Influência da Adição de Hidroxietil Acrilamida em um Cimento Resinoso Experimental Fotopolimerizável

O objetivo foi avaliar as propriedades de um cimento resinoso experimental contendo hidroxietil acrilamida. Foram formulados quatro grupos de cimentos resinosos fotopolimerizáveis: GHEMA0 e GHEMA1 (70 wt% BisGMA/30 wt% HEMA) e GHEAA0 e GHEAA1 (70 wt% BisGMA/30 wt% HEAA). Como sistema iniciador/ativador foi adicionado aos grupos GHEMA0 e GHEAA0 1% mol de CQ e nos grupos GHEMA1 e GHEAA1 (1% mol de CQ e 1% mol de EDAB). A todos os grupos foi acrescentada uma carga de 40% em peso de fluoreto de itérbio. Os cimentos foram avaliados quanto a radiopacidade (n6), colorimetria 24h após imersão em água e óleo mineral (n5), resistência coesiva (n12) e microcisalhamento (n12). Os dados foram analisados por ANOVA de uma via e Tukey com um nível de significância de 5%. Na radiopacidade o GHEAA1 e GHEAAO não apresentaram diferença a 1mm de alumínio. Na colorimetria, o GHEAA1 imerso em água obteve o maior valor de “L” (p<0,05) que não teve diferença com os demais grupos (p>0,05), com exceção do GHEMA1 em óleo. Para os valores de “a” o GHEMA1 em óleo foi estatisticamente maior (p<0,001). Em relação ao “b”, o GHEAA0 em óleo e água obtiveram os maiores valores (p<0,05). A resistência coesiva foi maior para os grupos metacrilato quando comparado aos com acrilamida, sendo que GHEAA1 foi maior que GHEAAO (p<0,05). O microcisalhamento foi significativamente maior para o grupo metacrilato (p<0,05), sem diferença nos grupos acrilamida. Com base nesses resultados, pode-se concluir que o cimento fotopolimerizável com o monômero metacrilato obteve valores superiores em relação aos com acrilamida.Palavras-chave: Acrilamidas. Cimentos de Resina. Metacrilatos.

Influência da Concentração de Ácido Fluorídrico em Três Cerâmicas para CAD/CAM

O objetivo foi avaliar a influência de duas concentrações de ácido fluorídrico em cerâmicas para CAD/CAM. Amostras (n6) de IPS Empress CAD, IPS e.max CAD e Vita Suprinity, medindo 7 mm x 4 mm x 1,2 mm foram divididas nos grupos controle, condicionada com ácido fluorídrico 5% e 10%. Superfície foi analisada por MEV, rugosidade e ângulo de contato. Para microcisalhamento, usou- se adesivo universal (Scotchbond Universal) e cimento resinoso dual (Relyx Ultimate). Análise estatística realizada por ANOVA de duas vias. Para o ângulo de contato do e.max, obteve-se médias de 71,12 (5%) e 72,11 (10%). Suprinity, 50,38 (5%), 33,05  (10%). Ambas sem diferença estatística entre 5% e 10%. Empress 69,97 (5%) e 84,38 (10%), e somente condicionamento a 10% com p<0,05. Na análise da rugosidade, e.max apresentou valores de 0,321 (5%) e 0,314 (10%) Suprinity 0,375 (5%) e 0,377 (10%) Empress 0,423 (5%) e 1,03 (10%), com diferença apenas entre condicionamento com 5 % e 10% para Empress. Comparando-se as cerâmicas, Empress condicionada com 10% apresentou-se diferente das demais. Microcisalhamento teve como médias para e.max 7,66 (5%)  e 5,05 (10%) Suprinity 7,03 (5%) e 11,92 (10%) Empress 4,52 (5%) e 4,04 (10%), sem diferença estatística entre as concentrações de ácido fluorídrico. Análise de fratura mostrou falhas predominantemente adesivas. Com base nestes resultados, pode-se concluir que condicionamento cerâmico com ácido fluorídrico com concentração de 10% interfere no molhamento e rugosidade da cerâmica Empress.Palavras-chave: Cerâmica. CAD-CAM. Ácido Fluorídrico.

