Topography mapping of whole body adipose tissue using A fully automated and standardized procedure

Purpose:

To obtain quantitative measures of human body fat compartments from whole body MR datasets for the risk estimation in subjects prone to metabolic diseases without the need of any user interaction or expert knowledge.

Materials and Methods:

Sets of axial T1‐weighted spin‐echo images of the whole body were acquired. The images were segmented using a modified fuzzy c‐means algorithm. A separation of the body into anatomic regions along the body axis was performed to define regions with visceral adipose tissue present, and to standardize the results. In abdominal image slices, the adipose tissue compartments were divided into subcutaneous and visceral compartments using an extended snake algorithm. The slice‐wise areas of different tissues were plotted along the slice position to obtain topographic fat tissue distributions.

Results:

Results from automatic segmentation were compared with manual segmentation. Relatively low mean deviations were obtained for the class of total tissue (4.48%) and visceral adipose tissue (3.26%). The deviation of total adipose tissue was slightly higher (8.71%).

Conclusion:

The proposed algorithm enables the reliable and completely automatic creation of adipose tissue distribution profiles of the whole body from multislice MR datasets, reducing whole examination and analysis time to less than half an hour. J. Magn. Reson. Imaging 2010; 31: 430–439. © 2010 Wiley‐Liss, Inc.     

Hepatocerebral mitochondrial DNA depletion syndrome caused by deoxyguanosine kinase (DGUOK) mutations

BACKGROUND: Autosomal recessive mutations in deoxyguanosine kinase (DGUOK) have been identified in the hepatocerebral form of mitochondrial DNA (mtDNA) depletion syndrome. OBJECTIVES: To describe the clinical spectrum of DGUOK-related mtDNA depletion syndrome in 6 children and to summarize the literature. RESULTS: We identified pathogenic mutations in DGUOK in 6 children with the hepatocerebral form of mtDNA depletion syndrome. We describe the clinical, neuroradiologic, histologic, and genetic features in these children. All children showed severe hepatopathy, while involvement of other organs (skeletal muscle and brain) was variable. We identified 5 novel mutations (1 of them in 2 children) and 2 previously described mutations. Three different mutations affected the initial methionine, suggesting a mutational hot spot. One of our patients underwent liver transplantation; pathologic findings revealed (in addition to diffuse hepatopathy) a hepatocellular carcinoma, implying a possible link between mtDNA depletion syndrome and tumorigenesis. CONCLUSION: We studied 12 children with infantile hepatoencephalopathies and mtDNA depletion syndrome and found pathogenic DGUOK mutations in 6, suggesting that this gene defect is a frequent but not an exclusive cause of the hepatic form of mtDNA depletion syndrome.     

Cardiac channelopathy causing sudden death as revealed by molecular autopsy

Background

Mutations in cardiac ion channel genes have been identified to cause sudden unexplained deaths (SUD), and polymorphisms have also been suggested to be risk factors. Therefore, postmortem genetic testing has become an important tool in elucidating the cause of death.

Methods and results

In a sudden death case, a LQT-3-associated mutation (Il768V) in the cardiac sodium channel gene SCN5A was detected beside the common polymorphism H558R which is known to mitigate the effect of mutations in the gene. Both sequence variations were heterozygous. Large number of intervening base pairs make it impossible to identify whether they were located in cis or trans. Functional consequences of both variants were characterized after expressing different cRNAs in Xenopus oocytes by voltage clamp measurements. Western blot analysis indicates that the cis configuration of both variants may lead to a null allele. Since the woman had received an injection of Ultracain®, the potential effect of this drug was tested. In a trans configuration of both variants, the mutant channel exhibited an increase susceptibility of at least 10% for blocking with the drug articaine. Another novel finding is that the midpoint of activation in the case of the mutant channel is leftward shifted of at least ?10 mV.

Conclusion

The results of the study suggest that postmortem molecular screening is an important tool to elucidate the cause of SUD and that the administration of a drug and a functional interaction between polymorphisms and ion channel mutations may trigger the risk for sudden death.     

Perianale streptogene Dermatitis

Two boys aged 6 and 9 years presented with persistent sharply circumscribed perianal erythema. One boy had no other skin findings; the other had additional lesions on the genitalia and extremities. The diagnosis of perianal streptococcal dermatitis was made after streptococci were cultured from skin swabs. This primarily childhood disease should be distinguished from candidiasis and perianal atopic dermatitis. As in our cases, topical therapy is usually ineffective and oral penicillin remains the treatment of choice.     

Clinical experience with the pREset stent retriever for the treatment of acute ischemic stroke—a review of 271 consecutive cases

Introduction

The purpose of this study was to evaluate the safety and efficacy of the pREset stent retriever in a real-world clinical setting.

Methods

Patients treated with pREset were selected from a prospectively maintained single-center database. A TICI score ≥2b after ≤3 passes was regarded as successful recanalization. All device-related complications and their clinical significance were reported. Parenchymal hematomas (PH) were classified according to ECASS, adding focal and diffuse subarachnoid hemorrhage (SAH) as categories. A 90-day mRS of 0–2 was defined as favorable outcome. In addition, we separately analyzed patients treated with >3 pREset passes and patients receiving other rescue maneuvers.

Results

We included 271 patients. Successful recanalization was achieved in 76.4 %. Device-related complications occurred in 9.2 % of which 2.2 % were clinically significant. PH I, PH II, focal SAH, and diffuse SAH was observed in 5.2, 4.8, 12.2, and 2.2 %, respectively. A total of 39.5 % of patients had favorable clinical outcome. Considering treatments with >3 pREset passes or other rescue procedures, an additional 8.5 and 9.3 % of target vessels were recanalized. The chance of favorable clinical outcome decreased significantly with any kind of rescue therapy. In addition, the rate of PH I was significantly higher in patients treated with >3 pREset passes, whereas all other types of hemorrhage showed no difference.

Conclusion

In terms of safety and effectiveness, pREset performed comparably to other stent retriever devices. To avoid futile recanalization and potential additional harm, escalation of therapy beyond three thrombectomy passes should only be performed after careful individual consideration of each case.