313 research outputs found
Making Thermal Imaging More Equitable and Accurate: Resolving Solar Loading Biases
Thermal cameras and thermal point detectors are used to measure the
temperature of human skin. These are important devices that are used everyday
in clinical and mass screening settings, particularly in an epidemic.
Unfortunately, despite the wide use of thermal sensors, the temperature
estimates from thermal sensors do not work well in uncontrolled scene
conditions. Previous work has studied the effect of wind and other environment
factors on skin temperature, but has not considered the heating effect from
sunlight, which is termed solar loading. Existing device manufacturers
recommend that a subject who has been outdoors in sun re-acclimate to an indoor
environment after a waiting period. The waiting period, up to 30 minutes, is
insufficient for a rapid screening tool. Moreover, the error bias from solar
loading is greater for darker skin tones since melanin absorbs solar radiation.
This paper explores two approaches to address this problem. The first approach
uses transient behavior of cooling to more quickly extrapolate the steady state
temperature. A second approach explores the spatial modulation of solar
loading, to propose single-shot correction with a wide-field thermal camera. A
real world dataset comprising of thermal point, thermal image, subjective, and
objective measurements of melanin is collected with statistical significance
for the effect size observed. The single-shot correction scheme is shown to
eliminate solar loading bias in the time of a typical frame exposure (33ms)
The impact of diabetes mellitus on survival following resection and adjuvant chemotherapy for pancreatic cancer
BACKGROUND: Diabetes mellitus is frequently observed in pancreatic cancer patients and is both a risk factor and an early manifestation of the disease. METHODS: We analysed the prognostic impact of diabetes on the outcome of pancreatic cancer following resection and adjuvant chemotherapy using individual patient data from three European Study Group for Pancreatic Cancer randomised controlled trials. Analyses were carried out to assess the association between clinical characteristics and the presence of preoperative diabetes, as well as the effect of diabetic status on overall survival. RESULTS: In total, 1105 patients were included in the analysis, of whom 257 (23%) had confirmed diabetes and 848 (77%) did not. Median (95% confidence interval (CI)) unadjusted overall survival in non-diabetic patients was 22.3 (20.8–24.1) months compared with 18.8 (16.9–22.1) months for diabetic patients (P=0.24). Diabetic patients were older, had increased weight and more co-morbidities. Following adjustment, multivariable analysis demonstrated that diabetic patients had an increased risk of death (hazard ratio: 1.19 (95% CI 1.01, 1.40), P=0.034). Maximum tumour size of diabetic patients was larger at randomisation (33.6 vs 29.7 mm, P=0.026). CONCLUSIONS: Diabetes mellitus was associated with increased tumour size and reduced survival following pancreatic cancer resection and adjuvant chemotherapy
The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom
Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH
Successful treatment of pediatric IgG4 related systemic disease with mycophenolate mofetil: case report and a review of the pediatric autoimmune pancreatitis literature
Autoimmune pancreatitis is frequently associated with elevated serum and tissue IgG4 levels in the adult population, but there are few reports of pediatric autoimmune pancreatitis, and even fewer reports of IgG4 related systemic disease in a pediatric population. The standard of care treatment in adults is systemic corticosteroids with resolution of symptoms in most cases; however, multiple courses of corticosteroids are occasionally required and some patients require long term corticosteroids. In these instances, steroid sparing disease modify treatments are in demand. We describe a 13-year-old girl with IgG4 related systemic disease who presented with chronic recurrent autoimmune pancreatitis resulting in surgical intervention for obstructive hyperbilirubinemia and chronic corticosteroid treatment. In addition, she developed fibrosing medianstinitis as part of her IgG4 related systemic disease. She was eventually successfully treated with mycophenolate mofetil allowing for discontinuation of corticosteroids. This is the first reported use of mycophenolate mofetil for IgG4 related pancreatitis. Although autoimmune pancreatitis as part of IgG4 related systemic disease is