The systemic control of circadian gene expression

The mammalian circadian timing system consists of a central pacemaker in the brain's suprachiasmatic nucleus (SCN) and subsidiary oscillators in nearly all body cells. The SCN clock, which is adjusted to geophysical time by the photoperiod, synchronizes peripheral clocks through a wide variety of systemic cues. The latter include signals depending on feeding cycles, glucocorticoid hormones, rhythmic blood-borne signals eliciting daily changes in actin dynamics and serum response factor (SRF) activity, and sensors of body temperature rhythms, such as heat shock transcription factors and the cold-inducible RNA-binding protein CIRP. To study these systemic signalling pathways, we designed and engineered a novel, highly photosensitive apparatus, dubbed RT-Biolumicorder. This device enables us to record circadian luciferase reporter gene expression in the liver and other organs of freely moving mice over months in real time. Owing to the multitude of systemic signalling pathway involved in the phase resetting of peripheral clocks the disruption of any particular one has only minor effects on the steady state phase of circadian gene expression in organs such as the liver. Nonetheless, the implication of specific pathways in the synchronization of clock gene expression can readily be assessed by monitoring the phase-shifting kinetics using the RT-Biolumicorder.

The plant strengthening root endophyte Piriformospora indica: potential application and the biology behind

The successful conversion of plant production systems from conventional resource-exhausting to sustainable strategies depends on knowledge-based management of environmental factors. Root-inhabiting fungi came more and more into focus because their hyphae connect in ideal manner resources and challenges of the surrounding with the plant. A paradigm for such root endophytes is presented by the basidiomycete Piriformospora indica. This fungus possesses a broad host spectrum and positively affects different aspects of plant performance. This so far unique combination of attributes makes P. indica and its close relatives among the Sebacinales very interesting tools for cultivation of various crops. This review will outline the different aspects required to apply this root endophyte in agri- and horticulture concerning plant growth, plant nutrition and plant defence or tolerance thereby explaining what is known about the biological basis for the observed effects. Open questions and challenges for successful inoculum production and application will be discussed.

Radiovirotherapy: principles and prospects in oncology

Radiovirotherapy is defined as the use of viruses to deliver radioisotopic treatment into infected cells. Oncolytic viruses are able to selectively target and kill cancer cells. The combination of oncolytic viruses and radiation therapies can have synergistic antitumour properties. Viruses may act as radiosensitizers, and radiations can increase viral oncolytic properties. The combination of oncolytic viruses with a virally-directed radioisotope therapy is an innovative method to combine viruses and radiation therapy, selectively within the tumour cells. The sodium/iodide symporter (NIS) is the main transgene that has been studied for this approach. NIS can mediate the uptake of isotopes of iodine and technetium 99m for in vivo gene expression imaging and therapy. This review highlights the principles of radiovirotherapy, and its recent progress. Better understanding of the regulation of NIS opens up pathways by which to potentiate the functional expression of NIS. In terms of the therapeutic isotope, Iodine-131 has been most frequently studied but other isotopes (astatine- 211, rhenium-188) are of growing interest. Oncolytic viruses are able to infect selectively and replicate in cancer cells and promising early phase clinical trials have been recently published. Their development allows a better selectivity of viral infection and adds a virus-specific cytotoxicity to the therapeutic approach. Active research into strategies such as immunosuppressive treatment and cell-based carrier systems is seeking to circumvent the host antiviral immune response and, thus, increase the potential for systemic delivery. Finally, other anticancer therapies such as chemotherapy and external beam radiotherapy may have a synergistic effect with radiovirotherapy and such combinatorial approaches offering the prospect of accelerated translation into clinical studies.

Allergenic activity of different tomato cultivars in tomato allergic subjects

BACKGROUND

Tomatoes (Solanum lycopersicum) are consumed worldwide and their amount of consumption is associated with the prevalence of tomato allergy. Therefore, identification of tomato cultivars with reduced allergenicity would potentially increase the quality of life of affected subjects.

OBJECTIVE

In this study, we examined the allergenic and biological activity of two different tomato cultivars in tomato allergic subjects.

METHODS

Twenty-five subjects with tomato allergy were identified using double-blind, placebo-controlled food challenges (DBPCFC). We applied skin prick test (SPT) and further DBPCFC to investigate the clinical differences between two tomato cultivars ('Reisetomate' and 'Matina'). To examine the molecular basis of allergenic activity, immunoblotting and basophil activation test (BAT) were performed.

