TEMP/TDM et scintigraphie osseuse en cancérologie : impact d’une acquisition scannographique basse dose chez les patients avec foyer isolé suspect ou de nature indéterminée

AimTo evaluate the usefulness of a low dose SPECT/CT and the added value of an additional “diagnostic” centred CT-scan in cancer patients with a solitary focus observed on planar whole-body bone scintigraphy (PWBS) and classified as indeterminate or suspicious.Material and methodsSixty consecutive patients underwent a low dose SPECT/CT acquisition (120 kV, 30 mAs, 3 mm slice thickness) followed by a “diagnostic” CT-scan (120 kV, 100 mAs, 1.25 mm slice thickness) centred on the focus. The first observer considered prospectively WBS, low-dose SPECT/CT and finally the centred SPECT/CT. A blinded review was performed by a second observer.ResultsPWBS depicted solitary indeterminate or suspicious foci in 38 and 22 patients, respectively. SPECT/CT acquisitions clarified 73% (44/60) of the foci. Additional diagnostic CT-scan altered low-dose SPECT/CT results in nine patients. Additional foci (not found by PWBS) located outside the scanning area of the centred diagnostic CT-scan were found in 20 patients. Inter observer agreement for PWBS, low-dose SPECT/CT and diagnostic SPECT/CT was equal to 0.542, 0.68 and 0.694, respectively. ROC analysis showed no difference between low-dose SPECT/CT and diagnostic SPECT/CT for observer 1 and observer 2.ConclusionThis study shows that a conventional low-dose SPECT/CT in patients presenting with a solitary focus on PWBS is sufficient to improve both accuracy and inter observer variability of bone scanning. A CT volume session should not be limited to the area of the solitary focus since additional foci located outside the centred CT-scan frequently occurred.     

A novel,stable bioradical

Several cellular systems have shown a novel EPR spectrum at 77 K, comprising a slightly anisotropic doublet centred on the free-spin g-value, with a hyperfine splitting of ca. 120 G. It is suggested that this species is an occluded protein radical centred on a tryptophan unit.     

Climatic and biogeographical associations of southern African dung beetles (Coleoptera: Scarabaeidae s. str.)

Climatic and biogeographical associations of southern African dung beetles (Scarabaeinae, Coprinae) were analysed from a collection amassed between 1971 and 1986. Endemism to Africa south of 15°S was much greater in southwesterly climates (winter rainfall, bimodal spring/autumn rainfall, arid late summer rainfall) than to the north‐east in the moist, mid‐summer rainfall region. Major biogeographical groups centred to the south‐west comprised predominantly southern African endemics, Western/Eastern Cape coast, Karoo, Karoo/Namib, northern Namibia and the south‐western Kalahari. Biogeographical groups centred on the south‐eastern highlands and the subtropical east coast (mid‐summer rainfall) also comprised predominantly southern African endemics. All other major groups centred to the north‐east in the mid‐summer rainfall region comprised predominantly species with widespread tropical biogeographical affiliations, pan‐southern Africa but centred in the east, pan‐mid‐summer rainfall region, eastern mid‐summer rainfall region, tropical east Zimbabwe/central Moçambique, subtropical/tropical game reserves (non‐ruminant dung specialists). There were cross‐climatic differences in taxonomic composition of the fauna. Within the winter rainfall region, percentage species composition of Scarabaeinae was greater whereas that of the coprine tribe, Onthophagini, was lower than within the other three climatic regions. Percentage species richness of most other tribes of Coprinae differed little between most climates but that of Scarabaeinae declined from west to east (Canthonini, Scarabaeini), east to west (Sisyphini) or to either side of the late summer rainfall region (Gymnopleurini).     

Free mycolic acids as criteria in the classification of Nocardia and the 'rhodochrous' complex.

