Cognitive impairments associated with morphological changes in cortical and subcortical structures in multiple system atrophy of the cerebellar type.

BACKGROUND AND PURPOSE: Patients with the cerebellar variant of multiple system atrophy (MSA-C) often show cognitive deficits in various cognitive domains. The association between morphometric changes in cortical and subcortical structures and cognitive impairments in MSA-C were investigated to explore the neural correlates responsible for cognitive deficits in MSA-C patients. METHODS: Using surface-based morphometry, region-of-interest cortical thickness and the volumes and shapes of subcortical structures were examined in 18 patients who fulfilled the criteria of probable MSA-C and were compared to 50 healthy controls. The association between regional changes and cognitive functions in MSA-C were investigated by applying linear regression analyses after controlling for confounding factors. RESULTS: Compared with controls, the patients with MSA-C showed significant cortical thinning in the fronto-temporo-parietal regions and volume reduction in subcortical structures with shape changes. Cerebellar volume had no significant effect on cortical and subcortical volumes. The severity of atrophic changes in the bilateral thalamus, the left cerebellum and the left pericalcarine gyrus were significantly correlated with attentional, executive and visuospatial dysfunctions. CONCLUSION: Cognitive impairment in MSA-C might result from functional disruption of the corticostriatal and pontocerebellar circuit mediated by primary cortical, cerebellar or thalamic pathology.

Structural correlations between dermoscopic and histopathological features of juvenile xanthogranuloma.

Juvenile xanthogranuloma(JXG) is the variant of non-Langerhans' cell histiocytosis. The orange-yellow background coloration with clouds of paler yellow deposits is the most characteristic dermoscopic finding of JXG. Other dermoscopic features include erythematous border, subtle pigment network and white linear streak. The objective of this study was to present the structural correlation between dermoscopic features and histopathological findings of JXG and to find the different dermoscopic features in various stages of JXG. Eleven patients with histologically proven JXG were examined with polarized light dermoscopy. Histopathological findings were assessed and dermoscopic features including setting sun appearance, clouds of paler yellow globules, whitish streak, and branched and linear vessels were evaluated. Among 11 patients, five patients were in early evolutionary stage, four patients in fully developed stage and two in late regressive stage. The setting sun appearance was found in all patients in different stages except one in late regressive stage (90.9%). The clouds of paler yellow globules were present in nine patients (81.8%) and were constant features in fully developed stage and late regressive stage. The whitish streak was present in four patients (36.4%) and telangiectasia in 10 patients (81.8%). The setting sun appearance may hold diagnostic value in early evolutionary stage to fully developed stage, but not in late regressive stage. The clouds of paler yellow globules are more predominant in fully developed stage and late regressive stage. In addition to the use of dermoscopy as an accurate diagnostic tool for differential diagnosis, it could be applied in evaluation of histopathological maturation of JXG.

Changing etiology of community-acquired bacterial meningitis in adults: a nationwide multicenter study in Korea.

Epidemiologic data on the etiologic organisms is important for appropriate empirical antibiotic treatment of bacterial meningitis. We identified the etiologies of community-acquired bacterial meningitis in Korean adults and the associated epidemiological factors. A retrospective, multicenter nationwide study was carried out. Patients 18 years of age or older with community-acquired bacterial meningitis with a confirmed pathogen were enrolled. Demographic, clinical, and microbiological data were collected. One hundred and ninety-five cases were collected. Streptococcus pneumoniae was the most common pathogen (50.8%), followed by Staphylococcus aureus (10.3%), Klebsiella pneumoniae (7.7%), Listeria monocytogenes (6.7%), and group B Streptococcus (3.1%). The penicillin resistance rate of the S. pneumoniae was 60.3%; 40.0% of the organisms were not susceptible to third-generation cephalosporins. The combination of third-generation cephalosporin with vancomycin was used in 76.3% of cases. Steroids were given before or with the first dose of antibiotics in 37.4% of patients. The 30-day mortality rate was 20.5% and neurological sequelae developed in 15.6% of cases. S. pneumoniae was the most common organism identified in community-acquired bacterial meningitis among Korean adults. S. aureus, K. pneumoniae, L. monocytogenes, and group B Streptococcus were also common. S. pneumoniae had high rates of resistance to penicillin and third-generation cephalosporins.

Dermoscopic features of Bowen's disease in Asians.