RESULTS

The cultivar 'Reisetomate' induced significantly less positive skin reactions (P = 0.045) and elicited fewer symptoms after oral challenge compared with 'Matina' (P = 0.047). Molecular assessment revealed that IgE-binding profiles were variable on an interindividual basis, but no major differences between 'Reisetomate' and 'Matina' were detectable. In contrast, BAT underpinned the clinical differences evoked by the different tomato cultivars and showed a left-shift of the dose-response curve obtained for 'Matina' extract (P = 0.046).

CONCLUSIONS AND CLINICAL RELEVANCE

Tomato cultivars promote a distinct clinical reactivity in tomato allergic subjects, demonstrated using SPT, DBPCFC and BAT. The molecular background for these differences could not be clarified, as the IgE-binding profiles did not reveal significant alterations. This might be due to instabilities of physicochemical sensitive proteins and/or different isoform expression of allergens.

[Q fever: an overview]

Q fever, a zoonosis caused by the gram-negative bacterium Coxiella burnetii, occurs worldwide and affects both humans and animals. Ruminants are considered to be the main source of infection of humans, with the main route of infection being through inhalation of the organism of fine-particle aerosols. Abortion is the main clinical sign in ruminants. During and after abortion, large quantities of the bacterium are shed via the placenta and other vaginal secretions. The bacterium may also be present in faeces and milk. The bacterium can survive for a long time in the environment after shedding and can be spread over long distances. Seroprevalence among cattle is rather high in the Netherlands and in many other countries. Infection is diagnosed by detecting antibodies against the bacterium or the bacterium itself by means of a PCR method. The efficacy of using antibiotics or vaccines for treatment or prevention of the disease in cattle is still unclear and there are currently no effective disease control programmes.

Development of a specific PCR assay for the detection of Rhizoctonia solani AG 1-IB using SCAR primers

AIMS

The aim of this study was to develop a specific and sensitive identification method for Rhizoctonia solani AG 1-IB isolates based on phylogenetic relationships of R. solani AG-1 subgroups using rDNA-internal transcribed spacer (rDNA-ITS) sequence analysis.

METHODS AND RESULTS

A neighbour-joining tree analysis of 40 rDNA-ITS sequences demonstrated that R. solani AG-1 isolates cluster separately in six subgroups IA, IB, IC, ID, IE and IF. A molecular marker was generated from a random amplified polymorphic DNA fragment (RAPD). After conversion into a sequence-characterized amplified region (SCAR), a specific primer set for identification of subgroup AG 1-IB was designed for use in a polymerase chain reaction (PCR). The primer pair amplified a single DNA product of 324 bp.

CONCLUSIONS

R. solani AG-1 subgroups were discriminated by sequence analysis of the ITS region. The designed SCAR primer pair allowed an unequivocal and rapid detection of R. solani AG 1-IB in plant and soil samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

Sequence analysis of the rDNA-ITS region can be used for differentiation of subgroups within AG-1. The use of the developed SCAR primer set allowed a reliable and fast identification of R. solani AG 1-IB and provides a powerful tool for disease diagnosis.

Evaluation of the induction of NS3 specific BVDV antibodies using a commercial inactivated BVDV vaccine in immunization and challenge trials

In order to evaluate whether cattle vaccinated with an inactivated vaccine against bovine viral diarrhoea virus (BVDV) can be differentiated serologically from BVDV infected animals, two different aspects were investigated. Firstly the antibody response against non-structural proteins (NS) was measured after multiple vaccinations of cattle with a single or double dose of a commercially available inactivated BVDV vaccine. In a second study, the animals were first vaccinated with the product, and then infected with BVDV. The antibody response was determined in four different commercial ELISA systems. It can be concluded, that the inactivated BVD vaccine exhibits properties of a marker vaccine when an appropriate antibody NS3 ELISA is applied: after vaccination NS3-specific antibody levels are low or undetectable, but the vaccination does in the present study not show any interference with the development of antibodies against NS3 after subsequent field virus infection.

Molecular analysis of sleep

Rest or sleep in all animal species constitutes a period of quiescence necessary for recovery from activity. Whether rest and activity observed in all organisms share a similar fundamental molecular basis with sleep and wakefulness in mammals has not yet been established. In addition and in contrast to the circadian system, strong evidence that sleep is regulated at the transcriptional level is lacking. Nevertheless, several studies indicate that single genesmay regulate some specific aspects of sleep. Efforts to better understand or confirm the role of known neurotransmission pathways in sleep-wake regulation using transgenic approaches resulted so far in only limited new insights. Recent gene expression profiling efforts in rats, mice, and fruit flies are promising and suggest that only a few gene categories are differentially regulated by behavioral state. How molecular analysis can help us to understand sleep is the focus of this chapter.

