3‐[(2,4‐dimethoxy)benzylidene]‐anabaseine dihydrochloride protects against 6‐hydroxydopamine‐induced parkinsonian neurodegeneration through α7 nicotinic acetylcholine receptor stimulation in rats

To explore a novel therapy against Parkinson's disease through enhancement of α7 nicotinic acetylcholine receptor (nAChR), we evaluated the neuroprotective effects of 3‐[(2,4‐dimethoxy)benzylidene]‐anabaseine dihydrochloride (DMXBA; GTS‐21), a functionally selective α7 nAChR agonist, in a rat 6‐hydroxydopamine (6‐OHDA)‐induced hemiparkinsonian model. Microinjection of 6‐OHDA into the nigrostriatal pathway of rats destroys dopaminergic neurons selectively. DMXBA dose dependently inhibited methamphetamine‐stimulated rotational behavior and dopaminergic neuronal loss induced by 6‐OHDA. The protective effects were abolished by methyllycaconitine citrate salt hydrate, an α7 nAChR antagonist. Immunohistochemical study confirmed abundant α7 nAChR expression in the cytoplasm of dopaminergic neurons. These results indicate that DMXBA prevented 6‐OHDA‐induced dopaminergic neuronal loss through stimulating α7 nAChR in dopaminergic neurons. Injection of 6‐OHDA elevated immunoreactivities to glial markers such as ionized calcium binding adaptor molecule 1, CD68, and glial fibrillary acidic protein in the substantia nigra pars compacta of rats. In contrast, these immunoreactivities were markedly inhibited by comicroinjection of DMXBA. Microglia also expressed α7 nAChR in both resting and activated states. Hence, we hypothesize that DMXBA simultaneously affects microglia and dopaminergic neurons and that both actions lead to dopaminergic neuroprotection. The findings that DMXBA attenuates 6‐OHDA‐induced dopaminergic neurodegeneration and glial activation in a rat model of Parkinson's disease raisethe possibility that DMXBA could be a novel therapeutic compound to prevent Parkinson's disease development. © 2012 Wiley Periodicals, Inc.     

Zigzag gas phases on holey adsorbed layers

We report for the first time a zigzag-shaped gas phase at a highly-ordered pyrolytic graphite/water interface. The novel shape of the gaseous domain is triggered by the holes of the underlying solid-like layers, which are composed of air molecules. Specifically, many holes were created by heating in the thin solid-like layers, which roughened them. The gas domains that formed on these layers deformed from circular to zigzag-shaped as the contact lines expanded while avoiding the holes of the underlying layers. We explained the formation and growth processes of these gas structures in terms of thin film growth, which varies with the mobility of the constituent molecules.

Heating induces the formation of novel zigzag gas phases on the holey adsorbed air layers.     

Clinical features of patients with pars defects identified in adulthood

Purpose

Lumbar spondylolysis is considered a stress fracture of the pars interarticularis that occurs during growth. However, it is sometimes insidious and identified in adults as pseudoarthrosis, the terminal-stage of spondylolysis. The purpose of this study was to identify the clinical features of patients with terminal-stage spondylolysis that first manifested during adulthood.

Patients and methods

Thirty-six patients (21 men, 15 women; mean age 55.8 years; age range 25–77 years) with low back pain (LBP) were studied. In all patients, lumbar spondylolysis had not been diagnosed until the first visit to our hospital. Patient data collected were history of athletic activity and LBP during their growth period and radiological findings, such as spinal level, displacement, and spina bifida occulta (SBO).

Results

Among the 36 patients, including a patient with multi-level spondylolysis (L4 and L5), a total of 37 vertebrae with terminal-stage spondylolysis were identified. Twenty-three (89.2 %) of the 37 vertebrae had L5 spondylolysis. Sixteen patients (44.4 %) had no history of athletic activity, 26 (72.2 %) had no experience of LBP during their growth period, and 14 (38.9 %) had neither. Twenty of the 37 vertebrae (70.4 %) involved displacement (grade 1 = 14; grade 2 = 6). In nine patients (25.0 %; eight men, one woman), SBO of the sacrum was accompanied by L5 spondylolysis.

Conclusions

Approximately 90 % of patients with terminal-stage spondylolysis that was first diagnosed in adulthood involved the L5. Also, about 40 % had no history of athletic activity or experience of LBP during their growth period. In addition, only some patients with L5 spondylolysis had SBO, and all but one of these patients was male. This suggests that male patients with L5 spondylolysis may have some congenital predisposition.

     

Recent advances in fluorescent labeling techniques for fluorescence microscopy

Tremendous progress in recent computer-controlled systems for fluorescence and laser-confocal microscopy has provided us with powerful tools to visualize and analyze molecular events in the cells. Various fluorescent staining and labeling techniques have also been developed to be used with these powerful instruments. Fluorescent proteins such as green fluorescent protein (GFP) allow us to directly label particular proteins of interest in living cells. This technique has been extended over a large area of cell biology, and a variety of fluorescent protein-derived techniques have been developed to visualize the functions and conditions of the molecules within living cells. In this review, we summarize the techniques for fluorescent staining and labeling for recent fluorescence microscopy.     