rarely reported in pediatrics, autoimmune pancreatitis is also characterized as idiopathic fibrosing pancreatitis. All pediatric autoimmune pancreatitis cases reported in the world medical literature were identified via a PUBMED search and are reviewed herein. Twelve reports of pediatric autoimmune pancreatitis were identified, most of which were treated with corticosteroids or surgical approaches. Most case reports failed to report IgG4 levels, so it remains unclear how commonly IgG4 related autoimmune pancreatitis occurs during childhood. Increased evaluation of IgG4 levels in patients with autoimmune pancreatitis may shed further light on the association of IgG4 with pancreatitis and the underlying pathophysiology
Autoimmune cholangitis mimicking a klatskin tumor: a case report
<p>Abstract</p> <p>Introduction</p> <p>Autoimmune cholangitis remains an elusive manifestation of immunoglobulin G4-associated systemic disease most commonly encountered in patients with autoimmune pancreatitis. No strict diagnostic criteria have been described to date and diagnosis mainly relies on a combination of clinical and histopathologic findings. It is hence even more challenging to diagnose autoimmune cholangitis in patients with late or atypical presentations, such as without concomitant pancreatic involvement. Early diagnosis of this rare disorder can significantly improve outcomes considering high rates of surgical intervention, as well as high relapse rates in the absence of steroid treatment. To the best of our knowledge the literature is quite sparse on cases with atypical presentations of autoimmune cholangitis.</p> <p>Case presentation</p> <p>We report a case of a previously healthy 65-year-old man of Middle-Eastern origin, with a history of pancreatic insufficiency of unknown etiology, evaluated for elevated liver function tests found incidentally on a routine physical examination. Imaging studies revealed an atrophic pancreas and biliary duct dilatation consistent with obstruction. Subsequent endoscopic retrograde cholangiopancreatography showed a bile duct narrowing pattern suggestive of cholangiocarcinoma, but brushings failed to reveal malignant cells. Our patient proceeded to undergo surgical resection. Histological examination of the resected mass revealed lymphoplasmacytic infiltrate with no malignant features. Our patient returned three months later with persistently high liver function tests and no evidence of biliary obstruction on imaging. A presumptive diagnosis of autoimmune cholangitis was made and our patient's symptoms resolved after a short course of an oral steroid regimen. Post factum staining of the resection specimen revealed an immunoglobulin G4 antibody positive immune cell infiltrate, consistent with the proposed diagnosis.</p> <p>Conclusion</p> <p>Our case thus highlights the importance of clinician awareness of the autoimmune spectrum of biliary pathologies when confronted with atypical clinical presentations, the paucity of diagnostic measures and the benefit from long-term steroid and/or immunosuppressive treatment.</p
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Redirecting research efforts on the diversification-performance linkage: The search for synergy
We review the literature on the diversification-performance (D-P) relationship to a) propose that the time is ripe for a renewed attack on understanding the relationship between diversification and firm performance, and b) outline a new approach to attacking the question. Our paper makes four main contributions. First, through a review of the literature we establish the inherent complexities in the D-P relationship and the methodological challenges confronted by the literature in reaching its current conclusion of a non-linear relationship between diversification and performance. Second, we argue that to better guide managers the literature needs to develop along a complementary path – whereas past research has often focused on answering the big question of does diversification affect firm performance, this second path would focus more on identifying the precise micro-mechanisms through which diversification adds or subtracts value. Third, we outline a new approach to the investigation of this topic, based on (a) identifying the precise underlying mechanisms through which diversification affects performance; (b) identifying performance outcomes that are “proximate” to the mechanism that the researcher is studying, and (c) identifying an appropriate research design that can enable a causal claim. Finally, we outline a set of directions for future research