Identification of heavy metal-induced genes encoding glutathione S-transferases in the arbuscular mycorrhizal fungus Glomus intraradices

Arbuscular mycorrhizal fungi are able to alleviate the stress for plants caused by heavy metal contamination of soil. To analyze the molecular response of arbuscular mycorrhizal fungi to these pollutants, a subtractive cDNA library was constructed using RNA from Glomus intraradices extraradical hyphae of a root organ culture treated with a mixture of Cd, Zn, and Cu. Screening by reverse Northern blot analysis indicated that, among 308 clones, 17% correspond to genes up-regulated by heavy metals. Sequence analysis of part of the clones resulted, amongst others, in the identification of six genes putatively coding for glutathione S-transferases belonging to two different classes of these enzymes. Expression analyses indicated that the genes are differentially expressed during fungal development and that their RNA accumulation dramatically increases in extraradical hyphae grown in a heavy metal-containing solution.

EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology

The European procedural guidelines for radionuclide imaging of myocardial perfusion and viability are presented in 13 sections covering patient information, radiopharmaceuticals, injected activities and dosimetry, stress tests, imaging protocols and acquisition, quality control and reconstruction methods, gated studies and attenuation-scatter compensation, data analysis, reports and image display, and positron emission tomography. If the specific recommendations given could not be based on evidence from original, scientific studies, we tried to express this state-of-art. The guidelines are designed to assist in the practice of performing, interpreting and reporting myocardial perfusion SPET. The guidelines do not discuss clinical indications, benefits or drawbacks of radionuclide myocardial imaging compared to non-nuclear techniques, nor do they cover cost benefit or cost effectiveness.

Expression profiling of up-regulated plant and fungal genes in early and late stages of Medicago truncatula-Glomus mosseae interactions

Suppression subtractive hybridization (SSH), expression profiling and EST sequencing identified 12 plant genes and six fungal genes that are expressed in the arbuscular mycorrhizal symbiosis between Medicago truncatula and Glomus mosseae. All the plant genes and three of the fungal genes were up-regulated in symbiotic tissues. Expression of 15 of the genes is described for the first time in mycorrhizal roots and two are novel sequences. Six M. truncatula genes were also activated during appressorium formation at the root surface, suggesting a role in this early stage of mycorrhiza establishment, whilst the other six plant genes were only induced in the late stages of mycorrhization and could be involved in the development or functioning of the symbiosis. Phosphate fertilization had no significant influence on expression of any of the plant genes. Expression profiling of G. mosseae genes indicated that two of them may be associated with appressorium development on roots and one with arbuscule formation or function. The other three fungal genes were expressed throughout the life-cycle of G. mosseae.

Differential RNA accumulation of two beta-tubulin genes in arbuscular mycorrhizal fungi

RNA was isolated from spores of different arbuscular mycorrhizal (AM) fungi and used for RT-PCR with degenerate primers for beta-tubulin genes. PCR products were cloned and the sequence of several clones was analysed for each fragment. Comparison of sequences identified two loci for beta-tubulin genes with different GC content and codon usage. Btub1 sequences were most similar to beta-tubulin genes from the Oomycota, while Btub2 sequences showed highest similarity to sequences from the Zygomycota. RT-PCR experiments were carried out to monitor RNA accumulation patterns of Btub1 and Btub2 in asymbiotic germinating spores and in symbiotic extraradical hyphae of three different AM fungi. This indicated that Btub1 is constitutively expressed in Gigaspora rosea, but down-regulated during symbiosis in Glomus mosseae and Glomus intraradices. In contrast, Btub2 showed constitutive expression in the two Glomus species, but down-regulation in G. rosea. Further analysis of different fungi indicated that Btub2 primers could be used to specifically monitor RNA accumulation of AM fungi in environmental samples.

[Methodological aspects related to the determination of the relative renal function using 99mTC MAG3]

The aim of the study was to evaluate three different methods for calculating the split renal function in patients with only one functioning kidney, keeping in mind that the split function should be zero on the side of the non-functioning kidney.

PATIENTS

We retrospectively selected 28 99mTc MAG3 renograms performed in children, 12 with unilateral nephrectomy, 4 with unilateral agenesis and 12 with a non-functioning kidney.

