Text-based discovery in biomedicine: the architecture of the DAD-system.
Current scientific research takes place in highly specialized contexts with poor communication between disciplines as a likely consequence. Knowledge from one discipline may be useful for the other without researchers knowing it. As scientific publications are a condensation of this knowledge, literature-based discovery tools may help the individual scientist to explore new useful domains. We report on the development of the DAD-system, a concept-based Natural Language Processing system for PubMed citations that provides the biomedical researcher such a tool. We describe the general architecture and illustrate its operation by a simulation of a well-known text-based discovery: The favorable effects of fish oil on patients suffering from Raynaud's disease . (+info)
Assessment of microvascular changes in Raynaud's phenomenon and connective tissue disease using colour doppler ultrasound.
OBJECTIVE: We used colour Doppler ultrasound (CDU) to differentiate primary from secondary Raynaud's phenomenon (pRP and sRP, respectively) and to assess digital vascular damage in patients with connective tissue disease (CTD). METHODS: Vascularity in the nailbeds of 15 healthy controls and 35 patients with CTD (systemic sclerosis or systemic lupus erythematosus) was quantified using a multi-D array transducer before and after cold and warm challenge, respectively. The results were compared with the clinically evaluated initial skin lesions. Vascularity was compared similarly between 10 pRP and 22 sRP patients. RESULTS: Vascularity at ambient temperature differed between healthy subjects and sRP patients as well as between healthy subjects and CTD patients without initial skin lesions. Patients with pRP had normal vascularity at ambient temperature but differed from healthy controls in response to a dynamic temperature challenge. CDU confirmed the clinical evaluation in 89.4% of the patients with RP and in 78.0% of the skin lesions. CONCLUSION: The novel CDU technique presented here makes it possible to discriminate between pRP and sRP and to quantify vascular changes in CTD patients. (+info)
The cytokine interferon-alpha (IFN-alpha) is increasingly prescribed for a number of indications, especially viral hepatitis and several malignancies. Two patients are described who developed Raynaud's syndrome during treatment with IFN-alpha as adjuvant therapy for high-risk melanoma. With a review of the available literature the symptomatology, possible pathophysiologic mechanisms and treatment options are discussed. (+info)
Acute congestive heart failure associated with a limited form of systemic sclerosis and primary biliary cirrhosis.
This is the first case of a limited form of systemic sclerosis (ISSc) associated with acute congestive heart failure (CHF) and primary biliary cirrhosis (PBC). A 58-year-old woman with ISSc was admitted because of a sudden onset of CHF. The intravenous administration of nitroglycerine and furosemide ameliorated the symptoms of CHF within 24 hours. She had both anticentromere antibodies and anti-p25 doublet/triplet antibodies to intrahepatic microsomes. Thallium scintigraphy at rest demonstrated significant perfusion defects in both the anteroseptal and inferior myocardium. A coronary angiogram revealed normal coronary arteries and no vasospasm was provoked by the intracoronary administration of acetylcholine. The present case indicates that minute care should thus be taken for the prevention of acute CHF even in patients with a limited form of SSc when thallium perfusion defects are identified. (+info)
Differentiation between primary and secondary Raynaud's phenomenon: a prospective study comparing nailfold capillaroscopy using an ophthalmoscope or stereomicroscope.
BACKGROUND: Nailfold capillary microscopy is a routine procedure in the investigation of patients with Raynaud's phenomenon (RP). As a standard method, nailfold capillary morphology is inspected with a stereomicroscope to look for capillary abnormalities such as giant loops, avascular areas, and bushy capillaries, which have all been found to be associated with certain connective tissue diseases. AIM: To investigate prospectively whether nailfold capillary inspection using an ophthalmoscope is of equivalent diagnostic value to standard nailfold capillary microscopy. METHOD: All the fingers of 26 patients with RP were examined in a blinded fashion and compared with the final diagnosis one month later. RESULTS: All giant loops, large avascular areas, and bushy capillaries were identified by both methods. The correlation for moderate avascular areas and crossed capillaries was 0.93 and 0.955 respectively. The correlation for minor abnormalities that do not contribute to the differentiation between primary and secondary RP was 0.837 and 0.861 respectively. All patients were classified identically by the two methods. CONCLUSION: For the evaluation of patients with RP, nailfold capillary morphology can reliably be assessed with an ophthalmoscope. (+info)
Thenar muscle blood flow and bone mineral in the forearms of lumberjacks.
