Relationship Between Glycerolipids and Photosynthetic Components During Recovery of Thylakoid Membranes From Nitrogen Starvation-Induced Attenuation in Synechocystis sp. PCC 6803.

Thylakoid membranes, the site of photochemical and electron transport reactions of oxygenic photosynthesis, are composed of a myriad of proteins, cofactors including pigments, and glycerolipids. In the non-diazotrophic cyanobacterium Synechocystis sp. PCC 6803, the size and function of thylakoid membranes are reduced under nitrogen (N) starvation but are quickly recovered after N addition to the starved cells. To understand how the functionality of thylakoid membranes is adjusted in response to N status in Synechocystis sp. PCC 6803, we examined changes in thylakoid components and the photosynthetic activity during the N starvation and recovery processes. In N-starved cells, phycobilisome content, photosystem II protein levels and the photosynthetic activity substantially decreased as compared with those in N-sufficient cells. Although the content of chlorophyll (Chl) a, total protein and total glycerolipid also decreased under the N-starved condition based on OD730 reflecting cell density, when based on culture volume, the Chl a and total protein content remained almost constant and total glycerolipid content even increased during N starvation, suggesting that cellular levels of these components decrease under the N-starved condition mainly through dilution due to cell growth. With N addition, the photosynthetic activity quickly recovered, followed by full restoration of photosynthetic pigment and protein levels. The content of phosphatidylglycerol (PG), an essential lipid constituent of both photosystems, increased faster than that of Chl a, whereas the content of glycolipids, the main constituents of the thylakoid lipid bilayer, gradually recovered after N addition. The data indicate differential regulation of PG and glycolipids during the construction of the photosynthetic machinery and regeneration of thylakoid membranes. Of note, addition of PG to the growth medium slightly accelerated the Chl a accumulation in wild-type cells during the recovery process. Because PG is required for the biosynthesis of Chl a and the formation of functional photosystem complexes, rapid PG biosynthesis in response to N acquisition may be required for the rapid formation of the photosynthetic machinery during thylakoid regeneration.

Versatile allosteric molecular devices based on reversible formation of luminous lanthanide complexes.

A versatile molecular device (lanthanide-complex molecular beacon; LCMB) was prepared by tethering ethylenediaminetetraacetic acid to the 5'-end and 1,10-phenanthroline to the 3'-end of stem-loop structured DNA as metal-capturing and sensitizer moieties, respectively. The emission from LCMB responded to the target molecule through the reversible structural change.

Psychiatric disorders and clinical correlates of suicidal patients admitted to a psychiatric hospital in Tokyo.

BACKGROUND: Patients admitted to a psychiatric hospital with suicidal behavior (SB) are considered to be especially at high risk of suicide. However, the number of studies that have addressed this patient population remains insufficient compared to that of studies on suicidal patients in emergency or medical settings. The purpose of this study is to seek features of a sample of newly admitted suicidal psychiatric patients in a metropolitan area of Japan. METHOD: 155 suicidal patients consecutively admitted to a large psychiatric center during a 20-month period, admission styles of whom were mostly involuntary, were assessed using Structured Clinical Interviews for DSM-IV Axis I and II Disorders (SCID-I CV and SCID-II) and SB-related psychiatric measures. Associations of the psychiatric diagnoses and SB-related characteristics with gender and age were examined. RESULTS: The common DSM-IV axis I diagnoses were affective disorders 62%, anxiety disorders 56% and substance-related disorders 38%. 56% of the subjects were diagnosed as having borderline PD, and 87% of them, at least one type of personality disorder (PD). SB methods used prior to admission were self-cutting 41%, overdosing 32%, self-strangulation 15%, jumping from a height 12% and attempting traffic death 10%, the first two of which were frequent among young females. The median (range) of the total number of SBs in the lifetime history was 7 (1-141). Severity of depressive symptomatology, suicidal intent and other symptoms, proportions of the subjects who reported SB-preceding life events and life problems, and childhood and adolescent abuse were comparable to those of the previous studies conducted in medical or emergency service settings. Gender and age-relevant life-problems and life events were identified. CONCLUSIONS: Features of the studied sample were the high prevalence of affective disorders, anxiety disorders and borderline PD, a variety of SB methods used prior to admission and frequent SB repetition in the lifetime history. Gender and age appeared to have an influence on SB method selection and SB-preceding processes. The findings have important implications for assessment and treatment of psychiatric suicidal patients.