METHODS

A renal and perirenal region of interest (ROI) were delineated around the functioning kidney. The ROIs around the empty kidney were drawn symmetrically to the contralateral side. The split renal function was calculated using three different methods, the integral method, the slope method and the Patlak-Rutland algorithm.

RESULTS

For the whole group of 28 kidneys as well as for the three categories of patients, the three methods provided a split function on the side of the non-functioning kidney close to the zero value, regardless of whether the empty kidney was the left or the right one.

CONCLUSION

We recommend the use of the integral method for the whole range of split renal function with 99mTc MAG3. No significant improvement was obtained by means of the more sophisticated Patlak-Rutland method.

Magnesium involvement in sleep: genetic and nutritional models

Alterations of peripheral magnesium (Mg) concentration have been reported in association with several behavioral disorders and sleep organization. Blood Mg regulation is under a strong genetic control, whereas brain Mg regulation does not seem to be affected. We have studied peripheral and central levels of Mg and analyzed sleep in two lines of mice selected for low (MGL) and high (MGH) red blood cell (RBC) Mg levels. The same variables were also studied in C57BL/6J mice before and after 3 weeks of Mg deficiency. Whereas blood Mg was highly affected by the selection, brain Mg exhibited only small differences between the two lines. In contrast, Mg deficiency strongly decreased both central and peripheral Mg levels. Sleep analysis indicated that in both models the amount of paradoxical sleep was lower in mice with higher Mg levels. The amplitude of daily variation in sleep and slow-wave sleep delta power was markedly decreased in MGH line. Quantitative electroencephalogram (EEG) analysis also revealed a faster theta peak frequency in MGH mice, irrespective of behavioral states. Central Mg showed significant correlations with the amount of paradoxical sleep and sleep consolidation. However, because the direction of these correlations was not consistent, it is concluded that optimal, (physiological) rather than high or low, Mg levels are needed for normal sleep regulation.

The homeostatic regulation of sleep need is under genetic control

Delta power, a measure of EEG activity in the 1-4 Hz range, in slow-wave sleep (SWS) is in a quantitative and predictive relationship with prior wakefulness. Thus, sleep loss evokes a proportional increase in delta power, and excess sleep a decrease. Therefore, delta power is thought to reflect SWS need and its underlying homeostatically regulated recovery process. The neurophysiological substrate of this process is unknown and forward genetics might help elucidate the nature of what is depleted during wakefulness and recovered during SWS. We applied a mathematical method that quantifies the relationship between the sleep-wake distribution and delta power to sleep data of six inbred mouse strains. The results demonstrated that the rate at which SWS need accumulated varied greatly with genotype. This conclusion was confirmed in a "dose-response" study of sleep loss and changes in delta power; delta power strongly depended on both the duration of prior wakefulness and genotype. We followed the segregation of the rebound of delta power after sleep deprivation in 25 BXD recombinant inbred strains by quantitative trait loci (QTL) analysis. One "significant" QTL was identified on chromosome 13 that accounted for 49% of the genetic variance in this trait. Interestingly, the rate at which SWS need decreases did not vary with genotype in any of the 31 inbred strains studied. These results demonstrate, for the first time, that the increase of SWS need is under a strong genetic control, and they provide a basis for identifying genes underlying SWS homeostasis.

Modelling the effect of surveillance programmes on spread of bovine herpesvirus 1 between certified cattle herds

For the eradication of an infectious agent, like bovine herpesvirus 1 (BHV-1), surveillance and certification can be used to reduce the transmission between herds. The goal of surveillance is that a certified herd that becomes infected is detected timely so that infection of several other certified herds is prevented. What counts is whether the reproduction ratio R, i.e. the average number of certified herds infected by one infected certified herd can be kept below 1. To support policy makers in making decisions about the minimal demands for a surveillance programme in an eradication campaign of BHV-1 in cattle, two mathematical models were investigated. With these models, the basic reproduction ratio between herds was calculated. The surveillance programmes were characterised with sample size, sampling frequency, test sensitivity, herd size, vaccination status, and contacts between herds. When R between herds is below 1, then the surveillance programme is sufficiently good to prevent spread of infection, provided that R is estimated well. In the model based on bulk milk testing sample size was replaced by a threshold at which bulk milk can be found positive. The R between herds was mainly influenced by the vaccination status, sampling frequency, and contacts between herds. Herd size moderately affected the outcome. Test sensitivity and sample size, however, were of minor importance. If herds of 50 cows became free of BHV-1 without vaccination, then spread of infection between herds might be prevented when animals within herds are sampled once a year (milk or blood samples). This frequency needs to be intensified, being twice a year, for larger herds and/or herds with extensive contacts with other herds. When bulk milk is sampled instead, sampling should be done at least every 5 months and more intensively, being each month, with larger herd sizes and more contacts between herds.

