A cuvette for microelectrophoresis on agar and starch gel and for microimmunoelectrophoresis

Summary A simple cuvette is described which is to be used for serial analyses by means of modified micromethods of electrophoresis on agar and starch gel immune electrophoresis on agar. The instrument can be made in any laboratory.(Presented by Active Member of the Academy of Medical Sciences of the USSR G. A. Zedgenidze) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 61, No. 5, pp. 123–125, May, 1966     

AID and partners: for better and (not) for worse

Post-rearrangement diversification of the antibody repertoire relies on a DNA editing factor, the cytidine deaminase AID. How B lymphocytes avoid generalized mutagenesis while expressing high levels of AID remained a long-standing question. Genome-wide studies of AID targeting combined to the discovery of several co-factors controlling its recruitment and its local activity shed new light on this enigma.     

Macrophages require distinct arginine catabolism and transport systems for proliferation and for activation

In murine macrophages, as a result of arginine catabolism during activation, citruline is produced under the effect of IFN-gamma and LPS, and ornithine and polyamines by IL-4 and IL-10. For proliferation, arginine is required from the extracellular medium and is used for protein synthesis. During activation, most arginine (>95% in 6 h) was metabolized, while under proliferation only half was incorporated into proteins. Under basal conditions, this amino acid was preferentially transported by y(+)L activity. During activation, arginine transport increased drastically (4-5-fold) through y(+) cationic amino acid transporter (CAT) activity. By contrast, M-CSF induced only a modest increase in uptake (0.5-fold). The increase in arginine transport during activation, but not proliferation, was mediated by the SLC7A2/Cat2 gene. SLC7A1/Cat1 is constitutively expressed, and is not modified by proliferating or activating agents. M-CSF-dependent proliferation was not affected in the macrophages of SLC7A2 knockout mice; however, these cells showed a drastic reduction in the production of citruline or ornithine and polyamines during activation. The data show that a large increase in a specific transport system (CAT2) is necessary for activation-induced arginine metabolism, while arginine is in excess for the requirements of proliferation and a modest increase in transport occurs.     

DNA probes for Shiga-like toxins I and II and for toxin-converting bacteriophages.

A set of DNA probes has been developed to study the genes for Shiga-like toxins (SLT) and the bacteriophage from which these toxin genes were isolated. Under stringent conditions of hybridization (80 to 90% homology), these probes detect strains containing (i) SLT I-related genes, (ii) SLT II-related genes, (iii) phage sequences from the SLT I-converting phage H19A/933J, and (iv) phage sequences from the SLT II-converting phage 933W. Strain characterization by hybridization with the toxin gene probes was as accurate as methods that used toxin-specific antibody to determine toxin synthesis. Screening of different gram-negative bacteria with the toxin probes revealed that only two species carry sequences related to the SLT genes, Escherichia coli and Shigella dysenteriae 1. These results indicated that the lower levels of toxin activity observed in shigellae other than S. dysenteriae 1 are due to a gene(s) that is genetically distinct from that which encodes Shiga toxin. Analysis of enterotoxigenic, enteroinvasive, enteropathogenic, and enterohemorrhagic E. coli indicated that SLT genes are found primarily in the enterohemorrhagic E. coli strain group. Use of both the toxin and the phage probes has identified a variety of genotypic combinations of phage and toxin sequences which differ from those observed for the original toxin-converting phage isolates, for E. coli O157:H7 strain 933, and for E. coli O26:H11 strain H19.     

Expectancy for food or expectancy for chocolate reveals timing systems for metabolism and reward

The clock gene protein Per 1 (PER1) is expressed in several brain structures and oscillates associated with the suprachiasmatic nucleus (SCN). Restricted feeding schedules (RFS) induce anticipatory activity and impose daily oscillations of c-Fos and clock proteins in brain structures. Daily access to a palatable treat (chocolate) also elicits anticipatory activity and induces c-Fos expression mainly in corticolimbic structures. Here the influence of daily access to food or chocolate was explored by the analysis of the oscillatory patterns of PER1 in hypothalamic and corticolimbic structures. Wistar rats were exposed to RFS or to daily access to chocolate for 3 weeks. Persistence of food or chocolate entrained rhythms was determined 8 days after cessation of the feeding protocols. RFS and chocolate induced a phase shift in PER1 rhythmicity in corticolimbic structures with peak values at zeitgeber time 12 and a higher amplitude in the chocolate group. Both RFS and chocolate groups showed an upregulation of PER1 in the SCN. Food and chocolate entrained rhythms persisted for 8 days in behavior and in PER1 expression in the dorsomedial hypothalamic nucleus, accumbens, prefrontal cortex and central amygdala. The present data demonstrate the existence of different oscillatory systems in the brain that can be activated by entrainment to metabolic stimuli or to reward and suggest the participation of PER1 in both entraining pathways. Persistence and amplification of PER1 oscillations in structures associated with reward suggest that this oscillatory process is fundamental to food addictive behavior.     

Development and Initial Psychometrics for a Therapist Competence Instrument for CBT for Youth Anxiety

Therapist competence is an important component of treatment integrity. This article reports on the development and initial psychometric assessment of the Cognitive-Behavioral Treatment for Anxiety in Youth Competence Scale (CBAY-C), an observational instrument designed to capture therapist limited-domain competence (i.e., competence in the delivery of core interventions and delivery methods found in a specific psychosocial treatment program) in the delivery of the core practice elements in individual cognitive-behavioral treatment (ICBT) for youth anxiety. Treatment sessions (N = 744) from 68 youth participants (M age = 10.60 years, SD = 2.03; 82.3% Caucasian; 52.9% male) of the same ICBT program for youth anxiety from (a) an efficacy study and (b) an effectiveness study were independently scored by 4 coders using observational instruments designed to assess therapist competence, treatment adherence, treatment differentiation, alliance, and client involvement. Interrater reliability—intraclass correlation coefficients (2,2)—for the item scores averaged 0.69 (SD = 0.11). The CBAY-C item, scale, and subscale (Skills, Exposure) scores showed evidence of validity via associations with observational instruments of treatment adherence to ICBT for youth anxiety, theory-based domains (cognitive-behavioral treatment, psychodynamic, family, client centered), alliance, and client involvement. Important to note, although the CBAY-C scale, subscale, and item scores did overlap with a corresponding observational treatment adherence instrument independently rated by coders, the degree of overlap was moderate, indicating that the CBAY-C assesses a distinct component of treatment integrity. Applications of the instrument and future research directions discussed include the measurement of treatment integrity and testing integrity-outcome relations.     

American Society for Blood and Marrow Transplantation guidelines for training

Biol Blood Marrow Transplant 2001;7(10):577.