Requirement of CDC45 for Postimplantation Mouse Development

CDC45 is required for the initiation of DNA replication in Saccharomyces cerevisiae and functions as a DNA polymerase alpha loading factor in Xenopus, but its role in mammalian DNA replication is unknown. To investigate the genetic and physiological functions of CDC45, we used a gene targeting strategy to generate mice lacking a functional CDC45 gene. Homozygous mutant mice lacking a functional CDC45 gene underwent uterine implantation and induced uterine decidualization but did not develop substantially thereafter. Detailed analysis of CDC45 null embryos cultured in vitro revealed impaired proliferation of the inner cell mass. These findings make CDC45 the only putative replication factor experimentally proven to be essential for mammalian development. The CDC45 gene localizes to human chromosome 22q11.2 in the DiGeorge syndrome critical region (DGCR). Almost 90% of individuals with congenital cardiac and craniofacial defects have a monoallelic deletion in the DGCR that includes CDC45. We report here that heterozygous mutant mice develop into adulthood without any apparent abnormalities, so that it is unlikely that hemizygosity of CDC45 alone is responsible for the cardiac and craniofacial defects in the congenital syndromes.     

Homoeologous loci control the accumulation of seed glucosinolates in oilseed rape (Brassica napus).

The genetic control of seed glucosinolate content in oilseed rape was investigated using two intervarietal backcross populations. Four QTLs segregating in the population derived from a Brassica napus L. 'Victor' x Brassica napus L. 'Tapidor' cross, together accounting for 76% of the phenotypic variation, were mapped. Three of these loci also appeared to control the accumulation of seed glucosinolates in a Brassica napus L. 'Bienvenu' x 'Tapidor' cross, and accounted for 86% of the phenotypic variation. The three QTLs common to both populations mapped to homoeologous regions of the B. napus genome, suggesting that seed glucosinolate accumulation is controlled by duplicate genes. It was possible to extend the comparative analysis of QTLs controlling seed glucosinolate accumulation by aligning the published genetic maps generated by several research groups. This comparative mapping demonstrated that high-glucosinolate varieties often carry low-glucosinolate alleles at one or more of the loci controlling seed glucosinolate accumulation.     

The Food Amount Rating Scale: Development,Reliability, and Validity

Objective: Implied in measures of binge eating is the assumption that individuals agree on what comprises a large amount of food. However, whether individuals estimate food amounts similarly or whether estimation of food amounts varies as a function of personal characteristics is unknown. The Food Amount Rating Scale (FARS) is a standardized set of stimuli for assessing individuals’ judgment of food amounts. Research Methods and Procedures: Two versions of the FARS were developed, and their psychometric properties were assessed. These versions are the same in all respects except that the rater is instructed to rate various food amounts for the average woman on Form W and for the average man on Form M. Results: Content validity was confirmed by 14 researchers and research assistants in the field of eating disorders. The FARS is a 24-item inventory with adequate test–retest reliability (Form W = 0.85; Form M = 0.87) and split–half reliability (Form W = 0.90; Form M = 0.89). Convergent validity is suggested by the finding that ratings for the average woman (Form W) were significantly higher than ratings for the average man (Form M). Discussion: The FARS is a psychometrically sound tool for use in basic research focused on identifying whether the subjective judgment of food amounts varies as a function of personal characteristics and in clinical research where it may be important to know how individuals judge food amounts.     

Cutting edge: inducible costimulator protein regulates both Th1 and Th2 responses to cutaneous leishmaniasis.

The CD28 family member inducible costimulator protein (ICOS) has an important role in T cell differentiation and Ig class switching. To investigate the role of ICOS in vivo, ICOS-/- mice were infected s.c. with Leishmania mexicana. While wild-type mice developed large, cutaneous lesions, the growth of lesions and tissue histopathology was significantly delayed in ICOS-/- mice. ICOS-/- mice exhibited marked decreases in both Th1 and Th2 cytokine production and profound defects in L. mexicana-specific Ig isotype class switching to IgG1 and IgG2a and reduced total IgE levels. Our findings indicate that ICOS is a key regulator of both Th1 and Th2 responses and has a role in controlling cutaneous L. mexicana infection.     