BACKGROUND: Previously, dermoscopic features of Bowen's disease (BD) were extensively investigated in two studies, but there were some discrepancies. The dispute necessitated a further study concerning the dermoscopic features of BD. OBJECTIVE: To describe the dermoscopic features of BD in Asians and to assess dermoscopy as a post-treatment monitoring tool of BD. MATERIALS AND METHODS: Dermoscopic examinations of histopathologically diagnosed 26 BD lesions were performed to evaluate for the presence of various dermoscopic features. In addition, the correlating changes of dermoscopic features and histopathological results before and after treatments were assessed in five patients with BD. RESULTS: Dermoscopically, 10 lesions were pigmented and 16 lesions were non-pigmented. The most frequent dermoscopic findings of BD were vascular structures (96%) and a scaly surface (96%). Among vascular structure, glomerular vessels were most frequently observed (77%). The other vascular structures in our study were linear irregular vessels, dotted vessels, polymorphous/atypical vessels and arborizing vessels. Among five patients who had been treated with either photodynamic therapy or 5% imiquimod cream, four patients revealed disappearance of dermoscopic vascular structures, but one patient showed remaining vascular structures after treatment. Skin biopsy from treated lesions disclosed clearance of BD in four patients who had no vascular structures but remaining BD in the patient whose dermoscopic finding displayed no disappearance of vascular structures. CONCLUSIONS: Vascular structures, especially glomerular vessels plus a scaly surface, were common dermoscopic findings of BD in Asians. In addition, existence of dermoscopic vascular structures after treatment appears to be associated with residual disease.

Podocyte biology in diabetic nephropathy.

Glomerular visceral epithelial cells, namely podocytes, are highly specialized cells and give rise to primary processes, secondary processes, and finally foot processes. The foot processes of neighboring podocytes interdigitate, leaving between them filtration slits. These are bridged by an extracellular substance, known as the slit diaphragm, which plays a major role in establishing size-selective barrier to protein loss. Furthermore, podocytes are known to synthesize matrix molecules to the glomerular basement membrane (GBM), including type IV collagen, laminin, entactin, and agrin. Because diabetic nephropathy is clinically characterized by proteinuria and pathologically by glomerular hypertrophy and GBM thickening with foot process effacement, podocytes have been the focus in the field of research on diabetic nephropathy. As a result, many investigations have demonstrated that the diabetic milieu per se, hemodynamic changes, and local growth factors such as transforming growth factor-beta and angiotensin II, which are considered mediators in the pathogenesis of diabetic nephropathy, induce directly and/or indirectly hypertrophy, apoptosis, and structural changes, and increase type IV collagen synthesis in podocytes. This review explores some of the structural and functional changes of podocytes under diabetic conditions and their role in the development and progression of diabetic nephropathy.

A new antioxidant monoterpene glycoside, alpha-benzoyloxypaeoniflorin from Paeonia suffruticosa.

Alpha-benzoyloxypaeoniflorin (1), a new antioxidant monoterpene alpha-glycoside anomer was isolated from Paeonia suffruticosa along with known compounds, beta-benzoyloxypaeoniflorin (2), paeonolide, paeoniflorin and mudanpioside H. The structure of 1 has been determined by comparing spectral data with those of beta-benzoyloxypaeoniflorin (2). Compound 1 exhibited moderately potent radical scavenging activity on DPPH radical.

Recanalization with Wingspan stent for acute middle cerebral artery occlusion in failure or contraindication to intravenous thrombolysis: a feasibility study.

BACKGROUND AND PURPOSE: Recanalization with the Wingspan stent, which can be deployed rapidly and safely, is an option for treating acute ischemic stroke when intravenous thrombolysis has failed or is contraindicated. This study was performed to evaluate feasibility, efficacy, and safety of recanalization for acute middle cerebral artery occlusion using the Wingspan stent. MATERIALS AND METHODS: We collected 10 patients with acute MCA occlusion in whom recanalization was not achieved with a standard intravenous thrombolysis, or who were ineligible for intravenous thrombolysis, or who presented after 3 hours of symptom onset and in whom the stent placement could be completed within 8 hours from symptom onset. We analyzed angiographic and clinical results. RESULTS: Successful recanalization with the Wingspan stent was achieved in all patients. The mean NIHSS score on admission was 12.7 points (range 4-21). The occlusion sites were located in the 1st segment (n = 7; 2 left, 5 right) and 2nd segment (n = 3, all right) of the MCA. The mean time interval from stroke symptom onset to stent placement was 344.8 ± 76.3 minutes. No intracranial hemorrhage, vessel perforations, or dissections occurred in any patient. Nine patients improved on the NIHSS at 7 days. One patient did not have a change in the NIHSS score, even though the occluded artery was completely recanalized. At 7 days, the NIHSS score of all patients was 4.4 ± 4.7 (median 4, range 0-13). At discharge, an mRS of ≤ 3 was achieved in all patients and an mRS of ≤ 2 was achieved in 7 patients (70%). CONCLUSIONS: This small case series demonstrates the feasibility of using the Wingspan stent safely and effectively for MCA occlusions when standard treatments are ineffective or not available.

