On the Changes of Extractive Amino Acid Contents in the Infected Purple Laver (Red Alga Porphyra)

The diseases of purple laver (red alga Porphyra) can be conveniently assorted into two types, one is the disease caused by parasitic microorganisms such as fungi or bacteria, the another is caused by physical, chemical or physiological damages. The pythium disease is well known as a typical example of the former, and for the latter shot hole and tumor are included. Besides these diseases, whose causes are comparatively well established, white blight and white rot have been recognized as popular ones characterized by the appearance of decolorized cell or cells especially in the marginal regions of the fronds. It is believed that these diseases develop on unhealthy fronds after being exposed to such unfavorable conditions as the deficiency of light quantities, low salinity of sea water and unsufficient daily exposure in the air. Several descriptions have been published on the environments and frond conditions when the symptoms of those diseases begin to be visible, however, little knowledge has yet been obtained about their causes and about the changes of chemical components in the cells during the development of the diseases. The purpose of the present study is to elucidate the physiological changes in the cells when thalli were infected by white rot. The authors reported here the differences in the contents of extractive amino acids and nitrogen, extractive and total, between the infected and the healthy fronds. The results can be summarized as follows: 1) When infected with white rot, such extractive amino acids decreased conspicuously as aspartic acid, glutamic acid, alanine and taurine contained in purple laver grown at the culture field. 2) On the contrary, it was observed that the contents of glycine and citrulline stayed almost unchanged or rather increased. 3) Purple lavers were cultured at different salinities of sea water in concrete tanks for about a week. The low salinity induced both the decrease of dominant extractive amino acids and the increase of unhealthy cells. 4) Little differences were observed in the contents of the extractive amino acids among the samples cultured at varied periods of daily exposure in the air. 5) No close relations were detected between the degrees of disease and the contents of extractive basic amino acids such as lysine, histidine and arginine. 6) The contents of extractive and total nitrogen, and ammonia changed irrespectively to the degrees of disease of the fronds

Identification and characterization of a fluorescent flagellar protein from the brown alga Scytosiphon lomentaria (Scytosiphonales, Phaeophyceae): A flavoprotein homologous to Old Yellow Enzyme

The posterior flagellum of the zoospore of the brown alga Scytosiphon lomentaria exhibits bright green autofluorescence. To identify the fluorescent flagellar substance(s), we isolated flagella from zoospores and partially purified a flavoprotein by anion-exchange and gel-filtration chromatography. Spectrofluorometric and chromatographic analyses showed that the flavoprotein had an apparent molecular mass of 41 kDa and a non-covalently bound flavin mononucleotide as a chromophore. Based on partial amino acid sequences of the protein, a cDNA of the 41-kDa flavoprotein was cloned and sequenced. The deduced amino acid sequence of the cDNA was homologous to that of the Old Yellow Enzyme family distributed in proteobacteria, yeasts and vascular plants

Pachychoroid neovasculopathy and age-related macular degeneration.

Pachychoroid neovasculopathy is a recently proposed clinical entity of choroidal neovascularization (CNV). As it often masquerades as neovascular age-related macular degeneration (AMD), it is currently controversial whether pachychoroid neovasculopathy should be distinguished from neovascular AMD. This is because its characteristics have yet to be well described. To estimate the relative prevalence of pachychoroid neovasculopathy in comparison with neovascular AMD and to investigate the phenotypic/genetic differences of the two diseases, we evaluated 200 consecutive Japanese patients who agreed to participate in the genetic study and diagnosed with pachychoroid neovasculopathy or neovascular AMD. Pachychoroid neovasculopathy was observed in 39 individuals (19. 5%), which corresponds to one fourth of neovascular AMD. Patients with pachychoroid neovasculopathy were significantly younger (p = 5. 1 × 10[−5]) and showed a greater subfoveal choroidal thickness (p = 3. 4 × 10[−14]). Their genetic susceptibility to AMD was significantly lower than that of neovascular AMD; ARMS2 rs10490924 (p = 0. 029), CFH rs800292 (p = 0. 013) and genetic risk score calculated from 11 AMD susceptibility genes (p = 3.8 × 10[−3]). Current results implicate that the etiologies of the two conditions must be different. Thus, it will be necessary to distinguish these two conditions in future studie

Disorganization of Semantic Brain Networks in Schizophrenia Revealed by fMRI

OBJECTIVES: Schizophrenia is a mental illness that presents with thought disorders including delusions and disorganized speech. Thought disorders have been regarded as a consequence of the loosening of associations between semantic concepts since the term "schizophrenia" was first coined by Bleuler. However, a mechanistic account of this cardinal disturbance in terms of functional dysconnection has been lacking. To evaluate how aberrant semantic connections are expressed through brain activity, we characterized large-scale network structures of concept representations using functional magnetic resonance imaging (fMRI). STUDY DESIGN: We quantified various concept representations in patients' brains from fMRI activity evoked by movie scenes using encoding modeling. We then constructed semantic brain networks by evaluating the similarity of these semantic representations and conducted graph theory-based network analyses. STUDY RESULTS: Neurotypical networks had small-world properties similar to those of natural languages, suggesting small-worldness as a universal property in semantic knowledge networks. Conversely, small-worldness was significantly reduced in networks of schizophrenia patients and was correlated with psychological measures of delusions. Patients' semantic networks were partitioned into more distinct categories and had more random within-category structures than those of controls. CONCLUSIONS: The differences in conceptual representations manifest altered semantic clustering and associative intrusions that underlie thought disorders. This is the first study to provide pathophysiological evidence for the loosening of associations as reflected in randomization of semantic networks in schizophrenia. Our method provides a promising approach for understanding the neural basis of altered or creative inner experiences of individuals with mental illness or exceptional abilities, respectively