Threshold-based prediction of the coagulation zone in sequential temperature mapping in MR-guided radiofrequency ablation of liver tumours

Objective

To evaluate different cut-off temperature levels for a threshold-based prediction of the coagulation zone in magnetic resonance (MR)-guided radiofrequency (RF) ablation of liver tumours.

Methods

Temperature-sensitive measurements were acquired during RF ablation of 24 patients with primary (6) and secondary liver lesions (18) using a wide-bore 1.5?T MR sytem and compared with the post-interventional coagulation zone. Temperature measurements using the proton resonance frequency shift method were performed directly subsequent to energy application. The temperature maps were registered on the contrast-enhanced follow-up MR images acquired 4?weeks after treatment. Areas with temperatures above 50°, 55° and 60°C were segmented and compared with the coagulation zones. Sensitivity and positive predictive value were calculated.

Results

No major complications occurred and all tumours were completely treated. No tumour recurrence was observed at the follow-up examination after 4?weeks. Two patients with secondary liver lesions showed local tumour recurrence after 4 and 7?months. The 60°C threshold level achieved the highest positive predictive value (87.7?±?9.9) and the best prediction of the coagulation zone.

Conclusions

For a threshold-based prediction of the coagulation zone, the 60°C cut-off level achieved the best prediction of the coagulation zone among the tested levels.

Key Points

? Temperature monitoring can be used to survey MR-guided radiofrequency ablation ? The developing ablation zone can be estimated based on post-interventional temperature measurements ? A 60°C threshold level can be used to predict the ablation zone ? The 50°C and 55°C temperature zones tend to overestimate the ablation zone     

Assessing quality of life in primary biliary cirrhosis.

BACKGROUND AND AIMS: Assessment of health-related quality of life (HRQOL) is not routinely reported in the literature on chronic liver disease (CLD). Few studies have examined quality of life (QOL) in patients with primary biliary cirrhosis (PBC) despite its significant functional impact. One of the reasons for the lack of HRQOL measurement in patients with PBC may be the absence of a well-recognized and widely used measure that clinicians can use in ordinary clinical practice. The aim of this study is to evaluate HRQOL measures used in patients with PBC and examine the suitability of the measures for these patients. METHODS: A literature search identified reports that focused on any aspect of QOL in patients with PBC. Key texts were identified containing generic, domain-specific, and condition-specific measures. The identified measures were systematically evaluated for appropriateness, acceptability, reliability, validity, precision, and responsiveness. RESULTS: Twenty measures were identified from 9 key texts. Six of the measures were previously validated generic measures; 10 were domain-specific measures previously used to measure fatigue, depression, and psychological distress in general and psychiatric populations; and 4 measures had been developed in patients with CLD. Reporting of reliability and validity generally was consistent for all measures used. However, reporting of the remaining criteria was variable, particularly in relation to responsiveness over time and acceptability of the measures to patients with PBC. CONCLUSIONS: A clearer and more rigorous approach is needed in reporting the properties of HRQOL measures used in patients with PBC to help clinicians decide which measures are most suitable for these patients.     

The syntaxin binding protein 1 gene (Stxbp1) is a candidate for an ethanol preference drinking locus on mouse chromosome 2

BACKGROUND: We previously mapped a quantitative trait locus (QTL) for ethanol preference drinking to mouse chromosome 2 (mapped with high confidence, LOD = 15.5, p = 3 x 10(-16)). The specific gene(s) in the QTL interval responsible for phenotypic variation in ethanol preference drinking has not been identified. METHODS: In the current study, we investigated the association of the syntaxin binding protein 1 gene (Stxbp1) with ethanol preference drinking and other ethanol traits using a panel of B6 x D2 (BXD) recombinant inbred (RI) strains derived from the C57BL/6J (B6) and DBA/2J (D2) inbred mouse strains. Confirmation analyses for ethanol consumption and withdrawal were performed using a large B6D2 F2 cross, short-term selected lines derived from the B6 and D2 progenitor strains, and standard inbred strains. RESULTS: BXD RI strain analysis detected provisional associations between Stxbp1 molecular variants and ethanol consumption, as well as severity of acute ethanol withdrawal, ethanol-conditioned taste aversion, and ethanol-induced hypothermia. Confirmation analyses using three independent genetic models supported the involvement of Stxbp1 in ethanol preference drinking but not in ethanol withdrawal. CONCLUSIONS: Stxbp1 encodes a Sec1/Munc18-type protein essential for vesicular neurotransmitter release. The present study provides supporting evidence for the involvement of Stxbp1 in ethanol preference drinking.     