The methyl esters of free mycolic acids from representative strains of Nocardia asteroides, N. brasiliensis, N. caviae and the 'rhodochrous' complex were subjected to detailed mass spectral analysis. The anhydromycolic esters of the Nocardia strains consisted of homologous series containing from zero to three double bonds, with the main components of the parent mycolic acids centred on C52 to C54 (range C46 to C58). The anhydromycolates from one rhodochrous strain, Nocardia opaca, had a molecular weight range similar to the nocardiae (C46 to C57) but the remaining rhodochrous strains gave an homologous series of anhydromycolates containing from zero to two double bonds, with the main components of the parent mycolic acids centred on C38, C42, C44 or C46 (total range from C34 to C50). The mycolic acids from the rhodochrous strains with chain lengths centred around C40 form a group intermediate in size between corynomycolic acids (centred around C32) and nocardomycolic acids (centred around C50). These data weaken the case for retaining the 'rhodochrous' complex in the genus Mycobacterium, and also show that many rhodochrous strains can be distinguished from true nocardiae and corynebacteria. These results confirm the value of lipid characters in the classification of these organisms.     

Dielectric behaviour of frozen DNA in solution

In this article, measurements are reported on ice and frozen DNA solutions between 100 Hz–10 MHz. Pure ice is shown to exhibit single relaxation behaviour, which confirms previous work taken over a more restricted frequency range. The frozen DNA solution displays double‐dispersion behaviour. One dispersion centred around 3 kHz is due to a defect mechanism while the other, centred around 2 MHz, may be attributed to counterion flow through the water immediately adjacent to the DNA molecule. Bioelectromagnetics 20:40–45, 1999. © 1999 Wiley‐Liss, Inc.     

Primate anterior cingulate cortex: where motor control, drive and cognition interface

Controversy surrounds the function of the anterior cingulate cortex. Recent discussions about its role in behavioural control have centred on three main issues: its involvement in motor control, its proposed role in cognition and its relationship with the arousal/drive state of the organism. I argue that the overlap of these three domains is key to distinguishing the anterior cingulate cortex from other frontal regions, placing it in a unique position to translate intentions to actions.     

Endpiece: How to buy gadgets

Objective To assess the effect of additional training of practice nurses and general practitioners in patient centred care on the lifestyle and psychological and physiological status of patients with newly diagnosed type 2 diabetes.Design Pragmatic parallel group design, with randomisation between practice teams to routine care (comparison group) or routine care plus additional training (intervention group); analysis at one year, allowing for practice effects and stratifiers; self reporting by patients on communication with practitioners, satisfaction with treatment, style of care, and lifestyle.Setting 41 practices (21 in intervention group, 20 in comparison group) in a health region in southern England.Subjects 250/360 patients (aged 30-70 years) diagnosed with type 2 diabetes and completing follow up at one year (142 in intervention group, 108 in comparison group).Intervention 1.5 days’ group training for the doctors and nurses—introducing evidence for and skills of patient centred care and a patient held booklet encouraging questions.Main outcome measures Quality of life, wellbeing, haemoglobin A_1c and lipid concentrations, blood pressure, body mass index (kg/m²).Results Compared with patients in the C group, those in the intervention group reported better communication with the doctors (odds ratio 2.8; 95% confidence interval 1.8 to 4.3) and greater treatment satisfaction (1.6; 1.1 to 2.5) and wellbeing (difference in means (d) 2.8; 0.4 to 5.2). However, their body mass index was significantly higher (d=2.0; 0.3 to 3.8), as were triglyceride concentrations (d=0.4 mmol/l; 0.07 to 0.73 mmol/l), whereas knowledge scores were lower (d=−2.74; −0.23 to −5.25). Differences in lifestyle and glycaemic control were not significant.Conclusions The findings suggest greater attention to the consultation process than to preventive care among trained practitioners; those committed to achieving the benefits of patient centred consulting should not lose the focus on disease management.