Interobserver reproducibility in reporting on 99mTc-DMSA scintigraphy for detection of late renal sequelae

This study was designed to evaluate the interobserver variability in reporting on 99mTc-dimercaptosuccinic acid (DMSA) scanning performed 6 mo after an acute episode of pyelonephritis for the detection of late renal sequelae.

METHODS

Forty-six children were selected, who had early and late DMSA studies for evaluation of acute pyelonephritic lesions as well as sequelae. Three observers reported independently and separately on the early and late DMSA scans and, in a second step, on the late scan in the presence of the early scan. Interobserver reproducibility was evaluated for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison.

RESULTS

Complete agreement between the three observers was reached in 75%, 78%, and 77% for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison, respectively.

CONCLUSION

Interobserver reproducibility was high and was comparable for both early and late DMSA scintigraphy.

[Outbreak of bovine virus diarrhea on Dutch dairy farms induced by a bovine herpesvirus 1 marker vaccine contaminated with bovine virus diarrhea virus type 2]

On 23 February 1999, the Dutch Animal Health Service advised all Dutch veterinary practices to postpone vaccination against bovine herpesvirus 1 (BHV1) immediately. The day before severe disease problems were diagnosed on four dairy farms after vaccination with the same batch of BHV1 marker vaccine. Using monoclonal antibodies, bovine virus diarrhoea virus (BVDV) type 2 was found in the vaccine batch. This paper describes an outbreak of BVDV type 2 infection caused by the use of a batch of modified live BHV1 marker vaccine contaminated with BDVD. Sources of information used were reports of farm visits, minutes of meetings, laboratory results, and oral communications from the people involved. The first symptoms of disease were observed on average six days after vaccination. Morbidity was high on 11 of the 12 farms. On five farms more than 70% of the animals became ill, while on one farm no symptoms could be detected. During the first week after vaccination, feed intake and milk production decreased. During the second week, some animals became clinically diseased having nasal discharge, fever, and diarrhoea. At the end of the second week and at the start of the third week, the number of diseased animals increased rapidly, the symptoms became more severe, and some animals died. Mortality varied among herds. Necropsy most often revealed erosions and ulcers of the mucosa of the digestive tract. In addition, degeneration of the liver, hyperaemia of the abomasum, and swollen mesenterial lymph nodes and swollen spleen were found. On 11 of the 12 farms all animals were culled between 32 and 68 days after vaccination after an agreement was reached with the manufacturer of the vaccine. This was the third outbreak of BVD in cattle after administration of a contaminated vaccine in the Netherlands. The possibilities to prevent contamination of a vaccine as a consequence of infection of fetal calf serum with BVDV are discussed. Improvement of controls to prevent contamination before and during vaccine production, and improvement of the monitoring of side-effects is necessary.

Efficacy of a live glycoprotein E-negative bovine herpesvirus 1 vaccine in cattle in the field

To assess the efficacy of a live glycoprotein E-negative bovine herpesvirus 1 (BHV1) vaccine to reduce transmission of BHV1 in cattle, a randomised, double-blind, placebo-controlled field trial including 84 herds was conducted in the Netherlands. The incidence of BHV1 infections during 17 months was monitored by detecting antibodies against BHV1 glycoprotein E. In the placebo-treated group 214 seroconversions in 3985 paired sera, and in the vaccinated group 67 seroconversions in 3601 paired sera were detected. Based on these data, the transmission ratio R(0) was estimated for each treatment, using the maximum likelihood approach and the martingale approach. In placebo-treated herds R(0) was 2.5 (CI 1.4-3.1) using maximum likelihood and 2.8 (S.E. 0.4) using the martingale approach. In the vaccinated group these estimations were 1.2 (CI 0.5-1.5) and 1.5 (S.E. 0.4) respectively. The vaccinated and placebo-treated group differed significantly in transmission of BHV1. These results suggest that the use of this live gE-negative BHV1 vaccine will reduce the incidence and transmission of BHV1 infections in the field.