Proton magnetic resonance spectroscopy characteristics of a focal cortical dysgenesis during status epilepticus and in the interictal state.

We report the magnetic resonance imaging and proton magnetic resonance spectroscopic findings ((1)HMRS) in a patient with a focal cortical dysgenesis in the right superior frontal gyrus during intermittent frontal status epilepticus (IFSE) with simple partial seizures, and after she had become seizure free. During the status epilepticus, demonstrated by simultaneous behavioural and electroencephalographic telemetric long-term monitoring with scalp electrodes and ictal SPECT, we performed a single voxel spectroscopy of the dysgenic cortex. The(1)HMRS was repeated after 20 days when the patient's seizures were controlled.The N-acetyl-aspartate concentration in the focal dysgenic cortex was decreased in the interictal state but more during IFSE. The creatine/phosphocreatine concentration was normal in both instances. There was a clear lactate signal during IFSE, which was no longer visible in the interictal state.To our knowledge this is the first report of a(1)HMRS study of a focal cortical dysgenesis during an intermittent status epilepticus. We interpret the observed changes as signs of histopathological changes inherent to a cortical malformation and of an impaired energy metabolism due to the partial status epilepticus.     

Identifying genes for alcohol and drug sensitivity: recent progress and future directions

New methods for identifying chromosomal regions containing genes that affect murine responses to alcohol and drugs have been used to identify many provisional quantitative trait loci (QTLs) since 1991. By 1998, 24 QTLs had been definitively mapped (P<5x10(-5)) to specific murine chromosomes, which indicates the presence of a relevant gene or genes at each location. The syntenic (homologous) region of the human genome for these genes is often known. For many mapped QTLs, candidate genes with relevant neurobiological function lie within the mapped region. Data that implicate candidate genes for specific responses include studies of knockout animals. Current strategies for gene identification include the use of congenic strains containing QTL regions introduced from another strain. There is increasing emphasis on gene-gene and gene-environment interactions in such studies.     

Mild dystrophic damage in the androgen-sensitive levator ani muscle of the mdx mouse

The time course of muscular dystrophy on the androgen-sensitive levator ani muscle was compared to that of the diaphragm of dystrophic (mdx) mice aged 1-20 months. Muscle growth, isometric contractile properties and caffeine-induced contractures were determined to assess the hormone myotrophic effect, muscle strength and sarcoplasmic reticulum function, respectively, of both control and dystrophic muscles. Histological analysis of mdx muscles showed variable fiber size, centronucleated cells, infiltration of connective tissue, and necrosis which was less severe in the levator ani than in the diaphragm muscle. Tetanic tension per unit weight in the mdx levator ani was reduced (29%) after aging, while the contraction time remained unchanged. The tetanic tension of the mdx diaphragm muscle decreased with age from 3 to 20 months (20-64%), and the relaxation time was prolonged after aging (22%). Gonadectomy of young adult mdx mice caused atrophy of the levator ani muscle, accelerated muscle wasting, reduced the tetanic force (31%), but it did not affect the contraction time and caffeine responses. The results showed that testosterone does not prevent the progress of muscle disease in the mdx levator ani, but androgen withdrawal accelerates muscle wasting suggesting a normonal beneficial effect.     

Calcium-sensing soluble adenylyl cyclase mediates TNF signal transduction in human neutrophils

Through chemical screening, we identified a pyrazolone that reversibly blocked the activation of phagocyte oxidase (phox) in human neutrophils in response to tumor necrosis factor (TNF) or formylated peptide. The pyrazolone spared activation of phox by phorbol ester or bacteria, bacterial killing, TNF-induced granule exocytosis and phox assembly, and endothelial transmigration. We traced the pyrazolone's mechanism of action to inhibition of TNF-induced intracellular Ca2+ elevations, and identified a nontransmembrane ("soluble") adenylyl cyclase (sAC) in neutrophils as a Ca2+-sensing source of cAMP. A sAC inhibitor mimicked the pyrazolone's effect on phox. Both compounds blocked TNF-induced activation of Rap1A, a phox-associated guanosine triphosphatase that is regulated by cAMP. Thus, TNF turns on phox through a Ca2+-triggered, sAC-dependent process that may involve activation of Rap1A. This pathway may offer opportunities to suppress oxidative damage during inflammation without blocking antimicrobial function.