Acute infarct of the corpus callosum presenting as alien hand syndrome: evidence of diffusion weighted imaging and magnetic resonance angiography

<p>Abstract</p> <p>Background</p> <p>Infarcts of the corpus callosum are rare and have not been well documented previously. As for a variety of signs and symptoms presented, alien hand syndrome (AHS) can be easily overlooked.</p> <p>Case presentation</p> <p>In this report, we present a patient with a mixed types of AHS coexistence secondary to the corpus callosum infarction, including a motor type of AHS by intermanual conflict (callosal type AHS) and a sensory type of AHS by alien hand and left hemianesthesia (posterior AHS).</p> <p>Conclusions</p> <p>Our case may contribute to the early recognition of AHS and to explore the abnormal neural mechanism of AHS. To our knowledge, rare reports have ever documented such mixed AHS coexisting secondary to the callosal lesion, based on advanced neuroimaging methods as in our case.</p

Conformation Effects of CpG Methylation on Single-Stranded DNA Oligonucleotides: Analysis of the Opioid Peptide Dynorphin-Coding Sequences

Single-stranded DNA (ssDNA) is characterized by high conformational flexibility that allows these molecules to adopt a variety of conformations. Here we used native polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy to show that cytosine methylation at CpG sites affects the conformational flexibility of short ssDNA molecules. The CpG containing 37-nucleotide PDYN (prodynorphin) fragments were used as model molecules. The presence of secondary DNA structures was evident from differences in oligonucleotide mobilities on PAGE, from CD spectra, and from formation of A-T, G-C, and non-canonical G-T base pairs observed by NMR spectroscopy. The oligonucleotides displayed secondary structures at 4°C, and some also at 37°C. Methylation at CpG sites prompted sequence-dependent formation of novel conformations, or shifted the equilibrium between different existing ssDNA conformations. The effects of methylation on gel mobility and base pairing were comparable in strength to the effects induced by point mutations in the DNA sequences. The conformational effects of methylation may be relevant for epigenetic regulatory events in a chromatin context, including DNA-protein or DNA-DNA recognition in the course of gene transcription, and DNA replication and recombination when double-stranded DNA is unwinded to ssDNA

MR imaging of the corpus callosum.

The corpus callosum is the major axonal commissure of the brain, connecting the two cerebral hemispheres and providing communication between the cortical and subcortical neurons. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. We review the normal anatomy, development, and process of myelination of the corpus callosum. The MR features of various pathologic conditions involving the corpus callosum are described. Finally, we discuss the evolving role of MR imaging in neuropsychiatric diseases with respect to the corpus callosum

MR imaging of the corpus callosum.

The corpus callosum is the major axonal commissure of the brain, connecting the two cerebral hemispheres and providing communication between the cortical and subcortical neurons. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. We review the normal anatomy, development, and process of myelination of the corpus callosum. The MR features of various pathologic conditions involving the corpus callosum are described. Finally, we discuss the evolving role of MR imaging in neuropsychiatric diseases with respect to the corpus callosum

Percutaneous real-time ultrasound-guided renal biopsy performed solely by nephrologists: A case series

Renal biopsy is an integral part of the nephrologists’ diagnostic armamentarium. Usually it is performed by radiologists or nephrologists with radiologist’s assistance. Our aim was to assess the efficacy and safety of percutaneous ultrasound-guided renal biopsy performed solely by nephrologists. We performed real-time ultrasound-guided renal biopsy on 37 patients (N group). The results were then compared with those of a similar number of biopsies done with radiologist’s support (NR group) immediately prior to these. In the N group, 36 biopsies (97.3%) were successful and were histopathologically adequate, whereas in the NR group, all biopsies were successful but only 28 were adequate (75.68%). Eighteen patients required only a single attempt in the N group, whereas majority (34 patients) in the NR group required two or more attempts. The average attempt per bit of renal tissue was 1.22 in both the groups. The average number of passes per patient was 1.77 in the N group and 2.32 in the NR group. The mean size of renal tissue obtained was 1.41 ± 0.47 cm in the N group and 1.19 ± 0.42 cm in the NR group. The average number of glomeruli was 15.62 ± 5.26 and 13.7 ± 7.38 in the N and NR groups, respectively (P<0.05). In the N group, there were no complications except two cases of post procedural hematuria that was managed conservatively. There was no need for blood transfusion and both of them were discharged after 48 hours. No patient had peri-renal collection or hematoma on repeat ultrasonography of the abdomen at 24 hours. However, in the NR group, five patients developed complications and one patient required laparotomy. Our study shows that percutaneous ultrasound-guided renal biopsy can be safely and successfully performed entirely by nephrologists without outside assistance. In our series, nephrologists who performed solely took fewer attempts, had better yield and fewer complications when compared to biopsies performed with radiologist’s assistance. More and more nephrologists should take up this simple yet vital procedure