2-Hour cytomegalovirus pp65 antigenemia assay for rapid quantitation of cytomegalovirus in blood samples

Of 109 blood samples tested for cytomegalovirus (CMV) antigenemia, 18 (16.5%) were positive. CMV Brite detected 13 and CMV Brite Turbo detected 16 of the 18 positives. There was no significant difference in the number of positive cells detected per sample. The seven discrepant samples contained a median of only one positive cell.     

Staphylococcal exopolysaccharides inhibit lymphocyte proliferative responses by activation of monocyte prostaglandin production.

The glycocalyx (exopolysaccharides) of Staphylococcus epidermidis has been reported to inhibit a variety of host defense mechanisms. We have examined the inhibitory effects of glycocalyx on the proliferation of human peripheral blood mononuclear cells (PBMC) and the mechanism of this inhibition. Glycocalyx isolated and partially purified under endotoxin-free conditions from defined liquid medium cultures of S. epidermidis and Staphylococcus lugdunensis inhibited the proliferative response of PBMC when added to cultures at 10 to 100 micrograms/ml. Glycocalyx-mediated inhibition of phytohemagglutinin-stimulated proliferation of PBMC required the presence of plastic-adherent peripheral blood monocytes. Culture supernatants of monocytes stimulated with glycocalyx contained a soluble factor that inhibited the proliferation of monocyte-depleted PBMC. This soluble inhibitory factor was not produced in the absence of glycocalyx or in the presence of both glycocalyx and indomethacin. Analysis of the supernatants of cultures of adherent monocytes revealed that glycocalyx from S. epidermidis and from S. lugdunensis could activate monocyte production of prostaglandin E2 (PGE2), human interleukin-1, and tumor necrosis factor alpha. The addition of purified PGE2, at the same levels of PGE2 (greater than or equal to 10(-9) M) generated in the monocyte cultures, to PBMC cultures resulted in a similar inhibition of proliferative responses. It is concluded that, contrary to previous suggestions, the bacterial glycocalyx does not have a direct inhibitory effect on T lymphocytes. However, it does appear that glycocalyx from coagulase-negative staphylococci can activate monocyte PGE2 production and that it is this activity that in turn contributes to the inhibition of T-cell proliferation.     

Effect of delayed specimen processing on cytomegalovirus antigenemia test results.

Blood samples held at either 4 degrees C or room temperature for 1 day had similar mean decreases in number of cytomegalovirus antigenemia-positive cells (52 to 55%) and similar false-negative test results (13 to 14%). After 2 days, samples held at 4 degrees C showed no further decline, whereas samples held at room temperature had a mean 81% decrease in positive cells, a 32% false-negative rate, and a more marked deterioration in cell morphology.     

Randomized controlled trial of brief cognitive behaviour therapy versus treatment as usual in recurrent deliberate self-harm: the POPMACT study

BACKGROUND: We carried out a large randomized trial of a brief form of cognitive therapy, manual-assisted cognitive behaviour therapy (MACT) versus treatment as usual (TAU) for deliberate self-harm. METHOD: Patients presenting with recurrent deliberate self-harm in five centres were randomized to either MACT or (TAU) and followed up over 1 year. MACT patients received a booklet based on cognitive behaviour therapy (CBT) principles and were offered up to five plus two booster sessions of CBT from a therapist in the first 3 months of the study. Ratings of parasuicide risk, anxiety, depression, social functioning and global function, positive and negative thinking, and quality of life were measured at baseline and after 6 and 12 months. RESULTS: Four hundred and eighty patients were randomized. Sixty per cent of the MACT group had both the booklet and CBT sessions. There were seven suicides, five in the TAU group. The main outcome measure, the proportion of those repeating deliberate self-harm in the 12 months of the study, showed no significant difference between those treated with MACT (39%) and treatment as usual (46%) (OR 0.78, 95% CI 0.53 to 1.14, P=0.20). CONCLUSION: Brief cognitive behaviour therapy is of limited efficacy in reducing self-harm repetition, but the findings taken in conjunctin with the economic evaluation (Byford et al. 2003) indicate superiority of MACT over TAU in terms of cost and effectiveness combined.     