[Psychiatric and personality disorders and clinical characteristics of admitted suicidal patients: data from Matsuzawa Suicidal Behavior Study].

Psychiatric patients who have shown suicidal behavior (SB) are belived to be at a particularly high risk of suicide. However, the number of studies that have sought ways to prevent suicide in this patient population is limited. The present study investigated the diagnosis and SB-related characteristics of psychiatric inpatients showing suicidal behavior prior to admission. One-hundred and fifty-seven eligible subjects were recruited from patients consecutively admitted to a large psychiatric facility during a 20-month period in 2006 and 2007, and underwent extensive research interviews. Percentages of diagnoses based on the Structured Clinical Interview for DSM-IV, Clinician Version (SCID-I, CV) in this series were: affective disorders, 62%; anxiety disorders, 55%; substance use disorders, 38%; psychotic disorders, 27%; and eating disorders, 10%. Eighty-seven percent of the subjects were diagnosed as having some type of personality disorder (PD) in the SCID-II interview. Borderline PD was diagnosed in 56% of the subjects, making it the most frequent type of PD in this series. Frequent SB in these subjects involved: self-cutting, 40%; overdosing, 32%; self-strangulation, 14%; and jumping, 11%. Step-wise logistic regression analyses were conducted to examine the association of dichotomized SB-related clinical characteristics with diagnostic categories (affective disorders, psychotic disorders, substance use disorders, anxiety disorders, and cluster A, B and C PDs). The analysis demonstrated that three diagnostic categories were dominant in the association with clinical characteristics. Cluster B PD was associated with a history of overdosing, greater aggressiveness, interpersonal and life-situational life events, and childhood maltreatment (physical abuse and neglect). Anxiety disorders were related to histories of overdosing, dissociative symptoms in SB, excessive worry concerning life problems, and childhood neglect. Affective disorders were mainly associated with the characteristics of SB or SB-related symptoms: severe depressive symptoms and hopelessness, potentially fatal SB before admission such as self-strangulation, and dissociative symptoms in SB, though they did not show a significant relationship with pre-SB characteristics such as life events or childhood maltreatment. These findings will be helpful to develop treatment guidelines, SB-prevention strategies, and future research regarding suicidal psychiatric patients.

Template-directed formation of luminescent lanthanide complexes: versatile tools for colorimetric identification of single nucleotide polymorphism.

We present the facile technique of colorimetric SNP (single nucleotide polymorphism) analysis through DNA-templated cooperative complexation between a luminescent lanthanide ion (Ln(III): Tb(III) or Eu(III)) and two ODN (oligodeoxyribonucleotide) conjugates carrying a metal chelator. Families of complexane-type chelators and heterocyclic aromatic ligands were covalently attached to ODNs to form conjugates for application as capture and sensitizer probes. The sequences of the conjugates were designed so as to form a ternary tandem duplex with the target, where their auxiliary units face each other, providing a microenvironment to accommodate Ln(III). Only the combination of EDTA (ethylenediaminetetraacetic acid) conjugates and phen (1,10-phenanthroline) conjugates provided significant emissions with quantum yields of 3.3% and 1.5% for Tb(III) and Eu(III), respectively, in the presence of the target. Biallelic polymorphism in the TPMT (thiopurine S-methyltransferase) gene, wt/wt (G/G), mut/mut (C/C), and wt/mut (G/C), were distinguished as emissions in green, red, and yellow, respectively; the colors were identified even by the naked eye.

Colorimetric allele analysis based on the DNA-directed cooperative formation of luminous lanthanide complexes.

We present the facile technique of colorimetric SNP analysis through DNA-templated cooperative complexation between a luminescent lanthanide ion (Ln(3+): Tb(3+) or Eu(3+)) and two ODN (oligodeoxyribonucleotide) conjugates carrying a metal chelator. Ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthrorine (phen) were covalently attached to ODNs to form the conjugate probes, capture and sensitizer probes, respectively. The sequences of the conjugates were designed so as to form a tandem duplex with a target with their auxiliary units facing each other, providing a microenvironment to accommodate Ln(3+). The capture probes for the wild-type (wt) and the mutant (mut) of thiopurine S-methyltransferase gene, were mixed with equimolar amounts of Tb(3+) and Eu(3+), respectively. Then both of the allele specific capture probe solutions and the sensitizer probe were added to three different solutions containing the targets, wt/wt (G/G), mut/mut (C/C), and wt/mut (G/C). The solutions emitted in green, red, and yellow, respectively; the colors were identified even by the naked eye.