Air-stable silver-coated copper particles of sub-micrometer size.

Silver-coated copper particles with various silver loading were prepared by a direct liquid-to-particle conversion process in spray pyrolysis reactor system. The prepared particles were completely densified at 900°C within a residence time of 2.1 s and had core-shell structure, of which formation mechanism was proposed. The mean diameter of particles was 0.45 µm. Copper particles of 20 wt.% of silver loading were stable under air and 95% of copper remained as metallic copper even after 1 month of exposure to air. This enhanced air-stability contributed to the enhanced electrical property of conductive film obtained from the coated particles. The conductive film obtained from 15 wt.% of silver-coated copper particles had a sheet resistance of 1.2 mΩ square(-1). This low resistance resulted from the lack of oxide layer and low sintering temperature of silver layer.

Electrical and morphological properties of conducting layers formed from the silver-glass composite conducting powders prepared by spray pyrolysis.

Ag-glass composite powders with various glass contents and excellent conducting properties were prepared by spray pyrolysis. Irrespective of the glass content, all the prepared powders were found to comprise spherical particles with nonaggregation characteristics. The crystal structure of the powder particles resembled that of pure Ag particles, irrespective of the glass content. Conducting layers formed from pure Ag did not melt even when sintered at 400 degrees C. On the other hand, conducting layers formed from composite powders containing 3 and 5 wt% glass melted when sintered at 400 degrees C. The optimum glass content of the composite powders was 3 wt% at sintering temperatures of 400 and 450 degrees C. However, the optimum glass content decreased to 1 wt% when the sintering temperature was increased to 550 degrees C. The lowest specific resistances of the conducting layers formed from the composite powders were 5.3 and 2.3 microohms-cm at sintering temperatures of 400 and 550 degrees C, respectively.

Attentional distractibility by optokinetic stimulation in Alzheimer disease.

OBJECTIVE: Unilateral temporoparietal injury may result in an attentional deficit for stimuli presented in contralesional space. Thus, bilateral temporoparietal degeneration associated with Alzheimer disease (AD) might result in a bilateral attentional disturbance. Tests for hemispatial neglect, however, primarily assess spatial attentional asymmetries, and a bilateral attentional disorder might not be detected with these tests. The goal of this study was to learn whether optokinetic stimulation (OKS) would perturb the balanced attentional deficits of AD patients and alter their spatial allocation of attention. METHODS: In Experiment I, 10 AD patients with bilateral temporoparietal glucose hypometabolism on PET and 10 controls bisected lines in two conditions: stationary solid lines superimposed on a moving background and "striped lines" where the whole line was stationary but the stripes within the line moved. The background OKS or the stripes within the line moved leftward or rightward or were stationary. In Experiment II, to investigate whether the influence of background movements would increase with AD severity, we conducted a similar experiment in 56 patients with various stages of AD. RESULTS: In Experiment I, the line bisection errors (LBEs) of AD subjects, but not of the controls, were markedly influenced by both background and within line stripe motions, deviations occurring in the same direction of movement. In Experiment II, LBEs also occurred in the same direction as background movement and increased with dementia severity. CONCLUSIONS: These results demonstrate that patients with Alzheimer disease are spatially distracted by moving stimuli.

Activation of the renin-angiotensin system within podocytes in diabetes.

The autocrine and paracrine activation of the renin-angiotensin system (RAS) within cells of the kidney plays a role in the overall pathophysiology of the renal disease due to diabetes. In this study, we focus on components of the RAS in the podocyte as these cells are important in the pathogenesis of glomerulosclerosis and proteinuria. Immortalized mouse podocytes were exposed to media containing normal glucose (NG) or high glucose (HG) for in vitro studies. In vivo studies utilized kidney tissue obtained from rats treated for 3 months with streptozotocin to induce diabetes. Angiotensinogen (AGT) and the angiotensin II (AII) type 1 receptor mRNA and protein were significantly increased in the podocytes cultured under the high glucose conditions. Both angiotensins I and II levels were significantly higher in cell lysates and the conditioned media of cells grown in high glucose. There were no differences in renin activity, angiotensin-converting enzyme level, or AII type 2 receptor level. Glomerular AGT and AII type 1 receptor assessed by means of immunohistochemistry were increased in diabetic rats compared with the control rats. Other measured components of the RAS within the glomeruli were not different. We suggest that increased AGT, an attendant increase in AII and increased AII type 1 receptor in podocytes experiencing diabetic conditions play an important role in the pathogenesis of diabetic nephropathy.