Forty lumberjacks who had used a chain saw for 0-20 years and who had no general disease affecting the bones were studied by measuring the thenar muscle blood flow of both hands by the 133-Xe local clearance method. Bone mineral in the left forearm in the region of cancellous and cortical bone was assessed by the 241-Am gamma ray attenuation method. Virbration was found to decrease the blood flow in the saw-bearing left hand compared with the right hand of the lumberjacks. The bone mineral density (g/vm-3) was lower in the forearm bones of the lumberjacks than in controls of the same age with healthy bones. Moreover the poorer the thenar muscle blood flow, the greater was the decrease in the mineral density of the distal radius. Measurement of the mineral density of the forearm bones by the gramma ray attenuation method can be used for early detection of bone lesions in traumatic vasospastic disease. (+info)
Increased urinary pyridinoline cross-link compounds of collagen in patients with systemic sclerosis and Raynaud's phenomenon.
OBJECTIVE: To study concentration changes in collagen degradation markers in patients with diffuse and limited cutaneous systemic sclerosis and patients with scleroderma-related diseases. METHODS: Pyridinoline cross-link compounds were analysed in urine samples using high-performance liquid chromatography. Samples were analysed for pyridinoline (Pyr), deoxypyridinoline (Dpyr) and soft-tissue pyridinoline (stPyr) in patients with diffuse cutaneous systemic sclerosis (dcSSc, n=23) and limited cutaneous systemic sclerosis (lcSSc, n=48) and in patients with scleroderma-related diseases such as primary Raynaud's phenomenon (pRP, n=16) and secondary Raynaud's phenomenon (sRP, n=14). Healthy controls (n=18) and patients with post-menopausal osteoporosis (OP, n=35) were also investigated. RESULTS: Urinary Pyr, Dpyr and stPyr concentrations were significantly higher in patients with Raynaud's phenomenon and systemic sclerosis than in healthy controls. The highest concentrations (two to three times greater than in healthy controls) were found in patients with dcSSc. The stPyr concentration was significantly higher in patients with dcSSc than in those with lcSSc, sRP and pRP. No significant difference in stPyr concentration was found between the healthy controls and the OP group, suggesting that stPyr is derived from soft tissues rather than bone. The extent and severity of skin involvement, measured as a skin score, significantly correlated with the concentrations of stPyr and Pyr, whereas no such correlation was found for Dpyr. CONCLUSIONS: Increased urinary concentrations of piridinoline cross-links reflect alterations in collagen turnover in both Raynaud's phenomenon and systemic sclerosis. The close correlation between stPyr concentration and the extent of skin involvement in systemic sclerosis suggests that this parameter may be useful in monitoring ongoing fibrosis in this disease. (+info)
The analysis of sensitivity, specificity, positive predictive value and negative predictive value of cold provocation thermography in the objective diagnosis of the hand-arm vibration syndrome.
The diagnosis of digital artery vasospasm in the hand-arm vibration syndrome (HAVS) is clinically based, and the need for an accurate objective test to support the diagnosis has been highlighted. This study aims to analyse the potential of cold provocation thermography (CPT) to fulfill this role. CPT was performed on two groups of subjects: 10 controls and 21 patients with Raynaud's phenomenon (RP) secondary to HAVS. After taking a pre-cooling image, patients donned latex gloves and immersed their hands in water at a temperature of 5 degrees C for 1 min. The patients removed their hands from the water and discarded the gloves, and further images were taken every 30 s for 10 min. On each image, the temperatures of the tip and base were analysed for each digit. The sensitivity, specificity, positive and negative predictive values for fingertip temperatures only, fingertip and fingerbase temperatures combined, and fingertip temperature, fingerbase temperature and temperature gradient combined were determined. Patients with RP secondary to HAVS demonstrated significantly lower finger tip and base temperatures and lower digital temperature gradients at all time intervals when compared with controls (P < 0.01, Student's t-test). CPT has good sensitivity, specificity, positive predictive value and negative predictive value; it strongly supports the clinical diagnosis of digital vasospasm. (+info)