Beam combining using Orientational Stimulated Scattering in Liquid Crystals

Possibility of beam combining and clean-up using Orientational Stimulated Scattering in a Nematic Liquid Crystal is considered. We numerically study the dynamics of the process and find that back-conversion process tends to limit the effective interaction strength. Instability of the steady state of cross-phase modulation is demonstrated, when both waves have the same frequency. We show that high conversion efficiency can be achieved, and that the shape and wave-front of the amplified output signal are robust with respect to amplitude and phase distortions of the input pump.Comment: 24 pages, 6 figures, will be published in JOSA

Antisense oligonucleotide-induced alternative splicing of the APOB mRNA generates a novel isoform of APOB

BACKGROUND: Apolipoprotein B (APOB) is an integral part of the LDL, VLDL, IDL, Lp(a) and chylomicron lipoprotein particles. The APOB pre-mRNA consists of 29 constitutively-spliced exons. APOB exists as two natural isoforms: the full-length APOB100 isoform, assembled into LDL, VLDL, IDL and Lp(a) and secreted by the liver in humans; and the C-terminally truncated APOB48, assembled into chylomicrons and secreted by the intestine in humans. Down-regulation of APOB100 is a potential therapy to lower circulating LDL and cholesterol levels. RESULTS: We investigated the ability of 2'O-methyl RNA antisense oligonucleotides (ASOs) to induce the skipping of exon 27 in endogenous APOB mRNA in HepG2 cells. These ASOs are directed towards the 5' and 3' splice-sites of exon 27, the branch-point sequence (BPS) of intron 26–27 and several predicted exonic splicing enhancers within exon 27. ASOs targeting either the 5' or 3' splice-site, in combination with the BPS, are the most effective. The splicing of other alternatively spliced genes are not influenced by these ASOs, suggesting that the effects seen are not due to non-specific changes in alternative splicing. The skip 27 mRNA is translated into a truncated isoform, APOB87(SKIP27). CONCLUSION: The induction of APOB87(SKIP27 )expression in vivo should lead to decreased LDL and cholesterol levels, by analogy to patients with hypobetalipoproteinemia. As intestinal APOB mRNA editing and APOB48 expression rely on sequences within exon 26, exon 27 skipping should not affect APOB48 expression unlike other methods of down-regulating APOB100 expression which also down-regulate APOB48

Ockham’s Razor for a Retinal Lesion and Acromegaly and Breaking the Vicious Circle

Acromegaly due to ectopic secretion of growth hormone-releasing hormone (GHRH) is rare. Treatment consists of surgical removal of the primary tumor, cytostatic therapy, “cold” or radioactive somatostatin analogue treatment, and medical therapy for acromegaly, if needed. A 53 year-old female had an ocular lesion noted on a routine optician visit, originally considered to be an ocular melanoma. She had a bronchial carcinoid successfully removed 22 years previously. She had acromegalic features with an enlarged pituitary gland on magnetic resonance imaging and, additionally, metastatic lesions in her bones, liver, and thyroid gland. Elevated GHRH levels (>250× upper limit of normal) suggested a metastatic lung neuroendocrine tumor secreting GHRH. Cold and radioactive somatostatin analogue therapy reduced both GHRH and insulin-like growth factor 1 (IGF-1) levels, but normalization of the biochemical markers of acromegaly was only achieved after pegvisomant was introduced. Complete control of IGF-1 was achieved, and this may have hindered the growth of the metastatic lesions as well, as the patient remains well 13 years after the diagnosis of metastatic disease and 35 years after the original lung operation. A gradual rise in prolactin levels over last 4 years was noted, which is likely due to the prolonged effect of GHRH on prolactin-secreting cells. The diagnosis of this case applied the law of parsimony from the Ockham’s razor principle. We consider that breaking the vicious circle of IGF-1 feeding the metastatic tumor was key for the long-term outcome of this case

An innovative social enterprise: roles of and challenges faced by an arts hub in a World Heritage Site in Malaysia

