjective rating of clarity decreased with increasing uncorrected astigmatic power (p<0.001). Uncorrected astigmatism at 45? or 180? orientation resulted in a worse distance and near visual acuity, and subjective rated clarity than 90? orientation (p<0.05). CONCLUSION: Uncorrected astigmatism, even as low as 1.0DC, causes a significant burden on a patient’s vision. If left uncorrected, this could impact significantly on their independence, quality of life and wellbeing

Astigmatism and vision:should all astigmatism always be corrected?

As technology and medical devices improve, there is much interest in when and how astigmatism should be corrected with refractive surgery. Astigmatism can be corrected by most forms of refractive surgery, such as using excimer lasers algorithms to ablate the cornea to compensate for the magnitude of refractive error in different meridians. Correction of astigmatism at the time of cataract surgery is well developed and can be achieved through incision placement, relaxing incisions and toric intraocular lens (IOL) implantation. This was less of an issue in the past when there was a lower expectation to be spectacle independent after cataract surgery, in which case the residual refractive error, including astigmatism, could be compensated for with spectacle lenses. The issue of whether presurgical astigmatism should be corrected can be considered separately depending on whether a patient has residual accommodation, and the type of refractive surgery under consideration. We have previously reported on the visual impact of full correction of astigmatism, rather than just correcting the mean spherical equivalent. Correction of astigmatism as low as 1.00 dioptres significantly improves objective and subjective measures of functional vision in prepresbyopes at distance and near

Radical resection of large metastatic non-functioning pancreatic neuroendocrine carcinoma complicated by splenic vein thrombosis and sinistral portal hypertension.

INTRODUCTION AND IMPORTANCE: There are limited reports in the literature of radical surgical resection for pancreatic neuroendocrine carcinoma (PNEC). In patients with non-functioning PNEC (NF-PNEC) within the tail of the pancreas tumours can cause splenic vein thrombosis (SVT) and subsequent sinitral portal hypertension (SPH). Radical surgical resection in such patients with concomitant liver metastasis has not previously been reported. CASE PRESENTATION: We present a 67-year old female patient who presented with a large NF-PNEC within the tail of the pancreas with liver metastasis. We performed a distal pancreatectomy, splenectomy, partial gastrectomy and liver resection to achieve radical resecton. DISCUSSION: All patients with NF-PNEC within the tail of the pancreatic should be considered for radical surgical resection. In the presence of multi-visceral involvement and complications such as SVT and/or SPH multi-speciality surgical expertise is likely to be required. CONCLUSION: Radical multi-visceral resection for large NF-PNEC can be safely performed in the presence of SVT and SPH

‘The Home Beyond Home’: Dr. Balbinder S. Bhogal in conversation with Dr. Sunny Dhillon

This piece is a lightly edited transcript of an interview with Dr. Bhogal conducted by Sunny in late 2022 in Nottingham, UK. Key themes that emerge concern the untranslatable aspects of ‘religion’ (Derrida, 2002), finding a spiritual home, negotiating the dialectic between bodily wisdom and linguistic expression, as well as how to possibly lead a life of integrity in the face of myriad challenges

The consideration of heart rate complexity as a co-morbidity factor for liver transplantation selection procedures

The recent article published covering "The role of autonomic dysfunction in predicting 1-year mortality after liver transplantation" (1) provides some useful insight into post-transplantation survival. However, it seems to us that the data lend themselves to a different interpretation, possibly pointing to a new application of heart rate variability analysis in patients awaiting liver transplantation

Medical image encryption using chaotic map improved advanced encryption standard

Under the Digital Image and Communication in Medicine (DICOM) standard, the Advanced Encryption Standard (AES) is used to encrypt medical image pixel data. This highly sensitive data needs to be transmitted securely over networks to prevent data modification. Therefore, there is ongoing research into how well encryption algorithms perform on medical images and whether they can be improved. In this paper, we have developed an algorithm using a chaotic map combined with AES and tested it against AES in its standard form. This comparison allowed us to analyse how the chaotic map affected the encryption quality. The developed algorithm, CAT-AES, iterates through Arnold’s cat map before encryption a certain number of times whereas, the standard AES encryption does not. Both algorithms were tested on two sets of 16-bit DICOM images: 20 brain MRI and 26 breast cancer MRI scans, using correlation coefficient and histogram uniformity for evaluation. The results showed improvements in the encryption quality. When encrypting the images with CAT-AES, the histograms were more uniform, and the absolute correlation coefficient was closer to zero for the majority of images tested on

Development of antigen-specific ELISA for circulating autoantibodies to extracellular matrix protein 1 in lichen sclerosus

Lichen sclerosus is a common, acquired chronic inflammatory skin disease of unknown etiology, although circulating autoantibodies to the glycoprotein extracellular matrix protein 1 (ECM1) have been detected in most patients’ sera. We have examined the nature of ECM1 epitopes in lichen sclerosus sera, developed an ELISA system for serologic diagnosis, and assessed clinicopathological correlation between ELISA titer and disease. Epitope-mapping studies revealed that lichen sclerosus sera most frequently recognized the distal second tandem repeat domain and carboxyl-terminus of ECM1. We analyzed serum autoantibody reactivity against this immunodominant epitope in 413 individuals (95 subjects with lichen sclerosus, 161 normal control subjects, and 157 subjects with other autoimmune basement membrane or sclerosing diseases). The ELISA assay was highly sensitive; 76 of 95 lichen sclerosus patients (80.0%) exhibited IgG reactivity. It was also highly specific (93.7%) in discriminating between lichen sclerosus and other disease/control sera. Higher anti-ECM1 titers also correlated with more longstanding and refractory disease and cases complicated by squamous cell carcinoma. Furthermore, passive transfer of affinity-purified patient IgG reproduced some histologic and immunopathologic features of lichen sclerosus skin. This new ELISA is valuable for the accurate detection and quantification of anti-ECM1 autoantibodies. Moreover, the values may have clinical significance in patients with lichen sclerosus

Multifocal intraocular lens differentiation using defocus curves

Purpose: To determine the most appropriate analysis technique for the differentiation of multifocal intraocular lens (MIOL) designs using defocus curve assessment of visual capability.Methods:Four groups of fifteen subjects were implanted bilaterally with either monofocal intraocular lenses, refractive MIOLs, diffractive MIOLs, or a combination of refractive and diffractive MIOLs. Defocus curves between -5.0D and +1.5D were evaluated using an absolute and relative depth-of-focus method, the direct comparison method and a new 'Area-of-focus' metric. The results were correlated with a subjective perception of near and intermediate vision. Results:Neither depth-of-focus method of analysis were sensitive enough to differentiate between MIOL groups (p>0.05). The direct comparison method indicated that the refractive MIOL group performed better at +1.00, -1.00 and -1.50 D and worse at -3.00, -3.50, -4.00 and -5.00D compared to the diffractive MIOL group (