Mechanical methods of reducing blood transfusion in cardiac surgery: randomised controlled trial

ObjectiveTo assess the effectiveness of two mechanical methods of blood conservation in reducing the need for allogeneic red blood cells or coagulation products during cardiac surgery.DesignRandomised controlled trial.SettingRegional cardiac centre in a teaching hospital in Southampton.Participants263 adults aged 18-80 years undergoing elective coronary artery bypass surgery entered the study, of whom 252 completed the trial. All patients received routine perioperative care. Patients were allocated to one of three treatment groups: intraoperative cell salvage, intraoperative cell salvage with acute perioperative normovolaemic haemodilution, or no mechanical blood conservation. There were 84 patients in each group.ResultsOf the patients in the intraoperative cell salvage group, 26 were given a transfusion of allogeneic blood, compared with 43 in the control group (odds ratio 0.43 (95% confidence interval 0.23 to 0.80)). The mean number of units of allogeneic blood transfused per patient in the intraoperative cell salvage group was 0.68 units (SD=1.55), compared with 1.07 (1.56) units in the control group. 32 of the patients in the intraoperative cell salvage group were given any blood product, compared with 47 in the control group (odds ratio 0.47 (0.25 to 0.89); P=0.019). Combining acute perioperative normovolaemic haemodilution with intraoperative cell salvage conferred no additional benefits.ConclusionsAn intraoperative cell salvage device should be used in elective coronary artery bypass grafting. Pharmacological strategies may achieve further reductions in blood transfusions. Yet further reductions in blood transfusions could be achieved if the lower safe limit of haemoglobin concentration in patients undergoing cardiac surgery were known.

What is already known on this topic

Patients undergoing elective coronary artery bypass surgery often need a blood transfusionRecent meta-analyses have shown that the mechanical blood conservation techniques of intraoperative cell salvage and acute perioperative normovolaemic haemodilution may reduce the need for transfusion, but flawed methods in trials mean that clear evidence in cardiac surgery is lacking

What this study adds

Intraoperative cell salvage significantly reduces the number of patients needing an allogeneic blood transfusionCombining acute perioperative normovolaemic haemodilution with intraoperative cell salvage does not confer any additional benefit     

Potent P1' biphenylmethyl substituted aggrecanase inhibitors.

A series of cis-1(S)2(R)-amino-2-indanol based compounds with a biphenylmethyl group at the P1' position was found to be potent aggrecanase inhibitors. Both compounds 2j and 2n possessed very high aggrecanase affinity (IC(50)=1.5nM), and showed excellent selectivity over MMP-1 and MMP-9, with moderate selectivity against MMP-2.     

Development of transgenic tobacco harboring a zeatin O-glucosyltransferase gene from Phaseolus

Summary Zeatin and its derivatives are major consituents of higher plant cytokinins. Metabolic steps modifying the isoprenoid side chain, such as O-glycosylation, are expected to have a direct bearing on cytokinin-mediated processes. To examine this possibility, transgenic tobacco plants were generated harboring a gene (ZOG1) encoding a zeatin O-glucosyltransferase from Phaseolus lunatus under the control of a constitutive (35S) and an inducible (Tet) promoter. The presence of the transgene resulted in elevated enzyme production and conversion of exogenous zeatin to its O-glucoside, confirming the expression of the ZOG1 gene in transgenic plants. Endogenous O-glucosylzeatin was increased from less than 1 pmol per g fresh weight in leaves and roots of controls to 26 and 68 pmol per g fresh weight in leaves and roots of 35S-ZOG1 transformants, respectively. In cytokinin/auxin interaction experiments, Tet-ZOG1 leaf discs, in the presence of tetracycline, required 10-fold higher zeatin concentrations for the formation of shoots and callus than the controls. In 35S-ZOG1 plants, developmental changes included adventitious root formation on the lower stems, shorter stature, and axillary shoot growth. Thus, increased zeatin O-glucosylation in detached, cytokinin-dependent tissues leads to a shift in the response to exogenous zeatin indicative of cytokinin sequestering. In whole plants the effect can simulate a reduction or a rise in cytokinin activity depending on the tissue and stage of development. The use of tissue- and stagespecific promoters in the future will allow more precise analyses and targeted growth alterations.