This research examines the roles of an arts hub in George Town, Malaysia, a UNESCO World Heritage Site. Operating largely as a social enterprise, it has fostered links between the local cultural sector, international arts actors, local communities, and tourists. But this innovative approach does encounter some challenges. This research employed a structured questionnaire and in-depth interviews with key persons, to understand the adopted management strategies and innovation practices. The arts hub has converted a derelict bus depot into an arts space serving both artists and local communities. This place-making effort has gained international acclaims for its innovations and community engagement. But it is a “meanwhile” space, precarious in nature due to land development threats as it is located at the edge of the old city centre, just outside of the world heritage site regulated zone. It also faces challenges in financial sustainability; further innovation in its business model is warranted particularly in revenue model innovation and partnership-building with the public sector and the tourism industry. The organisation is the focal point of an extended international and local art community in a mini-entrepreneurial ecosystem. It survives by finding innovative ways, taking some risks to obtain resources, retain and nurture talent, and reach out to the community. The research helps to provide a greater understanding of the potential roles and challenges faced by innovative social enterprises in the cultural and creative sector worldwide

Society for Endocrinology (SfE) guidelines for the diagnosis and management of post bariatric hypoglycaemia

Post-bariatric hypoglycaemia (PBH) is typically a post-prandial hypoglycaemia occurring about 2–4 h after eating in individuals who have undergone bariatric surgery. PBH develops relatively late after surgery and often after discharge from post-surgical follow-up by bariatric teams, leading to variability in diagnosis and management in non-specialist centres.AimThe overall aim was to improve and standardise clinical practice in the diagnosis and management of PBH. The objectives were: (1) to undertake an up-to-date review of the current literature; (2) to formulate practical and evidence-based guidance regarding the diagnosis and treatment of PBH; (3) to recommend future avenues for research in this condition.MethodA scoping review was undertaken after an extensive literature search. A consensus on the guidance and confidence in the recommendations was reached by the steering group authors prior to review by key stakeholders.OutcomeWe make pragmatic recommendations for the practical diagnosis and management of PBH, including criteria for diagnosis and recognition, as well as recommendations for research areas that should be explored.Plain English summaryPost-bariatric hypoglycaemia (PBH) is a condition that commonly affects people who have undergone weight loss surgery. In this condition, people develop low blood sugar occurring about 2–4 h after meals, leading to debilitating symptoms such as hunger, sweating, anxiety, palpitations and even blackouts and fainting. PBH is becoming more common as weight loss surgery is being taken up by more people to help with their weight and to help with diabetes. The condition often develops after the patient has been discharged from follow-up after their surgery, which can lead to inconsistent diagnosis and treatment in non-specialist healthcare centres. The lack of clear information and evidence in the existing scientific literature further contributes to the variation in care. To address this problem, the Society for Endocrinology has created new guidelines to help healthcare professionals accurately diagnose and manage this condition. The guidelines were developed with input from dietitians, surgeons and doctors specialising in weight loss, and hormone specialists

Hypoglycaemia following upper gastrointestinal surgery: case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Hyperinsulinemic hypoglycemia is relatively recently recognized in persons undergoing bariatric surgery although knowledge and experience with this condition may not be commensurate with the number of such procedures being performed globally. This paper presents a novel case as an example of how such patients may present and how they may be investigated.</p> <p>Case Presentation</p> <p>A 69-year-old man was assessed 3 months post-fundoplication surgery for postprandial hypoglycaemia with neuroglycopenia that became progressively severe. A 72-h fast failed to show hypoglycaemia. During a clinic visit, the patient became confused and had a low plasma glucose, high plasma insulin, and high plasma C-peptide; symptoms were relieved with glucose. No tumours were visualized on CT, MRI, or endoscopic ultrasound. A total body Indium111-octreotide scan was negative. Selective arterial calcium stimulation showed a high insulin gradient in the splenic and superior mesenteric arteries, suggesting diffuse pancreatic beta cell hyperplasia. The patient declined pancreatic resection and recurrent symptomatic hypoglycaemia was successfully prevented with low dose octreotide.</p> <p>Conclusions</p> <p>Although increasingly recognized following bariatric surgery, this is the first reported development of NIPHS (non-insulinoma pancreatogenous hypoglycemia syndrome) following fundoplication surgery, as well as the first documented use of octreotide in post-operative NIPHS. Medical management may be an alternative to surgery for patients with this rare condition.</p