Comparison of transthoracic echocardiography with second harmonic imaging with transesophageal echocardiography in the detection of right to left shunts

We compared the use of transthoracic echocardiography with second harmonic imaging after a peripheral intravenous injection of an agitated saline solution with transesophageal echocardiography (TEE) in the detection of right to left shunts at the cardiac and pulmonary level. Second harmonic mode transthoracic echocardiography and TEE are equally sensitive in detecting right to left shunts in patients undergoing a daily routine TEE.

Blood and brain magnesium in inbred mice and their correlation with sleep quality

A strong genetic component in the regulation of blood magnesium (Mg) levels has been demonstrated. The regulation and distribution of brain Mg levels, however, have never been assessed. Herein we report on the genetic variation of peripheral and central Mg levels in six inbred strains of mice. In addition, the possible involvement of Mg in sleep regulation was assessed by establishing correlations between Mg and sleep parameters obtained before and after a 6-h sleep deprivation. Although genotype strongly determined blood Mg levels, it did not affect brain Mg, suggesting that central and peripheral Mg are regulated differently. Central Mg displayed a highly structure-specific distribution with frontal cortex having the highest and brain stem the lowest values. Whereas for the amount and distribution of baseline sleep only marginal correlations with Mg were found, Mg contents in four of nine brain structures were highly positively correlated with the length of slow-wave sleep episodes during recovery. This relationship suggests that higher levels of Mg in specific brain sites promote sleep quality as part of a recovery process.

Venous pooling during nitrate-stimulated tilt testing in patients with vasovagal syncope

AIMS

To investigate the importance of venous pooling and variation in venous tone during nitrate-stimulated tilt testing in patients.

METHODS

Ten patients with a history of vasovagal syncope underwent an upright tilt test after an injection of 99mTc-labelled albumin. A gamma camera was positioned at the level of the lower legs. The patients were tilted to 90 degrees for 30 min or until symptoms developed. In those subjects who did not show any symptoms before the end of the 30-min period, isosorbide dinitrate (ISDN) 5 mg was given sublingually and the test was prolonged for a maximum of 15 min.

RESULTS

Nine of 10 patients needed nitrate stimulation to develop symptoms, and one patient remained symptom free following ISDN administration. Measurement of radioactivity revealed no significant increase in calf volume after nitrate stimulation (the mean volume increase was 77% before ISDN stimulation and a further 0.9% afterwards).

CONCLUSIONS

The higher sensitivity for vasovagal syncope during upright tilt testing after administration of sublingual ISDN is not due to an increase in venous pooling in the lower extremities.

Prediction of functional outcome by quantification of sestamibi and BMIPP after acute myocardial infarction

Iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) can be used to image myocardial fatty acid regional distribution and utilisation with single-photon emission tomography (SPET). By visual analysis, a mismatching with regional uptake of BMIPP less than that of a perfusion tracer has been shown to predict myocardial viability and functional improvement after restoration of flow in patients with myocardial infarction. The current study aimed to evaluate a newly developed quantitative method of analysis of sestamibi and BMIPP uptake for the prediction of functional recovery after revascularization in patients with acute infarction. BMIPP and gated sestamibi SPET studies at rest were obtained before and >3 months after revascularization in 18 patients with recent infarction. A colour-coded polar map was generated from the comparison of sestamibi and BMIPP uptake. Depending on the relative distribution of the two tracers, different patterns of uptake were identified and their extent expressed as percentages of the surface of the whole left ventricle and of the three main coronary artery territories. At follow-up, recovery was defined as a > or =5% increase in ejection fraction compared with baseline. Receiver-operating characteristic curve analysis was performed to analyse the data. At baseline, significant correlations were found between ejection fraction and the % surface with decreased sestamibi or BMIPP uptake (r=-0.68, P= 0.001, and r=-0.72, P<0.0001, respectively). When combining both tracers, ejection fraction was significantly associated with the extent of myocardium showing decreased sestamibi uptake with lower BMIPP uptake (mismatching; r=-0.68, P=0.001). At follow-up, significant functional recovery was found in 13/18 patients. By ROC curve analysis, the optimal pattern of distribution predicting recovery was a mismatching with uptake of sestamibi <70% and uptake of BMIPP at least 10% lower. For this parameter, optimal cut-off of extent was 10% of the whole left ventricle surface (sensitivity 69%, specificity 80%, accuracy 72%) and 25% of the infarct-related arterial territory (sensitivity 77%, specificity 80%, accuracy 78%). The areas under the curve were 79% for the left ventricle surface and 72% for the individual arterial territories. These results suggest that in patients with acute infarction, quantitative analysis of sestamibi and BMIPP could offer an objective and reproducible method for estimating the severity of cardiac dysfunction and predicting the evolution of ejection fraction after revascularization.

