The role of recombination signal sequences in the preferential joining by deletion in DH-JH recombination and in the ordered rearrangement of the IgH locus

The bias favoring deletion over inversion in DH-JH rearrangement has been known for years, but the underlying mechanism has yet to be fully defined. It has been suggested that the ratio of deletion/inversion is determined by the combined effect of two factors: (i) the relative strengths of 5' and 3' recombination signal sequences (RSS) of a DH segment, and (ii) the efficiency with which the deletional product (one joint) forms relative to the inversional product (two joints). In this study, we analyzed for the first time the effect of factor 1 alone on the biased 3' RSS utilization in DH-JH joining by using deletional plasmids in an extrachromosomal substrate V(D)J recombination assay. It was found that the 3' RSS and associated coding end (12 bp) mediate recombination more efficiently than the 5' RSS/coding end DH-JH plasmids. These results demonstrate that the effect of the RSS/coding end alone can account, at least partially, for the predominant deletion in DH-JH recombination. The potential effect of the relative strength of RSS and associated coding end on the ordered rearrangement of DH-JH followed by VH to DH-JH was also assessed. When recombination frequencies of D-->J (3' DH to J3) were compared with frequencies of V-- >D (VHPJ14 to 3' DH or VHOX2 to 3' DH), it was found that V-->D joining was, if anything, more efficient than D-->J joining. Therefore, if all three segments were accessible, RSS/coding end effects would not contribute to the ordered rearrangement of the IgH locus.      

The RETAIN project: dicom teleradiology over an ATM-based network

The RETAIN project (Radiological Examinations Transfer on an ATM Integrated Network) has aimed at testing videoconferencing and DICOM image transfers to get advice about difficult radiological cases over an asynchronous transfer mode (ATM)-based network, which affords a more comfortable interface than narrow-band networks and allows exchange of complete image series using the DICOM format of studies. For this purpose, an experimental ATM network was applied between six university hospitals in four different countries. An assessment of the functionalities of the system was performed by means of log-file analysis, video recording of the sessions and forms filled out by the participants at the end of each session. Questionnaires were answered by the users at the end of the project to bring out perspectives of utilisation and added value. We discussed 43 cases during 20 sessions. For technical or organisational problems, only 20 of the 36 planned sessions took place. The throughput over ATM (10.5 Mbit/s, 20 times faster than six ISDN B-channels) was adequate. Despite the experimental configuration of the network, the system was considered as satisfactory by all the physicians. In 72 % of the sessions, the expected result (answer to the question) was gained. By common consent, videoconferencing was unanimously regarded as a prominent tool in improving the interaction quality. Asynchronous transfer mode is an efficient method for fast transferring of radiologic examinations in DICOM format and for discussing them through high-quality videoconferencing. Received: 26 October 1998; Revised: 25 February 1999; Accepted: 2 April 1999     

Reduction of atherosclerosis in cholesterol-fed rabbits and decrease of expressions of intracellular adhesion molecule-1 and vascular endothelial growth factor in foam cells by a water-soluble fraction of Polygonum multiflorum

Polygonum multiflorum stilbeneglycoside （PMS） is a water-soluble fraction of Polygonum multiflorum Thunb. , one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White （NZW） rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS （25, 50, or 100 mg/kg）. Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule （ICAM）-1 protein and the vascular endothelial growth factor （VEGF） protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells.     

Sulcal identification and neuronavigation in supratentorial cavernoma surgery

We present the use of cortical sulci, segmented from magnetic resonance imaging, in image guided neurosurgery. Sulcal information was transferred to a surgical microscope with enhanced reality features. This assistance was used for the resection of supratentorial cavernomas (7 patients). Sulci were semi-automatically segmented from 3D MRI data sets. Sulci close to the cavernoma were selected and transferred to the neuronavigation system which allows the superimposition of graphics into the right ocular of the microscope. Selected sulci were displayed on the workstation and superimposed into the ocular of the microscope. Cortical sulci proved to be useful for the recognition of the anatomical environment. The superimposed sulci helped to optimize location and size of the skin incision as well as to guide the access to the cavernoma by using the course of a sulcus as indirect trajectory.     