The GAP-related domain of tuberin, the product of the TSC2 gene, is a target for missense mutations in tuberous sclerosis

Tuberous sclerosis is an autosomal dominant trait in which the dysregulation of cellular proliferation and differentiation results in the development of hamartomatous growths in many organs. The TSC2 gene is one of two genes determining tuberous sclerosis. Inactivating germline mutations of TSC2 in patients with tuberous sclerosis and somatic loss of heterozygosity at the TSC2 locus in the associated hamartomas indicate that TSC2 functions as a tumour suppressor gene and that loss of function is critical to expression of the tuberous sclerosis phenotype. The TSC2 product, tuberin, has a region of homology with the GTPase activating protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in vitro. Here we show that the region of homology between tuberin and human rap1GAP and the murine GAP mSpa1 is more extensive than previously reported and spans approximately 160 amino acid residues encoded within exons 34-38 of the TSC2 gene. Single strand conformation polymorphism analysis of these exons in 173 unrelated patients with tuberous sclerosis and direct sequencing of variant conformers together with study of additional family members enabled characterisation of disease associated mutations in 14 cases. Missense mutations, which occurred in exons 36, 37 and 38 were identified in eight cases, four of whom shared the same recurrent change P1675L. Each of the five different missense mutations identified was shown to occur de novo in at least one sporadic case of tuberous sclerosis. The high proportion of missense mutations detected in the region of the TSC2 gene encoding the GAP-related domain supports its key role in the regulation of cellular growth.      

Production and characterization of murine models of classic and intermediate maple syrup urine disease

Background  

Maple Syrup Urine Disease (MSUD) is an inborn error of metabolism caused by a deficiency of branched-chain keto acid dehydrogenase. MSUD has several clinical phenotypes depending on the degree of enzyme deficiency. Current treatments are not satisfactory and require new approaches to combat this disease. A major hurdle in developing new treatments has been the lack of a suitable animal model.     

Regulation of DAF-2 receptor signaling by human insulin and ins-1, a member of the unusually large and diverse C. elegans insulin gene family

The activity of the DAF-2 insulin-like receptor is required for Caenorhabditis elegans reproductive growth and normal adult life span. Informatic analysis identified 37 C. elegans genes predicted to encode insulin-like peptides. Many of these genes are divergent insulin superfamily members, and many are clustered, indicating recent diversification of the family. The ins genes are primarily expressed in neurons, including sensory neurons, a subset of which are required for reproductive development. Structural predictions and likely C-peptide cleavage sites typical of mammalian insulins suggest that ins-1 is most closely related to insulin. Overexpression of ins-1, or expression of human insulin under the control of ins-1 regulatory sequences, causes partially penetrant arrest at the dauer stage and enhances dauer arrest in weak daf-2 mutants, suggesting that INS-1 and human insulin antagonize DAF-2 insulin-like signaling. A deletion of the ins-1 coding region does not enhance or suppress dauer arrest, indicating a functional redundancy among the 37 ins genes. Of five other ins genes tested, the only other one bearing a predicted C peptide also antagonizes daf-2 signaling, whereas four ins genes without a C peptide do not, indicating functional diversity within the ins family.     

Cloning, expression and functional characterisation of a peroxiredoxin from the potato cyst nematode Globodera rostochiensis

We report the cloning, expression and functional characterisation of a peroxidase belonging to the peroxiredoxin family from the potato cyst nematode Globodera rostochiensis, the first molecule of this type from any nematode parasitic on plants. The G. rostochiensis peroxiredoxin catalyses the breakdown of hydrogen peroxide, but not cumene or t-butyl hydroperoxide, in a trypanosomatid reducing system comprising trypanothione reductase, trypanothione and tryparedoxin. In common with its homologues from Onchocerca volvulus and Brugia malayi, the G. rostochiensis enzyme is present on the surface of invasive and post-infective juveniles despite the apparent lack of a cleavable N-terminal signal peptide. The possibility that the G. rostochiensis peroxiredoxin plays a role in protection of the parasite from plant defence responses is discussed.