Key messages

• A training programme in patient centred care for practitioners led to patients with newly diagnosed diabetes reporting better communication with doctors, greater wellbeing, and greater treatment satisfaction at one year, without loss of glycaemic control
• Knowledge scores were lower and weight and other cardiovascular risk factors higher among patients attending trained practice teams
• Trained practitioners may have found it difficult to integrate attention to wellbeing with management of disease risk
• Professionals using patient centred consulting should not lose the focus on disease

     

Sequence preferences in the binding to DNA of triostin A and TANDEM as reported by DNase I footprinting

Six or seven triostin-binding sites have been identified in a 160-base-pair DNA restriction fragment containing the tyr T promoter sequence. Each is centred round a CpG step, and the minimum binding site-size appears to be six base pairs. The sites are practically the same as those reported for echinomycin by DNase I digestion. Only two sites are protected by binding of TANDEM, the des-N-tetramethyl analogue of triostin A; they are centred around the sequences ATA or TAT.     

Velarium control and visual steering in box jellyfish

Directional swimming in the box jellyfish Tripedalia cystophora (cubozoa, cnidaria) is controlled by the shape of the velarium, which is a thin muscular sheet that forms the opening of the bell. It was unclear how different patterns of visual stimulation control directional swimming and that is the focus of this study. Jellyfish were tethered inside a small experimental tank, where the four vertical walls formed light panels. All four panels were lit at the start of an experiment. The shape of the opening in the velarium was recorded in response to switching off different combinations of panels. We found that under the experimental conditions the opening in the velarium assumed three distinct shapes during a swim contraction. The opening was (1) centred or it was off-centred and pocketed out either towards (2) a rhopalium or (3) a pedalium. The shape of the opening in the velarium followed the direction of the stimulus as long as the stimulus contained directional information. When the stimulus contained no directional information, the percentage of centred pulses increased and the shape of the off-centred pulses had a random orientation. Removing one rhopalium did not change the directional response of the animals, however, the number of centred pulses increased. When three rhopalia were removed, the percentage of centred pulses increased even further and the animals lost their ability to respond to directional information.     

Solution NMR study of the interaction between NTF2 and nucleoporin FxFG repeats

Interactions with nucleoporins containing FxFG repeat cores are crucial for the nuclear import of RanGDP mediated by nuclear transport factor 2 (NTF2). We describe here a solution NMR-based study that identifies primary and secondary FxFG-binding sites on NTF2 and accounts for a range of observations on the rate of NTF2 nuclear trafficking. We used three complementary NMR methods, namely amide group chemical shift titrations, NOE and cross-saturation measurements, to show that the major FxFG-binding site on the dimeric rat NTF2 (rNTF2) molecule is centred on Trp7 and is formed by residues from both NTF2 chains. A secondary FxFG-binding site is located at the rNTF2 hydrophobic cavity and these two sites, together with a surface hydrophobic cluster centred on Trp112, merge into an elongated hydrophobic stripe on the rNTF2 surface. The primary site centred on Trp7 is lost in the rNTF2-W7A mutant that has been shown to bind FxFG nucleoporins with greatly reduced affinity, whereas the secondary site at the rNTF2 hydrophobic cavity is retained. The interface between NTF2 and FxFG nucleoporins detected by NMR is more extensive than that detected by X-ray crystallography, and the presence of a secondary site at the NTF2 hydrophobic cavity accounts for the unexpectedly rapid nuclear import of rNTF2-W7R recently observed by others. The structure of the binding interfaces on these transport factors provides a rationale for the specificity of their interactions with nucleoporins that, combined with their weak binding constants, facilitates rapid translocation through NPCs during nuclear trafficking.     

