193 research outputs found
Improved Schmidt Conversion of Aldehydes to Nitriles Using Azidotrimethylsilane in 1,1,1,3,3,3-Hexafluoro-2-propanol
This work is licensed under a Creative Commons Attribution 4.0 International License.The Schmidt reaction of aromatic aldehydes using a substoichiometric amount (40 mol %) of triflic acid is described. Low catalyst loading was enabled by a strong hydrogen-bond-donating solvent hexafluoro-2-propanol (HFIP). This improved protocol tolerates a broad scope of aldehydes with diverse functional groups and the corresponding nitriles were obtained in good to high yields without the need for aqueous work up.University of Kansa
Dissociating anticipation from perception: Acute pain activates default mode network.
Few studies have explored the effect of acute pain on attentional networks and on the default mode network. Moreover, these studies convey conflicting results, seemingly caused by design. To reassess this issue, we studied 20 healthy subjects with functional magnetic resonance imaging while delivering painful electric shocks. The design was purposely constructed to separate rest, anticipation, and pain perception. We found that default mode network activity in response to pain was biphasic. It deactivated during anticipation when the dorsal attentional network was activated. During pain perception, the default mode network was activated, as were attentional networks. The left posterior fusiform gyrus showed the same dynamics as the default mode network, and its activity was negatively correlated to the subject\u27s pain intensity rating. The associative pregenual anterior cingulate cortex seemed to play a key role in these coactivations. These results concur with data from the literature showing that enhanced pain perception results in greater default mode network activity and that the anticorrelation between the default mode network and the dorsal attentional network disappears in chronic pain patients
Screening for significant chronic liver disease by using three simple ultrasound parameters
Objectives
Chronic liver diseases remain asymptomatic for many years. Consequently, patients are diagnosed belatedly, when cirrhosis is unmasked by lifethreatening complications. We aimed to identify simple ultrasound parameters for the screening of patients with unknown significant chronic liver disease.
Methods
Three hundred and twenty seven patients with chronic liver disease, liver biopsy, and ultrasound examination were included in the derivation set. 283 consecutive patients referred for ultrasound examination were included in the validation set; those selected according to the ultrasound parameters identified in the derivation set were then referred for specialized consultation including non-invasive fibrosis tests and ultimately liver biopsy if liver fibrosis was suspected.
Results
In the derivation set, three ultrasound parameters were independent predictors of severe fibrosis: liver surface irregularity, spleen length (>110Â mm), and demodulation of hepatic veins. The association of â„2 of the three above parameters provided 49.1% sensitivity and 86.9% specificity. In the validation set, at â„2 of the three parameters were present in 23 (8%) of the patients. Among these patients, 8 had liver fibrosis (FÂ â„Â 1), 5 had significant fibrosis (FÂ Â â„2) and two cirrhosis.
Conclusion
The generalized search of three simple ultrasound signs in patients referred for abdominal ultrasound examination may be an easy way to detect those with silent but significant chronic liver disease
MRI and venographic aspects of pelvic venous insufficiency.
Pelvic venous insufficiency is a frequent pathology in multiparous women. Diagnosis can be made by chance or suspected in the case of symptoms suggesting pelvic congestion syndrome or atypical lower limb varicosity fed by pelvic leaks. After ultrasound confirmation, dynamic venography is the reference pretherapeutic imaging technique, searching for pelvic varicosity and possible leaks to the lower limbs. MRI is less invasive and allows a three-dimensional study of the varicosity and, with dynamic angiography, it can assess ovarian reflux. It also helps to plan or even sometimes avoid diagnostic venography
Osteoprotegerin levels are associated with liver fat and liver markers in dysmetabolic adults
AIM: This study aimed to determine the association between visceral adipose tissue (VAT), liver fat (LF) content, and other markers of the metabolic syndrome (MetS) and osteoprotegerin (OPG) in dysmetabolic adults.
METHODS: Subjects from the NUMEVOX cohort were included if they fulfilled at least one MetS criterion. They then underwent a thorough metabolic and cardiovascular evaluation, including arterial stiffness, atherosclerotic plaques, homoeostasis model assessment for insulin resistance (HOMA-IR) indices and OPG. VAT and LF content were measured by magnetic resonance imaging (MRI). Ultrasound examination of arteries and arterial stiffness were recorded, and age- and gender-adjusted paired correlations calculated.
RESULTS: Body mass index, waist circumference and MRI-derived VAT correlated with OPG, whereas abdominal subcutaneous fat did not. OPG levels were strongly correlated with LF content (r=0.25, P=0.003), liver markers such as alanine aminotransferase (r=0.39, P<0.001) and HOMA-IR index (r=0.39, P<0.0001). Plasma OPG also correlated with arterial stiffness and the number of atherosclerotic sites.
