Histiocytic erythema multiforme

Erythema multiforme is histologically characterized by liquefactive degeneration along the dermal-epidermal junction, necrotic keratinocytes and a lymphocytic infiltrate. We report a 10-year-old boy with recurrent erythema multiforme major of undetermined etiology with unusual histologic findings. A skin biopsy taken at day 2 of his eruption revealed histologic features otherwise characteristic of erythema multiforme, but mediated instead by a CD68-positive infiltrate, resembling cutaneous Kikuchi's disease. To the best of our knowledge this is the first reported case of 'histiocytic' erythema multiforme.     

A comparative study of attachment of human, bovine and mouse blastocysts to uterine epithelial monolayer

The in-vitro attachment of human, bovine and murine blastocyststo monolayer cultures of uterine epithelium were studied bytransmission electron microscopy. The human trophoblastic cellsintrude between uterine epithelial cells forming a multilayerduring attachment in vitro, thus resembling the intrusive typeof penetration observed in vivo. The bovine trophoblastic outgrowthresembled an epithelio-chorial attachment as the trophoblastformed an attachment plate on top of the endometrial cells withoutpenetration. In the murine attachment study, the trophoblastcells immediately displaced the uterine cells and formed contactwith the culture vessel.     

Inhibition of diabetes-associated complications by nucleophilic compounds

Mono- and diaminoguanidine inhibited ambient glucose-induced glycosylated end product formation of albumin and collagen 125I-labeled albumin covalent binding in vitro. Diaminoguanidine was a stronger inhibitor than monoaminoguanidine. These compounds also inhibited rat eye lens aldose reductase activity in vitro noncompetitively with respect to NADPH with Ki = 30.6 mM for monoaminoguanidine and Ki = 12.5 mM for diaminoguanidine. When administered daily for 98 days at a dose of 25 mg/kg body wt i.p., both compounds lowered eye lens sorbitol and aldose reductase activity in normoglycemic and alloxan-induced diabetic rats. Again, diaminoguanidine was a better inhibitor. Daily long-term administration of mono- and diaminoguanidine (25 mg/kg body wt i.p.) inhibited and prevented experimental diabetes-induced lens opacity in rats, respectively. It appears that diaminoguanidine has a better therapeutic potential in controlling diabetic complications.     

Changes in regional cerebral blood flow caused by deep-brain stimulation of the subthalamic nucleus in Parkinson's disease.

The aim of this study was to investigate the effect of deep-brain stimulation of the subthalamic nucleus (STN) on regional cerebral blood flow (rCBF) throughout the entire brain volume in patients with Parkinson's disease and to evaluate which of the brain areas showing an rCBF increase during STN stimulation related significantly to the improvement in motor function. METHODS: Ten consecutive Parkinson's disease patients (6 men, 4 women; mean age +/- SD, 59 +/- 8 y) with bilateral STN stimulators underwent 3 rCBF SPECT examinations at rest: the first preoperatively and the second and third postoperatively (follow-up, 4.8 +/- 1.4 mo) with STN stimulators on and off, respectively. The motor unified Parkinson's disease rating scale, the Hoehn and Yahr disability scale, and the Schwab and England activities-of-daily-living scale were used to evaluate the clinical state under each condition. Statistical parametric mapping was used to investigate rCBF during STN stimulation in comparison with rCBF preoperatively and with STN stimulators off. Also evaluated with statistical parametric mapping was the relationship between rCBF and individual motor scores used as covariates of interest. RESULTS: STN stimulation significantly changed rCBF in the right pre-supplementary motor area (pre-SMA), anterior cingulate cortex, and dorsolateral prefrontal cortex and in the medial Brodmann's area 8 (BA8) as defined in the atlas of Talairach and Tournoux (P < 0.05 corrected for multiple comparisons). The rCBF in these areas increased from the preoperative condition to the stimulators-on condition and decreased again after the stimulators were switched off. A significant correlation was detected between the improvement in motor scores and the rCBF increase only in the right pre-SMA and in the anterior cingulate motor area (P < 0.005, uncorrected). CONCLUSION: According to the topographic organization of the primate STN, our study shows that stimulation of the STN leads to rCBF increases in the motor (pre-SMA), associative, and limbic territories (anterior cingulate) in the frontal cortex. The significant correlation between motor improvement and rCBF increase in the pre-SMA and the anterior cingulate motor area reinforces the hypothesis that STN stimulation in parkinsonian patients can potentiate the cortical areas participating in higher-order aspects of motor control.     

Clinical Forum

The Clinical Forum Department presents brief reports focused on discussion of clinical issues or innovative practice ideas and programs.     

PEI-alginate nanocomposites as efficient in vitro gene transfection agents.

The positive charge on PEI was partially shielded by forming ionic nanocomposites with a polysaccharide, alginic acid, in aqueous solution, bypassing tedious chemical synthesis. The content of alginic acid was varied systematically to obtain a series of nanocomposites. The nanocomposites were first characterized by assessing the surface charge (zeta potential), size (DLS) and morphology (AFM) followed by evaluation for their DNA interaction ability, cytotoxicity and transfection efficiency on various cell lines. The transfection efficiency of PEI-alginate (6.26%) nanocomposites improved dramatically (2-16-fold over native PEI) in all the cell lines studied. However, a decrease in transfection efficiency was observed on deviating from this optimal concentration of alginic acid in nanocomposites. Cytotoxicity of PEI-alginate/DNA complexes was nearly abolished on increasing the concentration of alginic acid in nanocomposites. PEI-alginate (6.26%) nanocomposites also delivered SiRNAs efficiently into mammalian cells, resulting in 80% suppression of GFP expression. The cellular uptake and endosomal escape of PEI-alginate nanocomposites and PEI were found to follow a similar route when transfection was carried out in presence of chloroquine, bafilomycin A1, cytochalasin B and methyl-beta-cyclodextrin. The results demonstrate a versatile vector that can be used for efficient cytoplasmic delivery of a broad range of nucleic acids.