Reproduction of the long-tongued nectar bat Macroglossus minimus (Pteropodidae) in Brunei, Borneo

The long‐tongued nectar bat Macroglossus minimus lagochilus (Megachiroptera, Pteropodidae) is a small fruit bat inhabiting South‐east Asia. Its reproduction was studied in Brunei, Borneo, where individuals were usually captured in rainforest (Ulu Temburong). Adult females (n = 23) had body masses of 13.0–19.0 g, with forelimbs 3.83–4.33 cm in length. All adult females were pregnant, with pregnancies observed during every month except May, September and November when no adult females were captured. Female M. minimus in Brunei have a reproductive cycle that is consistent with a pattern of seasonal bimodal polyoestry. Most births appear to occur from November to May, during which time females experience two births: the first centred around November and December, and the second centred around April and May. These two birth seasons appear correlated to the two seasons of greater rainfall in Brunei: October to December, and April to July. Oestrous and mating apparently occur soon after each birth; however, there appears to be a 2‐ to 3‐month period of delayed embryonic development following the births centred around April and May. The data are consistent with embryonic development commencing around July and August (after a delay) for the births centred around November and December, and around December and January for the births centred around April and May. The data suggest that all adult females participate in each breeding season. Adult males (n = 20) had body masses of 12.5–18.0 g, with forelimbs 3.91–4.26 cm in length.     

Evidence of phytochrome involvement in the entrainment of the circadian rhythm of carbon dioxide metabolism in Bryophyllum

The rhythm of carbon dioxide output in Bryophyllum leaves was entrained on exposure to 0.25 h of white light every 24 h. Entrainment also occurred on similar exposure to monochromatic radiation in spectral bands centred at 660 nm and, to a lesser extent, at 730 nm, but a band centred at 450 nm was without effect. A skeleton irradiation programme comprising two 0.25-h exposures to white light per 24 h also entrained the rhythm when the intervening dark periods were either 7.5 h and 16 h, or 10.5 h and 13 h. The rhythm disappeared when the two exposures were separated by 11.5-h and 12-h dark periods. Regular 0.25-h exposures to red light separated by 11.75-h periods of darkness also resulted in loss of the rhythm. Red/far-red reversibility was observed in irradiation schedules having either one or two exposures to red light daily. In the latter case, far-red reversal of the effects of one of the exposures to red light resulted in entrainment of the rhythm by the other, instead of abolition of the rhythm. The occurrence of distinct red/far-red reversibility suggests strongly that phytochrome is the pigment involved in entrainment of this rhythm by cycles of light and darkness.Abbreviation LD light-dark rhythm     

Two membrane-bound b-type cytochromes in Nitrosomonas europaea

Abstract Membranes from Nitrosomonas europaea were found to contain two b -type cytochromes. One had an α-band centred at 562 nm and E _m,7=+ 155 mV; the other had an α-band maximum close to 558 nm and E _m,7=+ 40 mV. A b -type cytochrome ran at an apparent M _r of 32000 on lithium dodecyl sulphate/polyacrylamide gels at 4°C.     

Neural Responses in Parietal and Occipital Areas in Response to Visual Events Are Modulated by Prior Multisensory Stimuli

The effect of multi-modal vs uni-modal prior stimuli on the subsequent processing of a simple flash stimulus was studied in the context of the audio-visual ‘flash-beep’ illusion, in which the number of flashes a person sees is influenced by accompanying beep stimuli. EEG recordings were made while combinations of simple visual and audio-visual stimuli were presented. The experiments found that the electric field strength related to a flash stimulus was stronger when it was preceded by a multi-modal flash/beep stimulus, compared to when it was preceded by another uni-modal flash stimulus. This difference was found to be significant in two distinct timeframes – an early timeframe, from 130–160 ms, and a late timeframe, from 300–320 ms. Source localisation analysis found that the increased activity in the early interval was localised to an area centred on the inferior and superior parietal lobes, whereas the later increase was associated with stronger activity in an area centred on primary and secondary visual cortex, in the occipital lobe. The results suggest that processing of a visual stimulus can be affected by the presence of an immediately prior multisensory event. Relatively long-lasting interactions generated by the initial auditory and visual stimuli altered the processing of a subsequent visual stimulus.