CONCLUSION: Plasma OPG levels are positively associated with both liver markers and increased LF content, but not with subcutaneous fat in dysmetabolic men. These findings suggest that elevated OPG levels may play a role in the link between fatty liver disease and enhanced cardiovascular risk
Transarterial chemoembolisation: effect of selectivity on tolerance, tumour response and survival
Aims To compare selective and non-selective TACE techniques in the treatment of HCC with a special emphasis on clinical and liver tolerance, tumour response and survival. Methods 184 patients with advanced HCC were retrospectively included. Three different TACE techniques were compared: non selective lipiodol-chemotherapy + non selective embolisation (TACE-technique group 1), non selective lipiodol-chemotherapy + selective embolisation (group 2), and selective lipiodol-chemotherapy + selective embolisation (group 3). Results In multivariate analysis TACE-technique group is an independently significant prognostic factor for poor clinical tolerance, poor liver tolerance and tumour response. The rate of patients with poor clinical tolerance was lower in group 3 (27.0%) than in groups 1 (64.1%, p < 10â3) or 2 (66.7%, p < 10â3). The rate of patients with poor liver tolerance was higher in group 2 (34.0%) than in groups 1 (17.6%, p = 0.050) or 3 (6.9%, p = 0.011). The rate of patients with tumour response was higher when embolisation was selective versus non-selective, i.e., group 2 + 3 (78.7%) versus group 1 (62.5%, p = 0.054). Overall survival was not significantly different between the three groups (p = 0.383). Conclusion Both selective techniques resulted in better tumour response. As for improving tolerance, our study suggests that the main technical factor is the use of selective lipiodol-chemotherapy injection
Intra-arterial injection of lipid nanocapsules loaded with rhenium-188 for the radiotherapy of hepatocellular carcinomas in rats
International audienc
Uncommon evolutions and complications of common benign liver lesions
Frequently encountered on abdominal imaging studies, the majority of common benign liver lesions are asymptomatic, confidently diagnosed by imaging, and do not require further workup, follow-up, or treatment. The increasing use of multimodality liver imaging, has allowed the recognition of uncommon evolutions of common benign liver lesions such as size changes, fibrotic regression, and content and vascularization changes, and their complications such as rupture, hemorrhage, thrombosis, extrinsic compression, and malignancy. The purpose of this pictorial review is to describe and illustrate the incidence and diagnostic features of these uncommon evolutions and complications on cross-sectional imaging, mainly on computed tomography and magnetic resonance imaging, with emphasis on those imaging clues which are helpful in the differential diagnosis or indicate the need for treatment
Portosystemic collateral vessels in liver cirrhosis: a three-dimensional MDCT pictorial review
PURPOSE: Portosystemic collateral vessels (PSCV) are a consequence of the portal hypertension that occurs in chronic liver diseases. Their prognosis is strongly marked by the risk of digestive hemorrhage and hepatic encephalopathy.
MATERIALS AND METHODS: CT was performed with a 16-MDCT scanner. Maximum intensity projection and volume rendering were systematically performed on a workstation to analyze PSCV.
RESULTS: We describe the PSCV according to their drainage into either the superior or the inferior vena cava. In the superior vena cave group, we found gastric veins, gastric varices, esophageal, and para-esophageal varices. In the inferior vena cava group, the possible PSCV are numerous, with different sub groups: gastro and spleno renal shunts, paraumbilical and abdominal wall veins, retroperitoneal shunts, mesenteric varices, gallbladder varices, and omental collateral vessels. Regarding clinical consequences esophageal and gastric varices are most frequently involved in digestive bleeding; splenorenal shunts often lead to hepatic encephalopathy; the paraumbilical vein is an acceptable derivation pathway for natural decompression of the portal system.
CONCLUSION: Knowledge of precise cartography of PSCV is essential to therapeutic decisions. MDCT is the best way to understand and describe the different types of PSCV
Prevalence, correlates and impact of pain and cramps in anti-MAG neuropathy:a multicentre European study
BACKGROUND AND PURPOSE:Â The frequency of pain and cramps is uncertain in anti-myelin associated glycoprotein antibody (anti-MAG) neuropathy. Whether these symptoms may affect function/quality of life is unknown. METHODS: A cross-sectional study of the prevalence, correlates and impact of pain, pain subtypes and cramps, their severity, frequency and anatomical distribution was performed for 55 clinically stable patients with anti-MAG neuropathy. RESULTS: Pain of any type was reported by 80% of subjects. The most common subtype was paraesthesiae and dysaesthesiae (70%). Cramps were reported by >60% of patients, with lower limb cramps in all and upper limb cramps in about 20%. Cramps affected daily activities in >30% of these subjects, sleep in 60%, ability to exercise in >30%. Total pain score correlated with several Short Form 36 health-related quality of life (SF-36 HR-QoL) measures (PÂ <Â 0.05), with Inflammatory Rasch-built Overall Disability Scale (I-RODS) (PÂ =Â 0.006) and 10-m timed walk (PÂ =Â 0.019). An independent association was ascertained with I-RODS (PÂ =Â 0.002). Different pain subtypes showed multiple associations with SF-36 HR-QoL measures and/or functional scales. Upper limb cramps had multiple SF-36 HR-QoL functional correlates, with an independent association with the Overall Neuropathy Limitation Score (ONLS) (PÂ =Â 0.004). Cramp severity correlated with ONLS (PÂ =Â 0.04) and I-RODS (PÂ =Â 0.028) and inversely with level of physiotherapy input (PÂ =Â 0.009). Cramp frequency was associated with tremor score (PÂ =Â 0.004) and multiple SF-36 HR-QoL subsections. CONCLUSIONS: Neuropathic pain and cramps may affect function and quality of life in anti-MAG neuropathy. Optimizing treatments of these symptoms, including by adequate levels of physiotherapy, may be beneficial in affected patients and requires further research
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