Deep venous thrombosis: epidemiology,acquired risk factors

Deep vein thrombosis is a frequent disease with an annual incidence reaching 5 per thousand among subjects over 75 years. Major acquired risk factors for venous thrombosis include surgery, neoplasm, reduced mobility or paresis, and a previous episode of deep vein thrombosis. Among women, hormonal status (pregnancy, oral contraceptive, hormone replacement therapy) is responsible for the majority of all venous thrombotic events. The impact of other factors is controversial: obesity, tobacco use and varicose veins. Venous thrombosis is a multifactorial disease and analysis of the interactions between acquired and inherited risk factors is an extremely interesting field of investigation.     

Association of hypertensive status and its drug treatment with lipid and haemostatic factors in middle-aged men: the PRIME study

Aims: To assess the association of hypertensive status and antihypertensive drug treatment with lipid and haemostatic levels in middle-aged men.Methods and results: Hypertensive status, antihypertensive drug treatment, total and high-density lipoprotein (HDL) cholesterol, triglyceride, apoproteins A-I and B, lipoparticles LpA-I, LpE:B and Lp(a), fibrinogen, plasminogen activator inhibitor-1 (PAI-1) activity and factor VII were assessed in a sample of men 50-59 years living in France (n = 7050) and Northern Ireland (n = 2374). After adjustment for age, body mass index, smoking status, educational level, country, alcohol drinking and hypolipidaemic drug treatment, untreated hypertensive subjects had higher levels of total cholesterol, triglyceride, apoproteins A-I and B and PAI-I activity than normotensive subjects. On univariate analysis, diuretics decreased total and HDL-cholesterol and apoproteins A-I and B; those differences remained after multivariate adjustment. Treatment with beta-blockers decreased total and HDL-cholesterol, apoprotein A-I and LpA-I, and this effect remained after multivariate adjustment. Calcium channel blockers decreased total cholesterol and apoproteins A-I and B; those differences remained significant after multivariate adjustment. ACE inhibitors decreased total cholesterol, triglycerides, apoprotein B and LpE:B; and this effect remained after multivariate adjustment. Analysis of the subjects on monotherapy showed beta-blockers to decrease total cholesterol and HDL parameters and angiotensin-converting enzyme (ACE) inhibitors to decrease low-density lipoprotein (LDL)-related parameters, while no effect was found for the other antihypertensive drugs.Conclusions: Hypertensive status is associated with an unfavourable lipid and haemostatic profile in middle-aged men. Antihypertensive treatment with beta-blockers decreases HDL parameters, whereas treatment with ACE inhibitors appears to decrease total cholesterol and LDL-related parameters.     

FISSURE SEALANT IN A NUTSHELL. EVIDENCE-BASED META-EVALUATION OF SEALANTS’ EFFECTIVENESS IN CARIES PREVENTION AND ARREST

ObjectiveThis meta-evaluation aimed to summarize all available evidence regarding different fissure sealants on occlusal caries prevention, arrest, retention rate, adverse effect, and cost-effectiveness; when compared with no intervention, other preventive or minimally-invasive procedures.Materials and MethodsThe systematic reviews and meta-analyses were identified via four electronic databases and manual searching. Two independent reviewers performed study selection, data extraction, quality assessment with AMSTAR-2.ResultsAmong the 366 records yielded, 38 systematic reviews were identified as eligible 24 of them included meta-analyses. Moderate evidence has supported the efficacies of resin-based sealants (RBS) in occlusal caries prevention, arrest and cost-effectiveness compared to no interventions. Low to very low certainty of evidence suggested similar effectiveness of glass-ionomer cements in caries prevention with RBS and more superior performance of resin infiltration in arresting non-cavitated occlusal lesions.ConclusionThis meta-evaluation supports the use of RBS on permanent molars to reduce occlusal caries occurrence, arrest lesion progression and alleviate oral health inequalities between individuals of different socioeconomic status. This meta-evaluation also advocates further research on glass-ionomer cements and resin infiltration with respect to their efficacies in caries prevention and arrest.