An unusual case of autoimmune pancreatitis presenting as pancreatic mass and obstructive jaundice: a case report and review of the literature
<p>Abstract</p> <p>Background</p> <p>Autoimmune pancreatitis is a rare chronic inflammatory pancreatic disease that is increasingly being diagnosed worldwide. As a result of overlap in clinical and radiological features, it is often misdiagnosed as pancreatic cancer. We report the case of a patient with autoimmune pancreatitis that was initially misdiagnosed as pancreatic cancer.</p> <p>Case presentation</p> <p>A 31-year-old Caucasian man presented to our hospital with epigastric pain, jaundice and weight loss. His CA 19-9 level was elevated, and computed tomography and endoscopic ultrasound revealed a pancreatic head mass abutting the portal vein. Endoscopic retrograde cholangiopancreaticography showed narrowing of the biliary duct and poor visualization of the pancreatic duct. Fine-needle aspiration biopsy revealed atypical ductal epithelial cells, which raised clinical suspicion of adenocarcinoma. Because of the patient's unusual age for the onset of pancreatic cancer and the acuity of his symptoms, he was referred to a tertiary care center for further evaluation. His immunoglobulin G4 antibody level was 365 mg/dL, and repeat computed tomography showed features typical of autoimmune pancreatitis. The patient's symptoms resolved with corticosteroid therapy.</p> <p>Conclusion</p> <p>Autoimmune pancreatitis is a rare disease with an excellent response to corticosteroid therapy. Its unique histological appearance and response to corticosteroid therapy can reduce unnecessary surgical procedures. A thorough evaluation by a multidisciplinary team is important in rendering the diagnosis of autoimmune pancreatitis.</p
Potent inhibitory effect of alcoholic beverages upon gastrointestinal passage of food and gallbladder emptying
Intraductal papillary mucinous neoplasm of the pancreas (IPMN): clinico-pathological correlations and surgical indications
<p>Abstract</p> <p>Background</p> <p>Intraductal papillary mucinous neoplasms (IPMNs) are increasingly recognized entities, whose management remains sometimes controversial, due to the high rate of benign lesions and on the other side to the good survival after resection of malignant ones.</p> <p>Methods</p> <p>Retrospective analysis of a prospectively collected Western series of IPMN.</p> <p>Results</p> <p>Forty cases of IPMN were analysed (1992-2007). Most patients were symptomatic (72.5%); cholangio-MRI had the best diagnostic accuracy both for the tumour nature (83.3%) and for the presence of malignancy (57.1%). ERCP was done in 8 cases (20%), and the results were poor. Thirteen patients were treated by pancreatic resection and 27 were maintained in follow-up. Total pancreatectomy was performed in 46% of the cases; in situ and invasive carcinoma were recognized in 15.4% and 38.4% of the cases, respectively. The mean follow-up was 42 months (range 12-72). One only patients with nodal metastases died 16 months after the operation for disease progression, while 91.6% of the operated patients are disease free. Out of the 27 not resected patients, 2 out of 4 presenting a lesion at high risk for malignancy died, while the remaining are in good conditions and disease free, with a mean follow-up of 31 months.</p> <p>Conclusion</p> <p>Therapeutic indication for IPMNs is mainly based upon radiological evaluation of the risk of malignancy. While the main duct tumours should be resected, preserving whenever possible a portion of the gland, the secondary ducts tumours may be maintained under observation, in absence of radiological elements of suspicion such as size larger than 3 cm, or a wall greater than 3 mm or nodules or papillae in the context of the cyst.</p
Pancreatic Ductal Adenocarcinoma Associated with Autoimmune Pancreatitis
Autoimmune pancreatitis (AIP), in contrast to other benign chronic pancreatic diseases, can be cured with immunosuppressant drugs, thus the differentiation of AIP from pancreatic cancer is of particular interest in clinical practice. There is the possibility that some patients with AIP may develop pancreatic cancer, and this possibility contributes to increasing our difficulties in differentiating AIP from pancreatic cancer. We herein report the case of a 70-year-old man in whom pancreatic adenocarcinoma and AIP were detected simultaneously. We must carefully monitor AIP patients for the simultaneous presence of pancreatic cancer, even when a diagnosis of AIP is confirmed
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