Controlling Wine Malolactic Fermentation with Nisin and Nisin-Resistant Strains of Leuconostoc oenos.

The polypeptide nisin (100 U/ml) prevented malolactic fermentation in wines by indigenous or intentionally added lactic acid bacteria. Nisin (100 U/ml)-resistant mutants of Leuconostoc oenos were obtained and used with nisin in wine to carry out a pure-culture malolactic fermentation in the presence or absence of other lactic acid bacteria. Nisin degradation by mutants was not observed, and residual nisin was detectable in wines 4 months after it was added. Results indicated that nisin or nisin with resistant bacterial starter cultures can be used to control malolactic fermentation in wines.

Influence of fat and emulsifiers on the efficacy of nisin in inhibiting Listeria monocytogenes in fluid milk.

The recent FDA affirmation of nisin, an antimicrobial peptide, as a GRAS (generally recognized as safe) additive in pasteurized cheese spreads has renewed interest in its potential application in US dairy products. Fluid milks were prepared with varying concentrations of milk fat (0 to 12.9%) and of nisin (0 to 50 U/ml). Biological activity assays using a sensitive indicator microorganism in a well diffusion system indicated that initial nisin activity (50 U/ml) decreased by about 33% when it was added to skim milk and by more than 88% when added to milk containing 12.9% fat. Nisin activity decreased by ca. 50% in milk containing 1.29% fat. Milks containing 0, 10, or 50 U/ml of nisin and varying fat percentages were challenged with approximately log10 7 to 7.5 cfu/ml of log phase Listeria monocytogenes Scott A or Jalisco. At 2 h after inoculation, the viable count of L. monocytogenes Scott A decreased to log10 .30 cfu/ml in skim milk with 50 U/ml of nisin, decreased to log10 2.90 cfu/ml in skim milk with 10 U/ml of nisin, and increased slightly (log10 7.8 cfu/ml) in skim milk without nisin. In half-and-half (12.9% milk fat), nisin was far less effective in inhibiting Listeria with populations decreasing to log10 6.57 cfu/ml for 10 U/ml of nisin and log10 5.87 cfu/ml for 50 U/ml. Similar results were obtained with L. monocytogenes Jalisco. The nonionic emulsifier, Tween 80, partially counteracted decreases of nisin activity in milks, whereas the anionic emulsifier, lecithin, had no effect. Addition of Tween 80 significantly increased the activity of nisin against L. monocytogenes in milk regardless of fat content.

Do N-methyl-D-aspartate antagonists have disproportionately greater effects on brain swelling than on ischemic damage in focal cerebral infarction?

Using a frozen section technique, we have assessed the effects of N-methyl-D-aspartate (NMDA) antagonist upon brain swelling caused by ischemic brain edema in a rat model of focal cerebral infarction. Although pretreatment with the competitive NMDA antagonist, D-CPPene or the noncompetitive NMDA antagonist, CNS 1102 reduced both the volumes of infarction and ischemic edema in the cerebral hemisphere, mean reduction in brain edema was proportionately similar to decrease in infarct volume in the same animals (correlation coefficient, r = 0.82, p < 0.001). There was, therefore, no evidence of disproportionately greater effects with NMDA antagonist upon brain edema.

Bowtie and upbeat nystagmus evolving into hemi-seesaw nystagmus in medial medullary infarction: possible anatomic mechanisms.

A 20-year-old man with bilateral medial medullary infarction showed transition of bowtie and upbeat nystagmus into hemi-seesaw nystagmus. Follow-up MRI revealed near complete resolution of the right medullary lesion. This transition of nystagmus suggests that the upbeat nystagmus was generated by bilateral lesions in the ascending pathways from both anterior semicircular canals (SCC), and that the hemi-seesaw nystagmus was caused by damage to the pathway from the left anterior SCC.

Production of indoxyl derivatives in indole-supplemented tissue cultures of Polygonum tinctorium.

A red pigment produced in the suspension, root and, shoot cultures of Polygonum tinctorium Ait. (Polygonaceae) upon feeding of indole was identified as indirubin by comparison with the authentic compound obtained from the leaves of the plant. Indole-5-D was specifically incorporated into the pigment to form indirubin-5,5'-D(2) when fed to the cultures. Tryptophan feeding did not cause the accumulation of the pigment. The dilution of the fed indole with the endogeneous indole was about zero, ten, and thirty-five percent for the suspension, root, and shoot cultures, respectively. The feeding of indole to the suspension and root cultures suppressed the biosynthesis of indigo thus resulting in the production of indirubin. However, the fed indole was equally well incorporated into indigo and indirubin in the shoot culture.