Genomic expression and single-nucleotide polymorphism profiling discriminates chromophobe renal cell carcinoma and oncocytoma

<p>Abstract</p> <p>Background</p> <p>Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, oncocytoma is usually regarded as a benign entity. The overlapping characteristics are best explained by a common cellular origin, and the biologic differences between chRCC and oncocytoma are therefore of considerable interest in terms of carcinogenesis, diagnosis and clinical management. Previous studies have been relatively limited in terms of examining the differences between oncocytoma and chromophobe RCC.</p> <p>Methods</p> <p>Gene expression profiling using the Affymetrix HGU133Plus2 platform was applied on chRCC (n = 15) and oncocytoma specimens (n = 15). Supervised analysis was applied to identify a discriminatory gene signature, as well as differentially expressed genes. High throughput single-nucleotide polymorphism (SNP) genotyping was performed on independent samples (n = 14) using Affymetrix GeneChip Mapping 100 K arrays to assess correlation between expression and gene copy number. Immunohistochemical validation was performed in an independent set of tumors.</p> <p>Results</p> <p>A novel 14 probe-set signature was developed to classify the tumors internally with 93% accuracy, and this was successfully validated on an external data-set with 94% accuracy. Pathway analysis highlighted clinically relevant dysregulated pathways of c-erbB2 and mammalian target of rapamycin (mTOR) signaling in chRCC, but no significant differences in p-AKT or extracellular HER2 expression was identified on immunohistochemistry. Loss of chromosome 1p, reflected in both cytogenetic and expression analysis, is common to both entities, implying this may be an early event in histogenesis. Multiple regional areas of cytogenetic alterations and corresponding expression biases differentiating the two entities were identified. Parafibromin, aquaporin 6, and synaptogyrin 3 were novel immunohistochemical markers effectively discriminating the two pathologic entities.</p> <p>Conclusions</p> <p>Gene expression profiles, high-throughput SNP genotyping, and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. A cytogenetic alteration, loss of chromosome 1p, common to renal oncocytoma and chRCC has been identified, providing the opportunities for identifying novel tumor suppressor genes and we have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma.</p

Assessment and Management of Anti-insulin Autoantibodies in Varying Presentations of Insulin Autoimmune Syndrome

Context: Insulin autoimmune syndrome (IAS), spontaneous hyperinsulinemic hypoglycemia due to insulin-binding autoantibodies, may be difficult to distinguish from tumoral or other forms of hyperinsulinemic hypoglycemia including surreptitious insulin administration. No standardized treatment regimen exists. Objectives: To evaluate an analytic approach to IAS and responses to different treatments. Design and Setting: Observational study in the UK Severe Insulin Resistance Service. Patients: 6 patients with hyperinsulinemic hypoglycemia and detectable circulating anti-insulin antibody (IA). Main outcome measures: Glycemia, plasma insulin and C-peptide concentrations by immunoassay or mass spectrometry (MS). Immunoreactive insulin was determined in the context of polyethylene glycol (PEG) precipitation and gel filtration chromatography (GFC). IA quantification using enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), and IA were further characterized using radioligand binding studies. Results: All patients were diagnosed with IAS (5 IgG, 1 IgA) based on high insulin:C-peptide ratio, low insulin recovery after PEG precipitation, and GFC evidence of antibody-bound insulin. Neither ELISA nor RIA result proved diagnostic for every case. MS provided a more robust quantification of insulin in the context of IA. 1 patient was managed conservatively, 4 were treated with diazoxide without sustained benefit, and 4 were treated with immunosuppression with highly variable responses. IA affinity did not appear to influence presentation or prognosis. Conclusions: IAS should be considered in patients with hyperinsulinemic hypoglycemia and a high insulin:C-peptide ratio. Low insulin recovery on PEG precipitation supports the presence of insulin-binding antibodies, with GFC providing definitive confirmation. Immunomodulatory therapy should be customized according to individual needs and clinical response