Relationship between chewing ability and 4-year mortality in a cohort of 80-year-old Japanese people

OBJECTIVE: Poor oral health has been reported to be a risk indicator of mortality, however, few data are available regarding the relationship between chewing ability and mortality. We examined the relationship between self-assessed chewing ability and mortality in elderly subjects. DESIGN: Prospective study. SUBJECTS AND METHODS: Participating in the study were 697 people (277 males, 420 females) from 1282 individuals (80 years old) residing in Fukuoka Prefecture, Japan. Data on oral and systemic health status through questionnaires, accompanied by physical and laboratory blood examinations were obtained. Chewing ability was assessed based on the number of types of food each subject reported as able to chew by questionnaire. RESULTS: A total of 108 subjects died between 1998 and 2002. Those with the lowest number of chewable foods were associated with higher risk of mortality than those with the ability to chew all of the 15 types of food surveyed [hazard ratio (HR) = 2.38, 95% confidence interval (95% CI) = 1.07-5.29], though other parameters including current smoking, low serum albumin, and poor physical health status were more significant. Further, reduced chewing ability of soft foods increased the risk (HR = 2.65, 95% CI = 1.20-5.87). CONCLUSION: Chewing ability was associated with mortality in a population of 80-year-old community residents, and may be a predictor for survival rate.     

Glucosamine enhances platelet-derived growth factor-induced DNA synthesis via phosphatidylinositol 3-kinase pathway in rat aortic smooth muscle cells

Vascular smooth muscle cells play a key role in the development of atherosclerosis. Culture of vascular smooth muscle A10 cells with high glucose for 4 weeks enhanced platelet-derived growth factor (PDGF)-induced BrdU incorporation. Since a long period of high glucose incubation was required for the effect, and it was inhibited by co-incubation with azaserine, the role of hexosamine biosynthesis in the development of atherosclerosis in diabetes was studied in A10 cells. Addition of glucosamine to the culture media enhanced PDGF-stimulated BrdU incorporation, and PDGF-induced tyrosine phosphorylation of the PDGF beta-receptor was increased by glucosamine treatment. Of the subsequent intracellular signaling pathways, PDGF-induced PDGF beta-receptor association with PLC gamma was not affected, whereas tyrosine phosphorylation of Shc, subsequent association of Shc with Grb2, and MAP kinase activation were relatively decreased. In contrast, PDGF-induced PDGF beta-receptor association with the p85 regulatory subunit of PI3-kinase and PI3-kinase activation were increased by 20% (P<0.01) and 36% (P<0.01), respectively. The intracellular signaling molecules responsible for the glucosamine effect were further examined using pharmacological inhibitors. Pretreatment with PLC inhibitor (U73122) had negligible effects, and MEK1 inhibitor (PD98059) showed only a slight inhibitory effect on the PDGF-induced BrdU incorporation. In contrast, pretreatment with PI3-kinase inhibitor (LY294002) significantly inhibited glucosamine enhancement of PDGF-induced BrdU incorporation. These findings suggest that glucosamine is involved in the development of atherosclerosis by enhancing PDGF-induced mitogenesis specifically via the PI3-kinase pathway.     

Piecemeal degranulation of mast cells in the inflammatory eyelid lesions of interleukin-4 transgenic mice. Evidence of mast cell histamine release in vivo by diamine oxidase-gold enzyme-affinity ultrastructural cytochemistry

We used light and electron microscopy to analyze the eyelid inflammation that develops in transgenic mice that overexpress interleukin-4 (IL-4; Tepper et al, Cell 62:457, 1990). Analysis of alkaline Giemsa-stained plastic sections examined by light microscopy (Dvorak et al, J Exp Med 132:558, 1970), as well as by routine transmission electron microscopy, indicated that the mast cells in the inflammatory eyelid lesions were undergoing piecemeal degranulation, a form of secretion in which the cells' cytoplasmic granules exhibit characteristic morphologic changes that are thought to be associated with the prolonged, vesicle-mediated release of the granules' constituents. Moreover, by using a newly reported enzyme affinity-gold method, which stains histamine based on binding to diamine oxidase-gold (Dvorak et al, J Histochem Cytochem 41:787, 1993), we show that these activated mast cells had released much of their histamine content. The eyelid lesions also exhibited increased numbers of mast cells; interstitial fibrosis, particularly around cutaneous nerves and blood vessels; activated fibroblasts; focal axonal damage; venules with endothelial cells containing numerous vesiculo-vacuolar organelles; and infiltrates of neutrophils and eosinophils. Our findings illustrate that overexpression of the IL-4 gene in vivo can result in eyelid lesions associated with piecemeal degranulation of mast cells, as well as tissue fibrosis and a variety of other pathologic changes. These results also represent the first direct morphologic evidence for histamine secretion by mast cells in vivo.