Arbuscular mycorrhiza development regulates the mRNA abundance of Mtaqp1 encoding a mercury-insensitive aquaporin of Medicago truncatula

The genome of the model legume Medicago truncatula Gaertn. was screened for the presence of genes encoding tonoplast intrinsic proteins, and a gene family was identified. The cDNA fragments of two members of the multigene family were cloned from roots inoculated with an arbuscular mycorrhizal fungus. Transcript accumulation in roots could be detected for both cDNA fragments, but only one gene was induced in the symbiosis when compared to non-mycorrhizal control roots. A full-length cDNA clone was obtained from the arbuscular-mycorrhiza-regulated gene, and injection of in-vitro-transcribed RNA into Xenopus oocytes revealed that the encoded protein MtAQP1 specifically facilitates water transport. The possible role of MtAQP1 in buffering osmotic fluctations in the highly compartmented vacuole of arbuscule cells is discussed.

Evaluating control strategies for outbreaks in BHV1-free areas using stochastic and spatial simulation

Several countries within the EU have successfully eradicated bovine herpesvirus type I (BHV1), while others are still making efforts to eradicate the virus. Reintroduction of the virus into BHV1-free areas can lead to major outbreaks - thereby causing severe economic losses. To give decision-makers more insight into the risk and economic consequences of BHV1 reintroduction and into the effectiveness of various control strategies, we developed the simulation model InterIBR. InterIBR is a dynamic model that takes into account risk and uncertainty and the geographic location of individual farms. Simulation of a BHV1-outbreak in the Netherlands starts with introduction of the virus on a predefined farm type, after which both within-farm and between-farm transmission are simulated. Monitoring and control measures are implemented to simulate detection of the infection and subsequent control. Economic consequences included in this study are related to losses due to infection and costs of control. In the simulated basic control strategy, dairy farms are monitored by monthly bulk-milk tests and miscellaneous farms are monitored by half-yearly serological tests. After detection, movement-control measures apply, animal contacts are traced and neighbour farms are put on surveillance. Given current assumptions on transmission dynamics, we conclude that a strategy with either rapid removal or vaccination of infected cattle does not reduce the number of infected farms compared to this basic strategy - but will cost more to control. Farm type with first introduction of BHV1 has a considerable impact on the expected number of secondarily infected farms and total costs. To limit the number of infected farms and total costs due to outbreaks, we suggest intensifying the monitoring program on farms with a high frequency of cattle trade, and monthly bulk-milk testing on dairy farms.

The transcription factor DBP affects circadian sleep consolidation and rhythmic EEG activity

Albumin D-binding protein (DBP) is a PAR leucine zipper transcription factor that is expressed according to a robust circadian rhythm in the suprachiasmatic nuclei, harboring the circadian master clock, and in most peripheral tissues. Mice lacking DBP display a shorter circadian period in locomotor activity and are less active. Thus, although DBP is not essential for circadian rhythm generation, it does modulate important clock outputs. We studied the role of DBP in the circadian and homeostatic aspects of sleep regulation by comparing DBP deficient mice (dbp-/-) with their isogenic controls (dbp+/+) under light-dark (LD) and constant-dark (DD) baseline conditions, as well as after sleep loss. Whereas total sleep duration was similar in both genotypes, the amplitude of the circadian modulation of sleep time, as well as the consolidation of sleep episodes, was reduced in dbp-/- under both LD and DD conditions. Quantitative EEG analysis demonstrated a marked reduction in the amplitude of the sleep-wake-dependent changes in slow-wave sleep delta power and an increase in hippocampal theta peak frequency in dbp-/- mice. The sleep deprivation-induced compensatory rebound of EEG delta power was similar in both genotypes. In contrast, the rebound in paradoxical sleep was significant in dbp+/+ mice only. It is concluded that the transcriptional regulatory protein DBP modulates circadian and homeostatic aspects of sleep regulation.